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1
Rouil, Jeff. "Évolution et dynamique du système di-symbiotique chez les pucerons du genre Cinara". Electronic Thesis or Diss., Montpellier, SupAgro, 2023. http://www.theses.fr/2023NSAM0004.
Abstract (sommario):
Des systèmes pluri-symbiotiques ont été mis en évidence chez plusieurs espèces de pucerons (Hemiptera : Aphididae) et plus particulièrement chez les espèces du genre Cinara. La caractérisation taxonomique des symbiontes présents chez une soixantaine d'espèces de Cinara a permis de déterminer que Serratia symbiotica est la bactérie la plus fréquemment retrouvée comme symbionte secondaire obligatoire. De plus, la reconstruction de l'histoire évolutive des associations symbiotiques chez Cinara semble indiquer une acquisition ancestrale de Serratia symbiotica comme co-symbionte obligatoire, même si la présence d'autres bactéries chez certaines espèces indique que des évènements de remplacement ont eu lieu. L''analyse des génomes de souches de Serratia symbiotica ont montré que ces symbiontes possèdent des caractéristiques génomiques différentes et des variations de leur forme et de leur localisation dans des bactériocytes. Ces données semblent montrer un gradient de modifications dans le passage d'une bactérie facultative à une bactérie endosymbionte fixée sur lequel se trouve l'ensemble des co-symbiontes obligatoires des Cinara. Au cours de cette thèse, à l'aide d'approches de phylogénomique, nous avons décrit l'histoire évolutive de Serratia symbiotica et mis en évidence de multiples acquisitions indépendantes de cette bactérie comme co-symbionte obligatoire des Cinara. Ces transitions d'un mode de vie facultatif à obligatoire sont associées à des réductions de génome et de taux de G-C plus ou moins importantes selon les lignées, révélant l'ancienneté relative de l'association. Parmi les évènements d'acquisitions, nous avons montré que l'un d'entre eux avait conduit à une co-spéciation durant environ 20Ma des trois partenaires de la symbiose nutritionnelle (Cinara, Buchnera et Serratia). Dans ce clade, nous avons observé des structures cellulaires et des caractéristiques génomiques stables pour les deux co-symbiontes. De plus, l'analyse des taux de substitutions de chacun des partenaires a permis de décrire pour la première fois une évolution parallèle entre les deux symbiontes et leur hôte. L'analyse détaillée de la composition en gènes des bactéries co-symbiotiques de ce clade a mis en évidence une complémentation forte pour la production des nutriments nécessaires à l'hôte. De plus, l'analyse de l'ensemble de leurs gènes a révélé qu'une forte sélection purifiante s'exerce sur eux. Dans une autre partie, une approche expérimentale de quantification des symbiontes au cours de développement sur trois espèces de Cinara suggère une différence de capacité de régulation du co-symbionte Serratia. Cette différence est observée entre deux espèces de Cinara pour lesquelles les Serratia sont issues d'acquisition indépendantes et dans lesquelles sa localisation est différente. Finalement, une analyse de comparaison génomique sur des phages APSE (bactériophage intégré) présents dans les co-symbiontes de Cinara et procurant une défense contre les parasitoïdes a permis de décrire la diversité des APSE et de l'évolution de leur génome chez les pucerons. Cette analyse a aussi montré que les éléments mobiles pourraient jouer un rôle dans l'acquisition de nouveaux gènes dans la cassette de la toxine défensive. L'ensemble de ces travaux révèle un système pluri-symbiotique dynamique dans lequel le nouveau partenaire bactérien est régulièrement remplacé au cours de l'évolutionThe existence of multi-symbiotic systems has been demonstrated in several aphid species (Hemiptera: Aphididae) and more particularly in species of the genus Cinara. The taxonomic caracterisation of the symbionts present in about sixty species of Cinara has made it possible to determine that Serratia symbiotica is the most frequently found bacterium as an obligatory secondary symbiont. Furthermore, the reconstruction of the evolutionary history of symbiotic associations in Cinara species suggests an ancestral acquisition of Serratia symbiotica as an obligate co-symbiont, although the presence of other bacteria in some species indicates that replacement events have occurred. More recently, genome analysis of Serratia symbiotica strains associated have shown that these symbionts exhibit different genomic characteristics ranging and variations in their shape and localisation in bacteriocytes. These data seem to show a gradient of changes in the transition from a facultative life-style to obligate endosymbiont in which we observe all of the (now obligate) co-symbionts of Cinara. During this phd, using phylogenomics, we inferred the evolutionary history of Serratia symbiotica within Cinara and highlighted multiple independent acquisitions of this bacterium as a co-obligate symbiont of Cinara. These transitions from facultative to obligate life-style are associated with genome reductions and low G-C content that are more or less important depending on the lineage, revealing the relative age of the symbiotic association with Serratia. Among the inferred acquisition events, one in particular led to co-speciation over about 20 Ma of the three partners of the nutritional symbiosis (Cinara, Buchnera and Serratia). In this clade, we observed stable cellular and genomic structures with highly reduced genomes and low G-C content for both co-symbionts. Furthermore, the analysis of the substitution rates of each partner allowed us to describe for the first time a parallel evolution between the two symbionts and their host. Further analysis of the gene composition of the co-symbiotic bacteria in this clade revealed strong complementation for the production of nutrients required by the host. Furthermore, the analysis of their set of genes revealed that they are under strong purifying selection. In addