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1
Haug, Joachim T., e Carolin Haug. "Beetle larvae with unusually large terminal ends and a fossil that beats them all (Scraptiidae, Coleoptera)". PeerJ 7 (14 ottobre 2019): e7871. http://dx.doi.org/10.7717/peerj.7871.
Testo completoAbstract (sommario):
Larvae, and especially fossil larvae, are challenging to deal with from a purely taxonomic view. Often one cannot determine which species the larvae belong to. Yet, larvae can still contribute to various scientific questions. Especially morphological traits of a fossil larva can be highly informative for reconstructing character evolution. Also the occurrence of specific larval types and larval characters in time and the disappearance of such forms can well be reconstructed also without being able to narrow down the phylogenetic relationship of a larva very far. Here, we report two new beetle larvae preserved in Baltic amber which are identified as representatives of Scraptiidae, based on an enlarged terminal end (‘9th abdomen segment’); this is only the third record of such larvae. In comparison to modern forms, the terminal ends of the two new fossil larvae is even larger in relation to the remaining body than in any known larva. Unfortunately, our knowledge of such larvae in the modern fauna is very limited. Still, one of the two already known fossil larvae of Scraptiidae also has a very long terminal end, but not as long as those of the two new fossils. These three fossil larvae therefore seem to possess a specific morphology not known from the modern fauna. This might either mean that they (1) represent a now extinct larval morphology, a phenomenon well known in other euarthropodan lineages, or that (2) these forms represent a part of the larval phase not known from modern day species as they have not been described yet; such cases occur in closely related lineages. In any case, the fossils expand the known diversity of larval morphologies.
2
Peña, Renato, e Silvie Dumas. "COMPORTAMIENTO ALIMENTARIO DE LA LARVA DEL HUACHINANGO DEL PACÍFICO Lutjanus peru (NICHOLS & MURPHY, 1922) (PERCOIDEI: LUTJANIDAE) AL INICIO DE LA ALIMENTACIÓN EXÓGENA". CICIMAR Oceánides 30, n. 2 (31 dicembre 2015): 7. http://dx.doi.org/10.37543/oceanides.v30i2.147.
Testo completoAbstract (sommario):
El comportamiento alimentario de larvas del huachinango del Pacífico fue estudiado bajo condiciones controladas, con énfasis especial durante el inicio de la alimentación exógena (al tercer día después de la eclosión). Durante un periodo de cinco minutos fueron observadas de manera individual diez larvas de L. peru, antes y después de ser alimentadas con rotíferos (Brachionus rotundiformis) y nauplios de copépodos (Euterpina acutifrons) en densidades de 5 presas/ml. Para describir parte del comportamiento relacionado con el evento de alimentación se registró el número de veces que las larvas adoptaron una “postura” de ataque, así como el número de ataques por larva a los diferentes tipos presa. Se observó que previo al suministro de alimento, las larvas despliegan tres tipos de conducta: nado, reposo, e impulso rápido. Una vez que fue suministrado el alimento, el patrón de conducta de las larvas cambió, independientemente del tipo de presa. La frecuencia de nado incrementó pero los desplazamientos fueron más cortos y pausas más frecuentes. El periodo de reposo de las larvas disminuyó significativamente y se observaron dos patrones de acción modal asociados directamente al proceso de alimentación: 1) postura sigmoide (“S”), adoptada posterior a la detección de una presa, 2) ataque, evento durante el cual la larva se impulsa espontáneamente en dirección de la presa, independientemente de si se logra o no la captura del alimento. Menos del 50 % de las larvas observadas desplegaron una postura de ataque y el número promedio de ataques por larva durante el tiempo de observación fue menor a 1.5, independientemente del tipo de presa. Los resultados son similares a los reportados para otras larvas de peces durante el inicio de la alimentación exógena y sugieren que los nauplios de copépodos son una presa adecuada durante la primera alimentación de las larvas de L. peru. Feeding behaviour of the Pacific red snapper Lutjanus peru (Nichols & Murphy, 1922) (Percoidei: Lutjanidae) larvae at the onset of exogenous feeding The behaviour of the Pacific red snapper Lutjanus peru larvae during the onset of exogenous feeding at day 3 after hatching at 26º C was studied. Ten larvae were directly observed during 5 min each before and after the addition of feed. Rotifers (Brachionus rotundiformis) and copepod nauplii (Euterpina acutifrons) were used as live feed at a density of 5 prey/ml. Larval behavior was described before and after prey addition. Also, the number of larvae that displayed an attack posture and the number of attacks per larvae during the observation period were recorded. Before prey addition, the larvae displayed three types of conduct: swimming, resting and fast impulse. This behavioral pattern changed with the presence of feed, regardless of prey type. The swimming conduct increased duration but changed to a short distance and frequent pauses. The resting conduct reduced its duration and two new modal action patterns associated to feeding were present: “S” posture after prey detection and the attack which consisted in a direct larval strike towards the prey and may include prey capture. Less than 50% of the observed larvae displayed the attack posture and the mean number of attacks per larvae was less than 1.5 during the observation period regardless of prey type. Results are similar to the reported for other species during the onset of exogenous feeding and suggest that copepod nauplii may be a more suitable prey during first feeding of L. peru.
3
Peña, Renato, e Silvie Dumas. "COMPORTAMIENTO ALIMENTARIO DE LA LARVA DEL HUACHINANGO DEL PACÍFICO Lutjanus peru (NICHOLS & MURPHY, 1922) (PERCOIDEI: LUTJANIDAE) AL INICIO DE LA ALIMENTACIÓN EXÓGENA". CICIMAR Oceánides 30, n. 2 (31 dicembre 2015): 7. http://dx.doi.org/10.37543/oceanides.v30i2.147.
Testo completoAbstract (sommario):
El comportamiento alimentario de larvas del huachinango del Pacífico fue estudiado bajo condiciones controladas, con énfasis especial durante el inicio de la alimentación exógena (al tercer día después de la eclosión). Durante un periodo de cinco minutos fueron observadas de manera individual diez larvas de L. peru, antes y después de ser alimentadas con rotíferos (Brachionus rotundiformis) y nauplios de copépodos (Euterpina acutifrons) en densidades de 5 presas/ml. Para describir parte del comportamiento relacionado con el evento de alimentación se registró el número de veces que las larvas adoptaron una “postura” de ataque, así como el número de ataques por larva a los diferentes tipos presa. Se observó que previo al suministro de alimento, las larvas despliegan tres tipos de conducta: nado, reposo, e impulso rápido. Una vez que fue suministrado el alimento, el patrón de conducta de las larvas cambió, independientemente del tipo de presa. La frecuencia de nado incrementó pero los desplazamientos fueron más cortos y pausas más frecuentes. El periodo de reposo de las larvas disminuyó significativamente y se observaron dos patrones de acción modal asociados directamente al proceso de alimentación: 1) postura sigmoide (“S”), adoptada posterior a la detección de una presa, 2) ataque, evento durante el cual la larva se impulsa espontáneamente en dirección de la presa, independientemente de si se logra o no la captura del alimento. Menos del 50 % de las larvas observadas desplegaron una postura de ataque y el número promedio de ataques por larva durante el tiempo de observación fue menor a 1.5, independientemente del tipo de presa. Los resultados son similares a los reportados para otras larvas de peces durante el inicio de la alimentación exógena y sugieren que los nauplios de copépodos son una presa adecuada durante la primera alimentación de las larvas de L. peru. Feeding behaviour of the Pacific red snapper Lutjanus peru (Nichols & Murphy, 1922) (Percoidei: Lutjanidae) larvae at the onset of exogenous feeding The behaviour of the Pacific red snapper Lutjanus peru larvae during the onset of exogenous feeding at day 3 after hatching at 26º C was studied. Ten larvae were directly observed during 5 min each before and after the addition of feed. Rotifers (Brachionus rotundiformis) and copepod nauplii (Euterpina acutifrons) were used as live feed at a density of 5 prey/ml. Larval behavior was described before and after prey addition. Also, the number of larvae that displayed an attack posture and the number of attacks per larvae during the observation period were recorded. Before prey addition, the larvae displayed three types of conduct: swimming, resting and fast impulse. This behavioral pattern changed with the presence of feed, regardless of prey type. The swimming conduct increased duration but changed to a short distance and frequent pauses. The resting conduct reduced its duration and two new modal action patterns associated to feeding were present: “S” posture after prey detection and the attack which consisted in a direct larval strike towards the prey and may include prey capture. Less than 50% of the observed larvae displayed the attack posture and the mean number of attacks per larvae was less than 1.5 during the observation period regardless of prey type. Results are similar to the reported for other species during the onset of exogenous feeding and suggest that copepod nauplii may be a more suitable prey during first feeding of L. peru.
4
HOANG, DUC HUY, e YEON JAE BAE. "Vietnamese species of Stenopsyche McLachlan (Trichoptera: Stenopsychidae)". Zootaxa 1624, n. 1 (29 ottobre 2007): 1–15. http://dx.doi.org/10.11646/zootaxa.1624.1.1.
Testo completoAbstract (sommario):
Larvae of the net-spinning caddisfly Stenopsyche McLachlan are very common in Vietnamese streams. Six species of Stenopsyche have previously been recorded from Vietnam. Based on comprehensive field studies throughout Vietnam between 2001 and 2003, the following species of Stenopsyche were recognized from the country: S. angustata Martynov 1930 (new Vietnamese record: male, female, and larva), S. dakpri sp. nov. (male, female, and larva), S. siamensis Martynov 1931 (new Vietnamese record: male, female, and larva), S. ulmeri Navás 1932 (male, female, and larva), and two additional larval forms (Stenopsyche sp. 1 and Stenopsyche sp. 2). Stenopsyche coomani Navás 1932, S. fissa Navás 1932, and S. vicina Navás 1932 are designated as nomina dubia. The new species and the newly discovered stages (female and larva of S. angustata Martynov and S. ulmeri Navás and larve of Stenopsyche sp. 1 and Stenopsyche sp. 2) are described and figured. Diagnoses, taxonomic remarks, and keys to males and larvae of all known Vietnamese Stenopsyche species are provided.
5
Sheehan, Gerard, Laura Tully e Kevin A. Kavanagh. "Candida albicans increases the pathogenicity of Staphylococcus aureus during polymicrobial infection of Galleria mellonella larvae". Microbiology 166, n. 4 (1 aprile 2020): 375–85. http://dx.doi.org/10.1099/mic.0.000892.
Testo completoAbstract (sommario):
This study detailed the responses of Galleria mellonella larvae to disseminated infection caused by co-infection with Candida albicans and Staphylococcus aureus . Doses of C. albicans (1×105 larva−1) and S. aureus (1×104 larva−1) were non-lethal in mono-infection but when combined significantly (P<0.05) reduced larval survival at 24, 48 and 72 h relative to larvae receiving S. aureus (2×104 larva−1) alone. Co-infected larvae displayed a significantly higher density of S. aureus larva−1 compared to larvae infected solely with S. aureus . Co-infection resulted in dissemination throughout the host and the appearance of large nodules. Co-infection of larvae with C. albicans and S. aureus (2×104 larva−1) resulted in an increase in the density of circulating haemocytes compared to that in larvae infected with only S. aureus . Proteomic analysis of co-infected larval haemolymph revealed increased abundance of proteins associated with immune responses to bacterial and fungal infection such as cecropin-A (+45.4-fold), recognition proteins [e.g. peptidoglycan-recognition protein LB (+14-fold)] and proteins associated with nodule formation [e.g. Hdd11 (+33.3-fold)]. A range of proteins were also decreased in abundance following co-infection, including apolipophorin (−62.4-fold), alpha-esterase 45 (−7.7-fold) and serine proteinase (−6.2-fold). Co-infection of larvae resulted in enhanced proliferation of S. aureus compared to mono-infection and an immune response showing many similarities to the innate immune response of mammals to infection. The utility of G. mellonella larvae for studying polymicrobial infection is highlighted.
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Zakiyabarsi, Furqan, Muhammad Niswar e Zahir Zainuddin. "Crab Larvae Counter Using Image Processing". EPI International Journal of Engineering 2, n. 2 (31 agosto 2019): 127–31. http://dx.doi.org/10.25042/epi-ije.082019.06.
Testo completoAbstract (sommario):
Very small larval size, high mortality rate of crab larvae, the absence of an accurate crab larva counter at affordable price, the density of larvae that are not known accurately, the ratio of feed that not in accordance with the number of larvae to damage water quality and cannibalism, water quality can not be adjusted to the density of distribution, and economically unprofitable both in terms of feed efficiency and buying and selling transactions. By knowing the number of crab larvae accurately the survival rate of crab larvae increases and is economically beneficial. In this study larvae counters were designed and developed. This tool uses digital imagery to detect and count the crab larvae zoea-1 phase. The accuracy of crab larva counter is 89,8%.
7
Welborn, J., e D. Manahan. "Taurine metabolism in larvae of marine invertebrate molluscs (Bilvalvia, Gastropoda)". Journal of Experimental Biology 198, n. 8 (1 gennaio 1995): 1791–99. http://dx.doi.org/10.1242/jeb.198.8.1791.
Testo completoAbstract (sommario):
Nonfeeding larvae of the gastropod Haliotis rufescens maintained a constant amount of taurine during embryonic and larval development and, since no de novo synthesis of taurine was observed in these larvae, the maternal endowment of taurine to the egg was sufficient for larval development to metamorphosis. In contrast, feeding larvae of the bivalve Crassostrea gigas increased their taurine content by a factor of 43 during growth to metamorphosis (from 86 to 311 µm, valve length). Taurine was not present in algae used to feed the larvae, suggesting that de novo synthesis of taurine by the larvae met their requirements. In unfed larvae, cysteic acid, cysteine sulfinic acid and hypotaurine were labeled from a [35S]cysteine precursor, but taurine was not. Hyperosmotic treatment (from 33 to 44 salinity for up to 3 h) did not induce taurine synthesis in unfed larvae. However, larvae fed the alga Isochrysis galbana up-regulated their taurine synthesis from [35S]cysteine by a factor of 11 (fed, 11.7±2.2 fmol taurine larva-1 h-1; unfed controls, 1.08±0.33 fmol taurine larva-1 h-1; means ± s.e.m.). Fed larvae also synthesized taurine from [35S]methionine (18.4 fmol larva-1 h-1). I. galbana contained 5 fmol cell-1 of cysteine and methionine (combined) and, based on known feeding rates, we calculated that there were sufficient taurine precursors in the algae to supply the taurine requirements of growing larvae. The lack of significant de novo taurine synthesis reported for adult bivalve molluscs has led to the conclusion that taurine is a dietary requirement. Our findings for larval forms differ in that there is significant de novo synthesis of taurine during development.
8
Zavala-Leal, I., S. Dumas-Lapage e R. Peña-Martinez. "ORGANOGÉNESIS DURANTE EL PERIODO LARVAL EN PECES". CICIMAR Oceánides 26, n. 2 (4 dicembre 2011): 19. http://dx.doi.org/10.37543/oceanides.v26i2.100.
Testo completoAbstract (sommario):
La presencia de un periodo larval caracteriza a los peces con ontogenia indirecta. Este periodo de desarrollo implica una serie de transformaciones encaminadas a la adquisición de las características biológicas y ecológicas propias de la especie; y en muchos casos culmina con cambios de distribución y hábitos alimenticios. El periodo larval incluye cuatro estadios de desarrollo: larva vitelina, larva pre-flexión, larva flexión y larva post-flexión. Cada estadio de desarrollo presenta características asociados a cambios en las diferentes prioridades durante el crecimiento. De esta forma, durante los estadios de larva vitelina y larva pre-flexión, la prioridad es incrementar las posibilidades de supervivencia a través de enfatizar la capacidad alimenticia y de evasión de depredadores, lo cual se ve reflejado en una mayor diferenciación de estructuras asociadas a estas funciones. La larva flexión se caracteriza por presentar un mayor grado de funcionalidad de los órganos y estructuras desarrolladas anteriormente. Finalmente, durante el estadio de larva post-flexión se presentan los cambios más agudos con respecto a la funcionalidad de los órganos ya desarrollados. En el presente trabajo se realiza la descripción del desarrollo de estos órganos para cada uno de los estadios de desarrollo larval, haciendo referencia en las diferencias y semejanzas entre distintas especies de importancia comercial. Organogenesis during the larval period in fishes The presence of a larval period is characteristic of fishes with an indirect ontogeny. Many transformations involved in this period lead to the acquisition of biological and ecological characteristics of each species, that culminate in changes in distribution and feeding habits. Larval period includes four developmental stages: viteline larvae, pre-flexion larvae, flexion larvae and post-flexion larvae. Each developmental stage showed inherent characteristics associated with changes in priorities during growth. During the viteline larvae and pre-flexion larval stages, priority is about increasing the survival possibility through an increase in the capacity of feeding and escaping predators which is reflected in the development of structures involved in these activities. The flexion larva is characterized by a greater degree of functionality of organs and structures previously developed. Finally, the post-flexion larvae show the most drastical changes in the functionality of developed organs. In this work, we present a description of the development of these organs, taking into account differences and similarities between species.
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OROZCO, JESUS, e LUIS C. PARDO-LOCARNO. "Description of immature stages of three species of American Cetoniinae (Coleoptera: Scarabaeidae: Cetoniinae)". Zootaxa 769, n. 1 (14 dicembre 2004): 1. http://dx.doi.org/10.11646/zootaxa.769.1.1.
Testo completoAbstract (sommario):
The larvae and pupae of three Cetoniinae scarab beetles, Gymnetis pantherina Blanchard, 1837; Gymnetis holosericea (Voet, 1779), and Euphoria precaria Janson, 1881 from Colombia are described. Multiple color patterns of adults and key larval characters are illustrated for each species for the first time. The described larvae of Gymnetis MacLeay are included in a key to the larvae of the genus, now with five species; and Euphoria precaria is added to the extant key of the known Euphoria larvae. New distributional records for the country are presented and some comments on the biology of the species in captivity are provided.Se describe la larva y la pupa de tres escarabajos cetoninos: Gymnetis pantherina Blanchard, 1837; Gymnetis holosericea (Voet, 1779), y Euphoria precaria Janson, 1881 de Colombia. Los caracteres larvales estudiados y las multiples formas de coloraci n de los adultos de las especies tratadas son ilustrados por primera vez. Una clave para las larvas de las especies de Gymnetis descritas al momento es elaborada y la clave existente para las larvas de Euphoria es actualizada con la nueva informaci n. El rango distribucional de las especies en Colombia es ampliado con nuevos registros y se presenta informaci n sobre la biolog a de las especies en cautiverio.
10
Minoshima, Yûsuke N. "First known larva of omicrine genus Psalitrus d’Orchymont (Coleoptera, Hydrophilidae)". Deutsche Entomologische Zeitschrift 66, n. 1 (25 giugno 2019): 107–18. http://dx.doi.org/10.3897/dez.66.34300.
Testo completoAbstract (sommario):
The larval morphology of the water scavenger beetlePsalitrusyamatensisHoshina & Satô, 2005 is described based on a specimen collected from Fukuoka Prefecture, Kyushu, Japan. This is the first description of the larval morphology of the hydrophilid genusPsalitrusd’Orchymont, 1919, as well as the first description of larval chaetotaxy of the tribe Omicrini. Species-level identification of the larva was performed using DNA barcoding of a molecular marker: a 658 bp fragment of the mitochondrial cytochrome oxidase I. A description including chaetotaxy of head capsule and head appendages, diagnosis, and illustrations of the larva is provided.Psalitruslarvae can be distinguished from other known larvae of the tribe Omicrini by the morphology of the head and legs. The larva shares characters with other known larvae of Omicrini; potential plesiomorphies are shared with Cylominae and aquatic hydrophilids; some characters are also shared with larvae of Megasternini and Sphaeridiini.
11
Mehdi, N. M., H. F. Al-Rubeae e M. A. Ali. "Laboratory evaluation of azadirachtin isolated from Melia azedarach L. fruits against Anopheles pulcherrimus Theobald (Diptera: Culicidae)". Journal of Biotechnology Research Center 8, n. 2 (1 giugno 2014): 51–56. http://dx.doi.org/10.24126/jobrc.2014.8.2.331.
Testo completoAbstract (sommario):
Efficacy of different concentration of azadirachtin isolated from fruits of Melia azedarach was investigated on the different stages of Anopheles pulcherrimus under lab. condition. Results showed that there was non-significant reduction in eggs hatching rate. There were high significant in larval mortalities which were depending on concentration. Different larval deformities were found. Second instars larvae were more sensitive then fourth larva instar , LC50 and LC90 for the second instars larvae were 35.99 and 67.99 ppm respectively and for the fourth instars larvae it was 63.09 and 139.8 respectively, significant prolongation in larval development period.
12
Nagler, Christina, Jens T. Høeg, Carolin Haug e Joachim T. Haug. "A possible 150 million years old cirripede crustacean nauplius and the phenomenon of giant larvae". Contributions to Zoology 86, n. 3 (23 ottobre 2017): 213–27. http://dx.doi.org/10.1163/18759866-08603002.
Testo completoAbstract (sommario):
The larval phase of metazoans can be interpreted as a discrete post-embryonic period. Larvae have been usually considered to be small, yet some metazoans possess unusually large larvae, or giant larvae. Here, we report a possible case of such a giant larva from the Upper Jurassic Solnhofen Lithographic limestones (150 million years old, southern Germany), most likely representing an immature cirripede crustacean (barnacles and their relatives). The single specimen was documented with up-to-date imaging methods (macro-photography, stereo-photography, fluorescence photography, composite imaging) and compared with modern cirripede larvae. The identification is based on two conspicuous spine-like extensions in the anterior region of the specimen strongly resembling the so-called fronto-lateral horns, structures exclusively known from cirripede nauplius larvae. Notably, at 5 mm in length the specimen is unusually large for a cirripede nauplius. We therefore consider it to be a giant larva and discuss possible ecological and physiological mechanisms leading to the appearance of giant larvae in other lineages. Further findings of fossil larvae and especially nauplii might give new insights into larval evolution and plankton composition in the past.
13
Pedersen, Eric J., Ryan R. E. Stanley, Paul V. R. Snelgrove e Frédéric Guichard. "Experimental evidence for concentration-dependence and intraspecific variation of movement behaviour in American lobster (Homarus americanus) larvae". Canadian Journal of Zoology 95, n. 10 (ottobre 2017): 759–70. http://dx.doi.org/10.1139/cjz-2016-0100.
Testo completoAbstract (sommario):
Predicting dispersal paths of marine larvae with extended pelagic durations, such as American lobster (Homarus americanus H. Milne Edwards, 1837), requires understanding the cues to which larvae respond, and how that response reflects changes in larval behaviour. If larvae respond to conspecific presence by varying their movement, then this behaviour can bias laboratory estimates of environmental responses. We tested whether larvae actively decreased their local intraspecific density by measuring how the vertical distribution of larvae changed under high versus low concentrations of conspecifics. We observed weak increases in vertical dispersion at higher concentrations both in newly hatched larvae and in postlarvae, but not in intermediate larval stages. We also tested for differences in horizontal swimming behaviour in high and low concentrations, by fitting a novel random walk model that allowed us to model both larval interactions and persistent turning behaviours. We showed substantial reduction in diffusive behaviour under high concentration conditions resulting from more frequent turns by each larva, but no evidence for consistent avoidance of conspecifics. Our study is the first to demonstrate concentration-dependent behaviours in lobster larvae.
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Maysaroh, Ummi, Edhi Martono e Tri Harjaka. "The Potency of Metarhizium anisopliae in Disturbing Oryctes rhinoceros (Coleoptera: Scarabaeidae) Growth and Development". Jurnal Perlindungan Tanaman Indonesia 26, n. 1 (11 luglio 2022): 51. http://dx.doi.org/10.22146/jpti.71755.
Testo completoAbstract (sommario):
Metarhizium anisopliae is one of the most frequently used insect pathogen fungi in controlling Oryctes rhinoceros. This research aims to learn the potency of fungus M. anisopliae against O. rhinoceros larvae growth and development at the laboratory. The research methods used are T-tests comprising seven treatments and three replications. Fungi were applied in all larvae instar stages starting from the pre-molting of the first larvae instar, post-molting of the second larvae instar, active second larvae instar, pre-molting of the second larvae instar, post-molting of the third larvae instar, active third larvae instar, and pre-pupae stage which were then compared with each instar’s own control. The result indicates that fungus M. anisopliae is capable of suppressing O. rhinoceros growth and development. The fungus induced highest mortality rate of 87% to the third instar larvae and lowest mortality rate of 27% to the pre-molting of the first instar larvae. The fungus also affected the duration of larval stage. At pre-molting of the third larvae instar treated with M. anisopliae, the larval duration was 40 days compared to that of control that took 135 days. At the post-molting of the third larvae instar, the larval duration was 25 days compared to that of control that took 120 days. At the third larvae instar, the larval duration was no more than 15 days compared to that of control that reached 110 days. At pre-pupal stage, the larvae only lasted for 6 days while at control, they were able to last for 15 days. The fungus also affected the success of larva development in becoming pupae in all O. rhinoceros larval stage. The lowest success rate was found in the post-molting of the third larvae instar treated with M. anisopliae with 7% compared to its control with 100% while the highest success rate was found in the pre-molting of the first larval instar with 47% compared to its control with 93%.
15
Dzepe, D., P. Nana, A. Fotso, T. Tchuinkam e R. Djouaka. "Influence of larval density, substrate moisture content and feedstock ratio on life history traits of black soldier fly larvae". Journal of Insects as Food and Feed 6, n. 2 (8 aprile 2020): 133–40. http://dx.doi.org/10.3920/jiff2019.0034.
Testo completoAbstract (sommario):
Performance and body composition of insect larvae depend on quality and quantity of their diet, and on biotic factors such as larval density. Experiments were undertaken to assess the effects of larval density, substrate moisture content and feedstock ratio on larval life history parameters of black soldier fly (BSF) in the laboratory. Four-day-old larvae were separately reared under six different densities (1, 2, 4, 6, 8 and 10 larvae/cm2) and at five substrate moisture content levels (40, 50, 60, 70 and 80%) obtained by moistening feed with fresh water. Five feedstock ratios of 25, 50, 100, 150 and 200 mg of feed per larva per day were also tested. Each treatment had four replicates and used commercial chicken feed as substrate. Results showed that individual larval feed reduction, wet weight, survival rate, body size and body thickness had a negative correlation with rearing densities, while larval development time correlated positively. The increase in substrate moisture content has significantly affected the larval feed reduction, wet weight, development time, body size and body thickness of the larvae. On the other hand, the survival rate was not significantly affected. The larvae subjected to diet 150 mg/larva/day showed a highest individual wet weight (0.19±0.003 g), body size (20.55±0.335 mm) and body thickness (4.982±0.081 mm). Their recorded development time was relatively short (11.25±0.500 days), compared to the other. The larval survival rate was not significantly affected by the feedstock ratio. This study indicates that larval life history parameters of BSF are influenced by the rearing conditions.
16
Melianawati, Regina, Ni Wayan Widya Astuti e Tridjoko Tridjoko. "Peranan Taurin pada Pertumbuhan dan Kelangsungan Hidup Larva Ikan Kerapu Bebek Cromileptes altivelis (Valenciennes, 1828)". Jurnal Kelautan Tropis 26, n. 1 (2 settembre 2022): 27–34. http://dx.doi.org/10.14710/jkt.v26i1.13490.
Testo completoAbstract (sommario):
Taurine is an important amino acid for the growth of marine fish larvae The humpback grouper (Cromileptes altivelis) is a highly valuable marine fish that has been farmed in hactheries. The increasing of larval growth and survival rate of humpback grouper was carried out by taurine addition as enrichment ingredient to zooplankton as live feed for larvae. The purpose of this study was to find out the role of taurine on larval growth and survival rate. Two treatments tested were taurine addition by bioencapsulated through zooplankton rotifers Brachionus rotundiformis (A) and without taurine addition in rotifers (B). The observed parameters were larval growth and survival rate. Larval samples were taken on day 1 and 5, then continued every 5 days until the end of the study, by using10 larval samples at each time. The results showed that mostly all larvae have already metamorphosed and become juveniles at 35 days old. At that time, larvae with taurine addition (A) have bigger in size, faster growth and also higher survival rate compared than larvae without taurine addition(B). Therefore, the result of this study indicated that the addition of taurine could improve larval growth and the survival rate of humpback grouper. Taurin merupakan asam amino penting untuk pertumbuhan larva ikan laut. Ikan kerapu bebek (Cromileptes altivelis) adalah salah satu jenis ikan laut bernilai ekonomis tinggi yang sudah dapat dibudidayakan. Peningkatan pertumbuhan dan kelangsungan hidup larva ikan kerapu bebek dilakukan dengan penambahan taurin sebagai bahan pengkaya ke dalam zooplankton sebagai pakan alami larva. Tujuan penelitian ini adalah mengetahui peranan taurin pada pertumbuhan dan kelangsungan hidup larva. Dua perlakuan yang diujikan adalah penambahan taurin melalui bioenkapsulasi pada zooplankton rotifer Brachionus rotundiformis (A) dan tanpa penambahan taurin pada rotifer (B). Parameter yang diamati adalah pertumbuhan dan kelangsungan hidup larva. Sampel larva diambil pada umur 1 dan 5 hari, selanjutnya setiap 5 hari sekali hingga akhir penelitian, dengan menggunakan 10 ekor larva setiap waktu pengambilan sampel. Hasil penelitian menunjukkan bahwa sebagian besar populasi larva telah bermetamorfosis menjadi juvenil pada umur 35 hari. Pada umur tersebut, larva yang diberi penambahan taurin (A) memiliki ukuran yang lebih besar, pertumbuhan yang lebih cepat dan tingkat kelangsungan hidup yang lebih tinggi dibandingkan dengan larva yang tidak diberi penambahan taurin (B). Oleh karenanya, hasil penelitian ini menunjukkan bahwa penambahan taurin pada rotifer dapat meningkatkan pertumbuhan dan kelangsungan hidup larva ikan kerapu bebek.
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Taira, K., V. Šnábel, N. Okada e Y. Saitoh. "Effect of low temperatures on the infectivity of Toxocara cati larvae parasitized in mouse tissues". Helminthologia 50, n. 2 (1 giugno 2013): 83–86. http://dx.doi.org/10.2478/s11687-013-0112-8.
Testo completoAbstract (sommario):
AbstractThe infectivity of Toxocara cati larvae in mouse tissues, following storage at 4 °C and −25 °C, was measured using a bioassay in mice. Tissues of donor mice infected with 30-day-old T. cati larvae were stored at 4 °C for 7 and 14 days, and at −25 °C for 24 hours, then tissue larvae were inoculated into recipient mice (n = 6/group). After 15 days, larval burden in recipient mice was assessed by digestion. In the control group, a mean of 42.0 % of the inoculated larvae were established in mice. Storage of tissues at 4 °C for 7 and 14 days did not affect larval infectivity; means of 43.5 % and 37.4 % of inoculated larvae, respectively, were established in mice. Larvae exposed to −25 °C for 24 hours did not establish in mice, except for one larva recovered from a single mouse. These results may support the potential of tissue larvae in livestock animals as a causative agent of human toxocarosis.
18
Smith, M. A. H., e R. J. Lamb. "Causes of variation in body size and consequences for the life history of Sitodiplosis mosellana". Canadian Entomologist 136, n. 6 (dicembre 2004): 839–50. http://dx.doi.org/10.4039/n03-122.
Testo completoAbstract (sommario):
AbstractThe body sizes of mature larvae and adults from field and laboratory populations of the wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), were measured to determine possible causes of variation in size and consequences of such variation through the life history. Mature larvae varied eightfold in mass. Female larvae were 80% heavier than males, on average. Variation in mass was associated with both the position of larvae on a wheat spike and the number feeding together on a developing seed. Larvae were 9% smaller when they developed on smaller, later developing seeds and 15%–18% smaller when they competed with five other larvae on an average-sized seed. Fewer small larvae survived winter. Larval density per infested seed increased with number of larvae per spike, suggesting that larval size may have density-dependent population effects. Small larvae produced few adults of Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae), an egg parasitoid that overwinters as a larva in the third larval instar of S. mosellana. These effects were probably due to size, but sex may also have been a factor. The size of adults, measured by wing and abdomen length, was also variable, although less so than the size of larvae. Adult size was not associated with time of emergence and both large and small females dispersed, but female fecundity (4–105 mature eggs per individual) increased with body size.
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Çelik, İhsan, e Pinar Çelik. "Larval Development of Penguin Tetra (Thayeria boehlkei): Morphological Observations". Journal of Agricultural Production 5, n. 2 (22 giugno 2024): 97–105. http://dx.doi.org/10.56430/japro.1464516.
Testo completoAbstract (sommario):
In this study, the larval development stage of the penguin tetra fish (Thayeria boehlkei), a popular species in the freshwater aquarium fish industry, was investigated. For this purpose, penguin tetra larvae were morphologically observed from time to hatching until they reached the juvenile stage. Throughout the larval development phase, samples were randomly taken daily and captured on a camera using a stereomicroscope. Larval development stages were categorized into four periods: (I) Yolk-sac larva, (II) Pre-flexion larva, (III) Flexion larva, and (IV) Post-flexion larva. Larvae were fed with Artemia nauplii until they reached the juvenile stage for the entire research. Morphological changes, including the state of the yolk sac from hatching, mouth opening, changes in body shape and color, and fin formation processes, were recorded daily. According to the findings, the mouth opened on the 5th day, and external feeding also started on the 5th and 6th days. At the same time, free swimming movements were observed in the larvae, and it was determined that the yolk sacs were consumed. The flexion larva stage occurred on the 15-16th days. The larval development process of the penguin tetra fish was completed within 25 days after hatching. After this stage, the juveniles became morphologically identical to their parents.
20
EKINGEN, PINAR, e NILGUN KAZANCI. "Larval description of Rhyacophila osellai Malicky, 1981 (Trichoptera: Rhyacophilidae) with some notes on its habitat". Zoosymposia 14, n. 1 (15 luglio 2019): 211–14. http://dx.doi.org/10.11646/zoosymposia.14.1.23.
Testo completoAbstract (sommario):
The unknown larva of Rhyacophila osellai Malicky, 1981 is described, and its diagnostic features illustrated. Mature pupae of R. osellai were identified from the male genitalia, and were associated with the larval stage by the metamorphotype method. Because larvae of caddisflies are used in biological monitoring studies, descriptions of unknown larvae are important to improve the knowledge of relationships between larvae and water quality.
21
TORII, TAKAAKI, e MASATOSHI NAKAMURA. "DNA identification and morphological description of the larva of Eoneureclipsis montanus (Trichoptera, Psychomyiidae)". Zoosymposia 10, n. 1 (9 agosto 2016): 424–31. http://dx.doi.org/10.11646/zoosymposia.10.1.39.
Testo completoAbstract (sommario):
Six genera of Psychomyiidae (Trichoptera) are known from Japan: Psychomyia, Tinodes, Lype, Metalype, Eoneureclipsis and Paduniella. A psychomyiid larva presumed to be Eoneureclipsis montanus was collected in Japan. We compared the COI sequence data of this putative E. montanus larva with those of identified adults to associate adult and larval life stages. Molecular evidence is presented to support the relationship between adults and larvae of E. montanus in Japan. Illustrations of E. montanus larval characters and a key and character matrix to genera of mature larvae of Japanese psychomyiids are provided.
22
Hare, James F. "Discrimination of nestmate larvae by the ant Leptothorax longispinosus". Canadian Journal of Zoology 74, n. 11 (1 novembre 1996): 2055–61. http://dx.doi.org/10.1139/z96-233.
Testo completoAbstract (sommario):
Laboratory colonies of the ant Leptothorax longispinosus were presented with 10 larvae each from their own nest, conspecific larvae from a nest collected from the same site of origin, and conspecific larvae from a nest collected from another site in the same geographical region. Workers preferentially retrieved larvae from their own nest over those from nests obtained at the same site and other sites. Non-nestmate larvae from the same site were not preferred over those originating from other collection sites. Thus, L. longispinosus workers discriminate among conspecific larvae and preferentially retrieve nestmate larvae. Results of experiments involving CO2-anaesthetized larvae or larva-sized silicone "baits" suggest that the discriminator substances underlying nestmate larva recognition are chemical in nature and are borne on the larval cuticle. Further, those chemical attractants are present on material found within the ant's nest. In a final series of experiments, nestmate larvae were placed in contact with non-nestmate conspecific larvae or with larvae of a congener (Leptothorax ambiguus). Again workers preferred nestmate larvae, and preferred conspecific over allospecific larvae. However, there was no evidence that contact with nestmate larvae enhanced the acceptance of either conspecific or allospecific larvae, nor that contact with non-nestmate larvae diminished the acceptability of actual nestmate larvae. These findings suggest that any cues transferred via contact are insufficient to overwhelm a larva's own underlying recognition signature or that workers selectively attend to familiar cues.
23
Fauzi Mansur, Fadlul Azim. "Cutaneous Larva Migrans on the Hand". Malaysian Journal of Science Health & Technology 7, n. 3 (1 settembre 2021): 57–59. http://dx.doi.org/10.33102/mjosht.v7i3.184.
Testo completoAbstract (sommario):
Cutaneous larva migrans results from infection by zoonotic nematode larvae, usually by animal hookworm larvae, and is a condition that is not uncommon in rural communities. The usual site of this lesion is on the feet, where larval penetration from soil takes place. Unusual sites such as the upper extremity and groin are very rare. We report a case of cutaneous larva migrans on the hand (unusual site) from Kelantan, Malaysia.
24
Ali, M. Ibrahim, S. Y. Young, G. W. Felton e D. A. Streett. "Influence of Cotton Plant Structures on Heliothine Larval Development and the Production and Infectivity of Occlusion Bodies of Nucleopolyhedrovirus in Larvae". Journal of Entomological Science 38, n. 3 (1 luglio 2003): 368–76. http://dx.doi.org/10.18474/0749-8004-38.3.368.
Testo completoAbstract (sommario):
Helicoverpa zea (Boddie) and Heliothis virescens (F.), reared on different cotton structures, were studied for larval growth and development, susceptibility to H. zea nucleopolyhedrovirus (HzNPV), and production of occluded virus (OBs). Larval weight of both species after 10 d of rearing differed with larvae on artificial diet having the highest weight and those on square bracts the lowest weight. In both species, pupal weight and length of pupal developmental period were positively correlated with the larval weight, but length of the larval developmental period was negatively correlated with larval weight. Mortality from virus infection of H. zea and H. virescens larvae on squares, square bracts or flowers did not differ significantly among the structures. In both species, the number of viral OBs produced was greater in larvae fed flowers than those fed other structures and was positively correlated with the weight gained by a healthy larva on that plant structure. The mean LC50 for OBs produced in H. zea or H. virescens larvae on square, square bract or flower did not differ significantly. These results indicate that dietary difference in fruiting structures of cotton plants directly affects H. zea and H. virescens larval growth and development and indirectly affects the production of virus by HzNPV-infected larvae.
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P.K. DALAL e RAMESH ARORA. "Impact of temperature on food consumption and nutritional indices of tomato fruit borer, Helicoverpa armigera (Hübner) (Noctuidae: Lepidoptera)". Journal of Agrometeorology 18, n. 1 (1 giugno 2016): 62–67. http://dx.doi.org/10.54386/jam.v18i1.901.
Testo completoAbstract (sommario):
Rising temperatures under changing climatic conditions results in the increase in food intake by the insect pests. The present studies on effect of different alternating temperatures on food consumption and nutritional indices of Helicoverpa armigera (Hübner) on tomato crop were conducted during 2013-14. The total food consumption by H. armigera larvae during total (third to fifth instar) larval duration increased from 2.457±0.048 g/larvae at 25:10oC to 3.545±0.021 g/larva at 30:16oC. This suggests that with increase in temperature there is increase in food consumption by H. armigera larvae. The share of food consumption by fifth instar larvae was e” 80 per cent of total food consumption by H. armigera larvae in all the treatments.Nutritional indices for total larval duration of H. armigera such as consumption Index (CI) rose from 0.929±0.020 at 25:10oC to 1.495±0.014 at 30:16oC, The relative growth rate (RGR) of total larval period varied from 0.139±0.002 at 25:10oC to 0.174±0.003 at 30:10oC. The rise in alternating temperature from 25:10oC to 30:10oC resulted in increased RGR of H. armigera larvae.
26
Sunaryo, Sunaryo, I. Nyoman Widiasa, Ali Djunaedi e Priyo Sasmoko. "Mortalitas Larva Litopenaeus vannamei Pada Penerapan Perbedaan Sistem Filtrasi Air Media Pemeliharaan". Jurnal Kelautan Tropis 21, n. 2 (7 dicembre 2018): 103. http://dx.doi.org/10.14710/jkt.v21i2.3089.
Testo completoAbstract (sommario):
Mortality of Litopenaeus vannamei larvae with the different filtration system of seawater as media for rearingMortality of Litopenaeus vannamei larvae in shrimp hatcheries centers is commonly high. Therefore, innovation to solve the problem through water quality management improvement in necessary by applying ultrafiltration system to shrimp hatchery. This experiment aims to determine larval mortality rate in response to the application of different filtration systems. Experiments were conducted using 4 milions larvae of L. vannamei shrimp. Shrimp larvae were kept in 4 tanks, each volume was 8 m3. Two reservoirs tank were equipped with ultrafiltration and other systems used sand-filter as controls. Implementation of experimental activities used action research method with two repetitions. Observation were conducted on mortality of shrimp larvae and water quality, i.e., temperature, salinity, pH, TSS, dissolved O2, NH3 and NO3-2. The result showed the shrimp larvae reared with the application of ultrafiltration system had significantly lower percentage of mortality (55,02 %) compared with filtering using sand-filter (59,58 %). Concentrations of Ammonia (NH3-N) and TSS content increased along with longer period of larval rearing.Mortalitas larva udang Litopenaeus vannamei di sentra pembenihan masih tinggi. Inovasi sistem pengendalian kualitas air pada media pembenihan udang perlu dilakukan. Percobaan dilakukan untuk mengetahui respon tingkat mortalitas larva Litopenaeus vannamei denan penerapan perbedaan sistim filtrasi. Pelaksanaan percobaan menggunakan metode action research dengan pengulangan 2 kali. Percobaan dilakukan dengan menggunakan larva Udang Litopenaeus vannamei stadia larva sebanyak 4 juta ekor. Larva Udang dipelihara dalam 4 buah bak. Dua buah bak dilengkapi dengan sistem ultrafiltrasi dan bak lainnya menggunakan sandfilter sebagai kontrol. Pengamatan dilakukan terhadap mortalitas larva udang, suhu, salinitas, pH, MPT, O2 terlarut, NH3 dan NO3-2. Hasil penelitian menunjukkan bahwa rata-rata mortalitas Larva udang Vannamei yang dipelihara dengan pola pemeliharaan dengan penerapan sistim ultrafiltrasi adalah 55.02% yang berbeda sangat nyata (p>0,01) dibandingkan dengan penerapan pola pemeliharaan menggunakan sandfilter yaitu 59,58% . Kualitas air media pemeliharaan larva udang Vannamei, terutama: kandungan Ammoniak (NH3-N) dan MPT menunjukkan semakin meningkat dengan semakin lamanya waktu pemeliharaan.
27
Einer, H., e E. Ellegård. "Nasal myiasis by Oestrus ovis second stage larva in an immunocompetent man: case report and literature review". Journal of Laryngology & Otology 125, n. 7 (24 maggio 2011): 745–46. http://dx.doi.org/10.1017/s002221511100096x.
Testo completoAbstract (sommario):
AbstractObjective:We report a case of an Oestrus ovis larva which developed into the second larval stage within a healthy, immunocompetent human, and we review the relevant literature.Methods:Clinical case report and Pubmed search of reports of human nasal myiasis due to Oestrus ovis, especially those describing the larval stage.Results:Humans are not normally hosts of the sheep nasal bot fly, but infestations by its larvae have been described. The eye is the most common site, but larvae have occasionally been found in the human nose. Transformation of larvae into the second and third stages, within the human nose, is even more uncommon.Conclusion:To the best of our knowledge, we report the first Swedish case, and the third case world-wide, of Oestrus ovis larval development beyond the first larval stage, within an immunocompetent, healthy human.
28
Clemen, Günter, e Hartmut Greven. "Long-term effects of arrested metamorphosis on dental systems in Salamandra salamandra (Salamandridae: Urodela)". Vertebrate Zoology 68, n. 2 (27 luglio 2018): 143–55. http://dx.doi.org/10.3897/vz.68.e31600.
Testo completoAbstract (sommario):
We describe the dental systems of six larvae of Salamandra salamandra hypophysectomized in 1976 under an earlier project to arrest metamorphosis. Larvae cover roughly three developmental stages from early (intrauterine) larval stage to early metamorphosis. Animals survived surgery and lived up to 16 months until fixation. One specimen was studied by histological serial sections. In the period until fixation larvae grew from approximately 3 cm to 7 cm in length (dependent on the developmental stage before surgery) retaining their larval appearance. Changes in the dental systems depended on the stage the larvae had reached before surgery. Generally, after surgery some traits had started or continued development, such as appearance of maxillae as well as resorption of the palatinal tooth patches and the coronoids in the youngest larva examined, whereas other traits had been largely retained and even continued to grow (e. g. larval dentate vomers). In three larvae, the anterior part of the palatines was covered by the posterior margin of the vomer giving the impression of a ‘vomeropterygopalatinum’, known from some newts as temporary fusion of vomer and palatine in consequence of a delayed metamorphosis. However, in the Salamandra-larvae both elements appeared to be connected syndesmotically rather than to be fused by bone tissue The oldest larva (metamorphic stage IV, approximately at the onset of metamorphosis), had lost the palatinal portion of pterygopalatina and had reduced the tooth patches of the vomers to a single row, but outgrowth of the vomerine bar had not taken place.
29
ARCHANGELSKY, MIGUEL, e MARIANO C. MICHAT. "Morphology and chaetotaxy of the larval stages of Andogyrus seriatopunctatus Régimbart (Coleoptera: Adephaga: Gyrinidae)". Zootaxa 1645, n. 1 (23 novembre 2007): 19–33. http://dx.doi.org/10.11646/zootaxa.1645.1.2.
Testo completoAbstract (sommario):
The larval stages of Andogyrus seriatopunctatus Régimbart are described and illustrated, including morphometric and chaetotaxic characters. A larval ground pattern for the chaetotaxic characters is presented; it is based on first instar larvae of A. seriatopunctatus. Unidentified larvae of Dineutus MacLeay and a third instar larva of Gyrinus argentinus Steinheil were also inspected. For chaetotaxic homologization comparisons with other adephagan families were performed, mainly with Carabidae and Dytiscidae. The ground pattern is considered provisional due to the lack of previous studies in this family. Larvae of A. seriatopunctatus are briefly compared to those of A. buqueti (Aubé). Notes on the biology of A. seriatopunctatus are also included.
30
Alzmann, Norbert, Bernd Köhler e Gerhard Maier. "Spatial Distribution, Food and Activity of Gomphus pulchellus SELYS 1840 (Insecta; Odonata; Gomphidae) from a Still Water Habitat". International Review of Hydrobiology 84, n. 3 (gennaio 1999): 299–313. http://dx.doi.org/10.1002/iroh.199900031.
Testo completoAbstract (sommario):
AbstractDistribution patterns of Gomphus pulchellus larvae in different sediments with different density of prey organisms were studied in the field in a small gravel pit lake in the south of Germany. Larval burrowing behaviour at different temperatures as well as food preference, consumption rates and activity were studied in laboratory experiments. In the study lake G. pulchellus larvae lived exclusively in places where macrophytes were present and in fine sediments (mean grain size <3 mm) with detritus cover. There was a significant positive correlation between larval density and density of food organisms suggesting that abundance of food is one of the determinants of larval distribution. In late autumn larvae migrated to deeper places probably to survive the winter. Low temperatures simulated in laboratory experiments did not induce larvae to burrow deeper. Larvae were always found in a sediment depth of 0.59–0.74 cm. Experiments with mixed prey showed that G. pulchellus larvae preferred tubificid worms and chironomid larvae over gammarids and ephemerid larvae. However, chironomid larvae which stayed in their tubes had a higher survival rate than those outside of tubes. Single‐prey experiments showed that G. pulchellus larvae can prey not only on benthic species but also on Daphnia from the open water. Functional‐response experiments showed that one G. pulchellus larva consumes a maximum of 2 to 3 tubificid worms or chironomid larvae per day, which corresponds to a maximum biomass (freshweight) of 5 to 30 mg per day. Video recordings of activity showed that G. pulchellus larvae cover long distances of up to 52 m per night on the substrate surface and that activity on the substrate surface started after midnight and ceased before sunrise. Consumption of Zooplankton prey and high activity above the substrate is interpreted as an adaptation of G. pulchellus larvae to the life in still water habitats.
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Prabowo, Heri, e I. G. A. A. Indrayani. "Keefektifan Nematoda Patogen Serangga Steinernema sp. Terhadap Achaea janata L., Serangga Pemakan Daun Jarak Kepyar (Ricinus communis)". Buletin Tanaman Tembakau, Serat & Minyak Industri 5, n. 2 (10 ottobre 2016): 58. http://dx.doi.org/10.21082/bultas.v5n2.2013.58-68.
Testo completoAbstract (sommario):
<p>Penggunaan pestisida kimia yang cukup tinggi pada akhir-akhir ini telah menimbulkan dampak negatif ter-hadap lingkungan, sehingga pengendalian hama yang ramah lingkungan sangat diperlukan. Saat ini, peng-gunaan nematoda entomopatogen terutama Steinernema sp., membuka peluang untuk digunakan sebagai pengendalian Achaea janata. Tujuan dari penelitian ini untuk mengetahui keefektifan Steinernema sp. ter-hadap A. Janata , dilaksanakan di laboratorium patologi serangga Balai Penelitan Tanaman Pemanis dan Serat pada bulan Maret sampai dengan Agustus 2011. Penelitian menggunakan rancanagan acak lengkap (RAL) dengan empat ulangan. Setiap ulangan menggunakan 25 larva A. janata instar 2. Larva diekspose de-ngan berbagai variasi konsentrasi Steinernema sp. dan kematian larva diamati setiap hari sampai 120 jam setelah infeksi. Konsentrasi Steinernema sp. yang digunakan adalah 0, 50, 100, 200, 300, dan 400 JI/larva. Hasil penelitian pemberian Steinernema sp. pada konsentrasi 200, 300, dan 400 JI/larva cukup efektif untuk membunuh A. janata dengan persentase berkisar antara 80–94% mulai 48–120 jam setelah perlakuan. Se-makin tinggi konsentrasi nematoda, semakin tinggi mortalitas A. janata. Steinernema sp. dengan konsen-trasi 400 JI/larva paling efektif membunuh larva, menurunkan bobot larva, bobot pupa, jumlah telur yang dihasilkan, dan fertilitas telur.</p><p> </p><p>High intensity of chemical pesticide application has become a serious concern of environmentalists in recent years, because of various negative impacts of it. Therefore, environmentally friendly techniques of controlling insect pest are needed. Recently, the use of entomopathogenic nematodes, especially Steinernema sp., has created new possibilities of promising control techniques against insect pests. The aim of this study was to evaluate the effectiveness of Steinernema sp. to A. janata larvae in laboratory. This research was conducted at the Laboratory of Insect Pathology Laboratory of Indonesian Sweetener and Fiber Crops Research Insti-tute from March to August 2011. Tests used the 2nd stage larvae of Achaea janata, the leaf eater of castor (Ricinus communis). Treatment arranged in a completely randomized design (CRD) with 4 replicates. For each test used 25 larvae which were exposed to various concentrations of Steinernema sp. Concentration of Steinernema sp. used was 0, 50, 100, 200, 300, and 400 infective juvenile/larvae. Daily mortality A. janata larvae, larval and pupal weight, the number of eggs laid, and number of hatch eggs were recorded. Steinernema sp. on concentration of 200; 300; and 400 IJ/larvae was effective to cause mortality of A. janata larvae (80–94% mortality after 48–120 hours). The higher the concentration of the nematode the higher larval mortality. Steinernema sp. with concentration of 400 IJ/ larvae was effective decreasing larval and pupal weight, the number of eggs laid, and fertility of the eggs produced.</p>
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PIETRYKOWSKA-TUDRUJ, EWA, e BERNARD STANIEC. "Comparative larval morphology of Platydracus and Staphylinus (Staphylinidae: Staphylinini: Staphylinina) with notes on their biology and redescription of the pupa of Staphylinus". Zootaxa 3580, n. 1 (11 dicembre 2012): 24. http://dx.doi.org/10.11646/zootaxa.3580.1.2.
Testo completoAbstract (sommario):
The mature larva of Platydracus latebricola (Gravenhorst, 1806) is described for the first time and the larva and pupa of Staphylinus erythropterus Linné, 1758 are redescribed. Illustrations of structural features are provided. The combination of characters that allow for distinguishing the known mature larvae of Platydracus, and larvae and pupae of Staphylinus from closely related genera within tribe Staphylinini are given. The mature larvae of Platydracus and Staphylinus are compared and the generic status of the former is confirmed. Life history data under laboratory conditions of S. erythropterus are provided. Two larval instars in this species, a state unique within the tribe Staphylinini was reported.
33
Melianawati, Regina, Ni Wayan Widya Astuti e Tridjoko. "PERTUMBUHAN LARVA DAN PRODUKSI BENIH IKAN KERAPU BEBEK Cromileptes altivelis Valenciennes, 1828 HASIL BUDIDAYA TURUNAN KE-3". Jurnal Ilmu dan Teknologi Kelautan Tropis 10, n. 3 (1 dicembre 2018): 589–600. http://dx.doi.org/10.29244/jitkt.v10i3.20322.
Testo completoAbstract (sommario):
ABSTRAKKetersediaan induk dalam suatu usaha pembenihan memiliki peran yang sangat penting. Namun demikian, ketersediaan induk yang berasal dari alam sangat terbatas jumlahnya, sehingga perlu dilakukan penyediaan calon induk yang berasal dari hasil budidaya. Ikan kerapu bebek Cromileptes altivelis Valenciennes, 1828 turunan pertama (F-1) dan turunan kedua (F-2) sudah dapat diproduksi dari hasil budidaya, namun benih turunan ketiga (F-3) belum dapat diperoleh. Penelitian ini bertujuan untuk mendapatkan karakteristik morfologis dan pertumbuhan larva ikan kerapu bebek F-3 sebagai calon induk F-3, serta tingkat keberhasilan produksi benihnya. Pemeliharaan larva dilakukan dalam hatchery hingga larva menjadi benih. Parameter yang diamati meliputi panjang total dan panjang duri sirip larva, berat tubuh larva serta sintasan dan jumlah produksi benih. Hasil penelitian menunjukkan bahwa panjang total larva umur 5, 15, 25 dan 35 hari, masing-masing adalah 3,20±0,07; 4,42±1,11; 8,35±1,12 dan 12,51±3,23 mm. Duri sirip mulai terukur pada larva umur 15 hari. Berat larva umur 30 hari adalah 0,11±0,04 g. Pola pertumbuhan panjang total dan berat tubuh larva adalah eksponensial, sedangkan pola pertumbuhan duri siripnya adalah linier. Masa pemeliharaan larva hingga menjadi benih adalah ± 40 hari. Jumlah benih ikan kerapu bebek F-3 yang diproduksi dalam satu kali siklus pemeliharaan berkisar 440 hingga 2.300 ekor dari 50 ekor induk dan 3 kali siklus pemijahan dengan tingkat kelangsungan hidup 1,30% hingga 8,80%. Hasil penelitian ini mengindikasikan bahwa ikan kerapu bebek F-3 dapat diproduksi dari hasil budidaya seperti halnya pada F-1 dan F-2. ABSTRACTBroodstocks are the most important part of humpback grouper culture, but their availability in nature are limited. Therefore, it is necessary to produce broodstock candidates from culture. The first (F-1) and the second (F-2) generation of humpback grouper have already been produced but the third generation (F-3) production is still on the way. This study was conducted to find out morphological characteristic of the third generation (F-3) of humpback grouper larvae as the candidate of the third generation of broodstock, larval growth and the success rate of seed production. Larvae rearing was done in hatchery until larvae metamorphosed to be seeds. Observed variables including larval total length and spine length, larval body weight, survival rate and the juvenile productions. The study result showed the total length of 5, 15, 25 and 35 days old larvae were 3.20±0.07; 4.42±1.11; 8.35±1.12 and 12.51±3.23 mm, respectively. The spine began measured on 15 days old larvae. The body weight of 30 days old larvae was 0.11±0.04 g. The growth pattern of larval total length and body weight were exponential, while the growth of spine was linear. Rearing period from larvae to juveniles was 40 days. Number of F-3 seed production of humpback grouper produced from once rearing cycle range between 440 and 2,300 fish and the survival rate range from 1.30% up to 8.80%. Therefore, this study could indicate that seed of F-3 humpback grouper can be produced as those of F-1 and F-2.
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Salam, Md Abdus, Shishir Biswas, Md Sazzad Hossain, Nur-A. Sultana e Md Jasim Uddin. "Temporal changes in glochidia larval occurrence and condition index in freshwater mussels, Lamellidens marginalis (Lamarck, 1819) collected from a wetland of Bangladesh". Journal of Fisheries 12, n. 2 (25 luglio 2024): 122203. http://dx.doi.org/10.17017/j.fish.684.
Testo completoAbstract (sommario):
Information on glochidia larval occurrence and release time from the brooding mussels are crucial for the development of larval rearing system or commercial collection of juveniles from the wilds. We report monthly changes in glochidia larval occurrence and condition index (CI) in freshwater mussel, Lamellidens marginalis, collected from a wetland in Bangladesh. Specimens were drawn monthly over a year from October 2021 to September 2022. Lamellidens marginalis females displayed glochidia larvae in the supra-branchial chamber over ten months from March to December. No glochidia larva was reported in females during January and February when the water temperature remained below 18°C. All females carried glochidia larvae during March and April, indicating no larval shedding at this time. The percentage of females containing glochidia larvae dropped suddenly in May (22.22%), suggesting that glochidial release from the gill chamber to the environment was initiated by May. Larval presence in only some females (22% to 86%) at each sampling date from May to September implied an extended glochidial discharge period till September when the water temperature was above 24°C. The CIs varied from 0.36 to 0.79, with two distinct peaks in December and March when all females carried glochidia larvae. In conclusion, monthly changes in larval occurrence and discharge could be primarily related to temperature and the existence of larvae in mussels could affect the CIs in L. marginalis.
35
Ediriweera, ERHSS. "Evaluation of Anthelmintic properties of Sesbania grandiflora Pers. (Kathurumurunga) against larvae of Toxocara canis and Haemonchus contortus – In Vitro Study". Healer 2, n. 1 (3 febbraio 2021): 42–47. http://dx.doi.org/10.51649/healer.15.
Testo completoAbstract (sommario):
Sesbania grandiflora is a slender tree. It is a common garden plant in Sri Lanka, which grows well in mid and low country. In Sri Lanka, Sesbania grandiflora is used as a home remedy, in treatment of worm infections in humans. Toxocara canis is a helminth parasite infecting dogs and other canids. It also causes toxocariasis in humans. Haemonchus contortus is a nematode that infects goats and causes anaemia, marked reduction in growth and reproduction, and even death. Using this information, in vitro larvae migratory inhibition assay was carried out on Toxocara canis and Haemonchus contortus larve. This study revealed 98.1% and 94.3% larvae migration inhibition with larvae of Toxocara canis and Haemonchus contortus respectively. Least number of migrated larvae was observed in the positive control Levamisole and all the larvae were dead after migration. In decoction of S.grandiflora, all the migrated Toxocara larvae were dead and Haemonchus larvae were dead or in Grade1 (inactive but occasional movement can be observed) condition. Inhibition of Toxocara larval migration and Haemonchus larval migration with decoction of Sesbania grandiflora and Levamisole are statically significant (p < 0.05). Since mean of LMI (larval migration inhibition) of Levamisole is greater than mean of LMI of Sesbania grandiflora with both larvae, Levamisole is more effective than Sesbania grandiflora. Based on these findings, the aqueous extract of leaves of Sesbania grandiflora is shows a statistically significant anthelmintic activity in in-vitro model.
36
Chynoweth, R. J., J. W. M. Marris, K. F. Armstrong, A. Chomic, J. Linton e R. B. Chapman. "Predation by Ostenia robusta on Costelytra zealandica pupae". New Zealand Plant Protection 66 (8 gennaio 2013): 157–61. http://dx.doi.org/10.30843/nzpp.2013.66.5582.
Testo completoAbstract (sommario):
Soil sampling in a cereal crop near Southbridge Canterbury revealed dipteran larvae attacking Costelytra zealandica (White) pupae Approximately 50 of the pupae had larvae associated with them DNA sequencing analysis of larval specimens indicated they most likely belonged to the family Dolichopodidae Larval specimens were reared through to adults and were identified as Ostenia robusta (Hutton) (Diptera Dolichopodidae) This is the first record of the association of O robusta larvae with C zealandica pupae A general description of the adult and larva of this species is provided along with DNA sequencing data and observations on its association with C zealandica pupae The potential role of O robusta in regulating populations of C zealandica is briefly considered
37
Chen, Shicheng, Michael G. Kaufman, Michelle L. Korir e Edward D. Walker. "Ingestibility, Digestibility, and Engineered Biological Control Potential of Flavobacteriumhibernum, Isolated from Larval Mosquito Habitats". Applied and Environmental Microbiology 80, n. 3 (2 dicembre 2013): 1150–58. http://dx.doi.org/10.1128/aem.03319-13.
Testo completoAbstract (sommario):
ABSTRACTFlavobacteriumhibernum, isolated from larval habitats of the eastern tree hole mosquito,A. triseriatus, remained suspended in the larval feeding zone much longer (8 days) than other bacteria. Autofluorescent protein markers were developed for the labeling ofF. hibernumwith a strong flavobacterial expression system. Green fluorescent protein (GFP)-taggedF. hibernumcells were quickly consumed by larval mosquitoes at an ingestion rate of 9.5 × 104/larva/h. The ingestedF. hibernumcells were observed mostly in the foregut and midgut and rarely in the hindgut, suggesting that cells were digested and did not pass the gut viably. The NanoLuc luciferase reporter system was validated for quantitative larval ingestion rate and bacterial fate analyses. Larvae digested 1.87 × 105cells/larva/h, and fewF. hibernumcells were excreted intact. Expression of the GFP::Cry11A fusion protein with the P20 chaperone protein fromBacillus thuringiensisH-14 was successfully achieved inF. hibernum. Whole-cell bioassays of recombinantF. hibernumexhibited high larvicidal activity againstA. triseriatusin microplates and in microcosms simulating tree holes.F. hibernumcells persisted in microcosms at 100, 59, 30, and 10% of the initial densities at days 1, 2, 3, and 6, respectively, when larvae were absent, while larvae consumed nearly all of theF. hibernumcells within 3 days of their addition to microcosms.
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RONDEROS, MARÍA M., CARLA G. CAZORLA e GUSTAVO R. SPINELLI. "The immature stages of the biting midge Culicoides debilipalpis Lutz (Diptera: Ceratopogonidae)". Zootaxa 2716, n. 1 (22 gennaio 2019): 42. http://dx.doi.org/10.11646/zootaxa.2716.1.3.
Testo completoAbstract (sommario):
The fourth instar larva and pupa of Culicoides debilipalpis Lutz, 1913 are described, illustrated, and photomicrographed from material collected in tree-holes of Salix sp. in Entre Rios Province, Argentina by using binocular, phase-contrast, and scanning electron microscopy. Measurements of instars I–IV are also presented. The larva shows features typical to carnivorous-predatory larvae, as well as characters typical of larvae occurring in tree holes and clean water. Details on larval biology, habitat, and feeding behavior are given.
39
Xu, Jiajun, Zelin Feng, Jian Tang, Shuhua Liu, Zhiping Ding, Jun Lyu, Qing Yao e Baojun Yang. "Improved Random Forest for the Automatic Identification of Spodoptera frugiperda Larval Instar Stages". Agriculture 12, n. 11 (15 novembre 2022): 1919. http://dx.doi.org/10.3390/agriculture12111919.
Testo completoAbstract (sommario):
Spodoptera frugiperda (fall armyworm, FAW) is a global agriculture pest. Adults have a strong migratory ability and larvae feed on the host stalks, which pose a serious threat for maize and other crops. Identification and counting of different instar larvae in the fields is important for effective pest management and forecasting emergence and migration time of adults. Usually, the technicians identify the larval instars according to the larva morphological features with the naked eye or stereoscope in the lab. The manual identification method is complex, professional and inefficient. In order to intelligently, quickly and accurately identify the larval instar, we design a portable image acquisition device using a mobile phone with a macro lens and collect 1st-6th instar larval images. The YOLOv4 detection method and improved MRES-UNet++ segmentation methods are used to locate the larvae and segment the background. The larval length and head capsule width are automatically measured by some graphics algorithms, and the larval image features are extracted by SIFT descriptors. The random forest model improved by Boruta feature selection and grid search method is used to identify the larval instars of FAWs. The test results show that high-definition images can be easily collected by using the portable device (Shenzhen, China). The MRES-UNet++ segmentation method can accurately segment the larvae from the background. The average measurement error of the head capsule width and body length of moth larvae is less than 5%, and the overall identification accuracy of 1st–6th instar larvae reached 92.22%. Our method provides a convenient, intelligent and accurate tool for technicians to identify the larval instars of FAWs.
40
Webb, C. M. "Post-Larval Development of the Tellinacean Bivalves Abra Alba, Tellina Fabula and Donax Vittatus (Mollusca: Bivalvia), With Reference to the Late Larva". Journal of the Marine Biological Association of the United Kingdom 66, n. 3 (agosto 1986): 749–62. http://dx.doi.org/10.1017/s0025315400042338.
Testo completoAbstract (sommario):
The post-larval shell and hinge development of the bivalves Abra alba (Wood), Tellina fabula Gmelin and Donax vittatus (da Costa) from the recently metamorphosed size to a juvenile size of 1·2–1·4 mm shell length has been examined using scanning electron microscopy. Early post-larval development in the stages up to 1·0–1·2 mm size can involve considerable morphogenetic change and requires careful description with photographic developmental series. The form of the pediveliger larva is present in the early post-larval shell and confirms the identity of the larvae of A. alba and T. fabula. The veliger and pediveliger larvae of A. alba are described. The similar larval form of the tellinacean bivalves is modified by differential margin growth early in post-larval development. Comparison of these bivalves with allied species reveals that the post-larvae are distinguishable at even the smallest sizes by the shell and hinge form. The metamorphic size of A. alba ranges from 0·26 to 0·31 mm, of T. fabula from 0·25 to 0·28 mm and of D. vittatus from 0·25 to 0·35 mm. The bivalve post-larvae were collected from the shallow sublittoral of Oxwich Bay, Bristol Channel, U.K., and the larvae from the overlying waters, during the years 1980–2.
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Mulyana, Jeane Siswitasari, Achmad Farajallah e Yusli Wardiatno. "Redescription of Larval Development in Cultured Pearl Oyster Pinctada maxima". ILMU KELAUTAN: Indonesian Journal of Marine Sciences 23, n. 2 (21 giugno 2018): 109. http://dx.doi.org/10.14710/ik.ijms.23.2.109-112.
Testo completoAbstract (sommario):
Larval development plays a major role in efficient pearl culture. The cultured larvae will be later used for recipient and donor oysters in cultured pearl production. Larval developmental stage of silver lip pearl oyster Pinctada maxima has been reported by several studies. Those studies used female and male oyster parents directly taken from natural habitat.This study aimed to redescribe larval development of P. maxima from commercial pearl oyster culture farm in Indonesia. Larval development of this species whose parents are originated from selected groups in the pearl culture farm has not been reported yet, thus it is necessary to be described. This species undergoes specific larval developmental stage. The larvae were observed under microscope, and then the average shell length (SL) and shell height (SH) were measured. D-shaped veliger larva (77.4±0.3 µm SL; 65.4±1.1 µm SH) appeared 20 h after fertilization. Tenday-old larva (156.2±2.8 µm SL; 149.5±5.6 µm SH) had developed umbo region so it was called umbonal larva. Umbonal larva then developed further into plantigrade larva (411.3±9.8 µm SL; 380.5±6.9 µm SH) in 25 days after fertilization. Developmental stage and larval sizein P. maxima is similar with those observed in P. fucata and P. margaritifera. Keywords: growth, larva, plantigrade, shell, umbo, veliger
42
Widiastuti, Zeny, Fahruddin Fahruddin e I. Gusti Ngurah Permana. "PENGARUH PENGAYAAN Artemia sp. DENGAN SUMBER DHA YANG BERBEDA TERHADAP SINTASAN LARVA LOBSTER PASIR (Panulirus homarus)". Media Akuakultur 16, n. 1 (3 luglio 2021): 21. http://dx.doi.org/10.15578/ma.16.1.2021.21-31.
Testo completoAbstract (sommario):
Kegiatan pembenihan lobster masih dikembangkan di Indonesia. Sintasan yang rendah dan pakan yang sesuai masih menjadi masalah utama dalam kegiatan pembenihan lobster. Artemia sebagai pakan utama diduga belum mencukupi kebutuhan nutrisi larva lobster. Upaya pemberian bahan pengaya sebagai alternatif untuk meningkatkan nutrisi diharapkan dapat meningkatkan sintasan larva lobster. Pemberian bahan pengaya yang mengandung asam lemak dokosa heksanoid acid (DHA) ke Artemia dianggap penting bagi pertumbuhan dan sintasan pada krustasea. Tujuan penelitian ini untuk mengetahui performa larva lobster berdasarkan tingkat sintasan maupun perkembangan larva dengan pemberian pakan artemia yang diperkaya dengan DHA. Perlakuan yang diberikan meliputi Artemia yang baru menetas (A), Artemia yang diperkaya dengan plankton Isochrysis galbana strain Tahiti konsentrasi (1-1,5 x 106 sel/mL) (B), DHA selco dosis 0,6 g/L (C), dan Artemia inkubasi 18 jam tanpa pengayaan (D). Pemeliharaan larva dilakukan pada bak 100 L dengan sistem air stagnan. Perkembangan larva yang mampu dicapai pada semua perlakuan adalah stadia-IIIa. Pemberian Artemia yang diperkaya dengan DHA selco menunjukkan hasil sintasan yang lebih baik pada pemeliharaan enam hari pertama namun tidak memberikan pengaruh yang signifikan. Pada masa pemeliharaan sampai 20 hari terjadi penurunan sintasan (SR) mencapai hanya 1%. Hal ini disebabkan adanya bakteri dan protozoa seperti jenis protozoa Zoothamnium sp. dan bakteri berfilamen teramati menempel pada tubuh larva sehingga mengganggu pergerakan dan kemampuan larva dalam menangkap mangsa. Berdasarkan penelitian ini maka penggunaan pakan Artemia yang diperkaya DHA Selco dapat menjadi alternatif pakan larva lobster namun tetap diperlukan kontrol kualitas air yang baik.Efforts to culture spiny lobster, Panulirus homarus larvae are still being developed in Indonesia. One of the main challenges in lobster hatcheries is to find an appropriate feed and improving larval survival. Artemia has been used as the main feed and considered to have insufficient nutritional ingredient for lobster larvae. Enrichment of feed to improve its nutrient contents is expected to increase the larval survival. DHA-enriched feed is considered essential for growth and survival of crustaceans. The aim of this study was to determine the survival and development of larvae fed with DHA-enriched Artemia. The treatments consisted of newly hatched Artemia (A), enriched Artemia with phytoplankton, Isochrysis galbana strain Tahiti at a density of 1-1.5 x 106 cells/mL (B), enriched Artemia with DHA selco at a dose of 0.6 g/L (C), and Artemia incubated for 18 hours without DHA enrichment (D). Each Artemia enrichment was performed for 18 hours. Larval rearing was carried out in a 00 L tank with static water system. The achieved larval developmental stage in all treatments was stage-IIIa. Administration of enriched Artemia with DHA selco showed a better larval survival during the first six days of larval rearing. But, it did not give any significant effect. The survival was then decreased to only 1% on day-20. This was due to the presence of bacteria and protozoa which decreased water quality. Protozoa Zoothamnium sp. and filamentous bacteria were observed attaching to the body of the larvae, disrupting the movement and ability of larvae in capturing prey. Based on this research, the use of Artemia enriched with DHA selco as an alternative for lobster larvae feed, but better water quality control is still needed.
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Bennett, P., e J. Vanstaden. "Gall Formation in Crofton Weed, Eupatorium adenophorum Spreng (syn Ageratina adenophora), by the Eupatorium Gall Fly Procecidochares utilis Stone (Diptera, Trypetidae)". Australian Journal of Botany 34, n. 4 (1986): 473. http://dx.doi.org/10.1071/bt9860473.
Testo completoAbstract (sommario):
Procecidochares utilis lays eggs on the stem apex of Eupatoriurn adenophorurn and on hatching the larvae tunnel into the stem. In response to the presence of the larvae a gall forms in the stem which may contain from 1 to 23 larvae. Callus tissue differentiates and divides to block the entry passages and seal the larvae in the stem. The normal development of the stem is halted and it swells as the pith cells continue to divide and become gall parenchyma. A layer of highly meristematic nutritive tissue develops around the larval cavity on which the growing larvae feed. New vascular tissue differentiates in the pith region of the gall around the larval cavity. Growth of the gall ceases when the larvae pupate, by which time most of the nutritive tissue has been consumed and the cells in the pith region have enlarged. Just prior to pupation the mature larva cuts a cylindrical tunnel to the edge of the gall, leaving only the epidermis intact; it then returns to the central cavity to pupate. The adult fly escapes by breaking through the epidermal 'window' at the end of the cylindrical tunnel.
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Winch, Judith M., e J. Riley. "Studies on the behaviour, and development in fish, ofSubtriquetra subtriquetra: a uniquely free-living pentastomid larva from a crocodilian". Parasitology 93, n. 1 (agosto 1986): 81–98. http://dx.doi.org/10.1017/s0031182000049842.
Testo completoAbstract (sommario):
SUMMARYThe primary larva of the porocephalid pentastomidSubtriquetra subtriquetra, which infects the nasopharynx ofCaiman sclerops, is uniquely free-living. Eggs hatch within the nasal passages and the emergent larvae can remain infective to the fish intermediate host for 4–5 days. During this period larvae exhibit very stereotyped behaviour, alternating between a characteristic stationary ‘fishing’ posture and very brief periods of movement. Larval activity increases significantly at 3 days, probably effecting dispersal to a more favourable site for host invasion. Host location is passive and invading larvae penetrate to the swim-bladder where subsequent larval development, which involves 7 moults, occurs. All 8 larval stages are freely mobile in the swim-bladder and possess hooks. Sensilla, disposed in characteristic patterns, are present throughout development, increasing in number to the infective stage; the majority of sensilla are located on sensory papillae.
45
MOORE, WENDY, e ANDREA DI GIULIO. "Description and behaviour of Goniotropis kuntzeni larvae (Coleoptera: Carabidae: Paussinae: Ozaenini) and a key to genera of Paussinae larvae". Zootaxa 1111, n. 1 (20 gennaio 2006): 1. http://dx.doi.org/10.11646/zootaxa.1111.1.1.
Testo completoAbstract (sommario):
Goniotropis species are large, parallel-sided paussine beetles common in the New World tropics and ranging from southern Arizona to northern Argentina. Specimens of Goniotropis kuntzeni Bänninger were collected in southern Arizona and larvae were reared under laboratory conditions. The egg, first instar larva and second instar larva are described and illustrated, providing the first larval description for this genus. Goniotropis larvae live in burrows that they construct and seal with their terminal disk (which is composed of modified urogomphi and dorsal plates). They feed by trapping live insect prey with the moveable components of their terminal disk, and then they bring the captured prey into their gallery to consume. Burrowing and feeding behaviours of Goniotropis kuntzeni larva closely resemble those previously described for Pachyteles species. A key to the genera of paussine larvae is provided.
46
AYÓN-PARENTE, MANUEL, e MICHEL E. HENDRICKX. "First zoeal stage of the hermit crab Enallopaguropsis guatemoci (Glassell, 1937) (Crustacea: Anomura: Paguroidea: Paguridea) obtained in the laboratory". Zootaxa 4227, n. 3 (3 febbraio 2017): 359. http://dx.doi.org/10.11646/zootaxa.4227.3.4.
Testo completoAbstract (sommario):
The first larval stage of Enallopaguropsis guatemoci is described in detail and illustrated. The larva is compared with larvae known for other genera of Paguridae except Pagurus. A synthesis of all characters provided herein indicates that first larvae of E. guatemoci can be separated from all known pagurid larvae (except Pagurus) by the combination of the following characters: carapace with long dorsal carina, posterolateral spines absent; abdominal somites 3–5 with pair of moderately long spines; telson narrowly triangular, not forked; spine at antennal protopod as long as endopod.
47
Walker, Edward D., Richard W. Merritt, Michael G. Kaufman, Matthew P. Ayres e Mark H. Riedel. "Effects of variation in quality of leaf detritus on growth of the eastern tree-hole mosquito, Aedes triseriatus (Diptera: Culicidae)". Canadian Journal of Zoology 75, n. 5 (1 maggio 1997): 706–18. http://dx.doi.org/10.1139/z97-091.
Testo completoAbstract (sommario):
Growth of larvae of the eastern tree-hole mosquito, Aedes triseriatus (Say), measured as survival to adulthood, development time, and body mass at adult emergence, was significantly better when larvae were provided with fresh rather than senescent beech leaves as food substrate. Leaf type affected larval growth performance independently of ration of leaf available per larva when the ration level was high and larvae were not densely crowded, but leaf type and ration level had interactive effects on larval growth performance when ration was more limiting and larvae denser. Fresh leaves contained about twice as much nitrogen, had a lower carbon:nitrogen ratio, leached more mass into water, and contained significantly more soluble protein and carbohydrate than did senescent leaves. Thus, the observed growth responses could be explained on the basis of variation in nutrient content of, and greater leaching from, the fresh leaves. Larval growth was also significantly better on intact senescent beech leaves than on leaves that had been leached to remove soluble protein and carbohydrate; it was also significantly better on leaves whose surfaces had flourishing bacterial growth than on leaves with disinfected surfaces. Growth of female larvae fit well a pupation window model where larvae attained a minimum mass to emergence past a minimum development time across a range of leaf substrates varying in quality and quantity.
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Puspasari, Reny, Ario Damar, M. Muklis Kamal, DTF Lumban Batu, Ngurah Nyoman Wiadnyana e M. Taufik. "DINAMIKA LARVA IKAN SEBAGAI DASAR OPSI PENGELOLAAN SUMBER DAYA IKAN DI LAGUNA PULAU PARI KEPULAUAN SERIBU". Jurnal Kebijakan Perikanan Indonesia 5, n. 1 (31 maggio 2013): 1. http://dx.doi.org/10.15578/jkpi.5.1.2013.1-7.
Testo completoAbstract (sommario):
Proses rekruitmen populasi ikan sangat ditentukan oleh kelangsungan hidup larva ikan yang ada di daerah pemijahan/asuhan. Laguna Pulau Pari merupakan daerah pemjahan bagi banyak jenis larva ikan karang. Tujuan dari penelitian ini adalah untuk mengkaji dinamika kelimpahan dan komposisi dari larva ikan di laguna Pulau Pari. Hasil penelitian menunjukkan bahwa kelimpahan larva ikan yang ditemukan berkisar antara 1,0 x103 – 14,7 x 103 individu/m3. Puncak kelimpahan tertinggi terjadi pada bulan Juli dan Oktober. Larva ikan ditemukan tersebar di semua lokasi pengamatan. Larva pada fase perkembangan pre flexion ditemukan dalam presentase yang paling tinggi. Selama masa pengamatan ditemukan 79 famili larva ikan yang didominasi oleh Pomacentridae, Aulostomidae, Blenniidae, Engraulidae dan Pinguipedidae. Dinamika yang terjadi pada larva ikan dapat dijadikan dasar bagi pengelolaan perikanan di wilayah Laguna Pulau Pari dengan cara memperluas daerah perlindungan laut dan rehabilitasi ekosistem Laguna Pulau Pari, sehingga peran dan fungsinya sebagai pemasok rekrut bagi stok ikan di perairan sekitarnya terjaga. Fish Recruitment is, in turn, thought to be directly related to the survival of the early life stages in the spawning/nursery ground. Pulau Pari Laguna is considered as a spawning ground for many reef fishes. The aims of the research were to investigate the dynamic of abundance and composition of fish larvae in Pulau Pari lagune. The Results show, fish larvae abundance range between 1,0 x 103 – 14,7 x 103 ind/m3. Highest larval abundance occurred on July and October, which predicted as the month of fish larvae production seasons. Fish larvae were distributed in all part of the lagune. Larvae in the pre flexion stage found in the highest precentation compare to other. Totally 79 families of reef fish larvae were found during June – November 2010 dominated by Pomacentridae, Aulostomidae, Blenniidae, Engraulidae and Pinguipedidae.
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Marini, Marini, Vivin Mahdalena e Tanwirotun Ni'mah. "Potensi Ekstrak Daun Marigold (Tagetes erecta L.) sebagai Larvasida terhadap Larva Aedes aegypti di Laboratorium". Jurnal Vektor Penyakit 12, n. 2 (17 dicembre 2018): 109–14. http://dx.doi.org/10.22435/vektorp.v12i2.898.
Testo completoAbstract (sommario):
Abstract
Control of mosquito vectors by using natural ingredients is being developed intensively. Marigold (Tagetes erecta) was widely used as a mosquito repellent plant. The results of research before had found that marigold leaf extract has a repulsive effect on Aedes aegypti mosquitoes. This study aimed to identify the potential of marigold leaf extract as larvacide against Ae. aegypti larvae in the laboratory. The material used in this research was extracts of marigold leaves. Larvacide test was carried out by dissolving of extract in water at the concentration of 2,000 ppm, 4,000 ppm, 6,000 ppm, 8,000 ppm, and 10,000 ppm. The larvae used was Ae. aegypti larvae as many as 25 larvae each five treatment of replications. Probit analysis was conducted on larval mortality after 24 hours of exposure. The results of the probit analysis showed that the estimated concentration of extracts that could result in larval mortality up to 95% (LC95) was 7,456 ppm. From the result we can conclude that ethanol extract of marigold leaves (T. erecta L. ) has the biolarvacidal activity against larvae.
Abstrak
Pengendalian vektor nyamuk dengan memanfaatkan bahan alam makin banyak dikembangkan. Marigold (T. erecta) merupakan tumbuhan yang banyak dimanfaatkan sebagai tanaman pengusir nyamuk. Hasil penelitian sebelumnya menemukan bahwa ekstrak daun memiliki daya tolak terhadap nyamuk Ae. aegypti. Penelitian ini bertujuan untuk melihat potensi ekstrak daun marigold sebagai larvasida terhadap larva Ae. aegypti instar III di laboratorium. Bahan yang digunakan pada penelitian ini adalah ekstrak etanol daun marigold hasil ekstraksi dari penelitian sebelumnya. Uji larvasida dilakukan dengan melarutkan ekstrak dalam air pada konsentrasi 2.000 ppm, 4.000 ppm, 6.000 ppm, 8.000 ppm, dan 10.000 ppm. Larva yang digunakan yaitu larva Ae. aegypti sebanyak 25 larva tiap perlakuan dengan lima ulangan. Dilakukan analisis probit terhadap kematian larva setelah 24 jam paparan. Hasil analisa probit menunjukkan perkiraan konsentrasi ekstrak yang mampu mengakibatkan kematian larva hingga 95% (LC95 ) adalah 7.456 ppm. Ekstrak etanol daun marigold (T.erecta L.) memiliki potensi sebagai biolarvasida terhadap larva Ae. aegypti.
50
Putri, Mentari Permana, Gita Dwi Prasasty, Chairil Anwar, Dwi Handayani e Dalilah Dalilah. "Water PH Correlates With The Number of Mosquito Larvae in Nature Tourism Park". Journal of Agromedicine and Medical Sciences 9, n. 1 (28 febbraio 2023): 36. http://dx.doi.org/10.19184/ams.v9i1.37116.
Testo completoAbstract (sommario):
Mosquitoes go through four development phases: egg, larva, pupa and adult. The growth, survival, and adaptation of mosquito larvae are strongly influenced by the physical and chemical characteristics of the waters. Nature tourism parks have ecological and environmental potential for the development and spread of mosquitoes and vector diseases. This study aims to look at the correlation of the physical and chemical elements of water to the number of mosquito larvae. The study design was cross-sectional analytic observational. In TWA, 57 containers were found with 10 indoor and 47 outdoor locations. The container contains water with a salinity of 0-0.3, pH 4.5-8.3, TDS 3-899 ppm, and a temperature of 26 - 34℃. A total of 423 mosquito larvae consisting of Culex and Aedes species. Ae. albopictus is the dominant larval species found. Based on the Spearman test, there was no significant correlation between temperature, total dissolved solids and salinity with the number of mosquito larvae (p>0.05), while PH was positively correlated with the number of mosquito larvae (p = 0.019).
Keywords: Chemical, Physical, Water, Mosquito larva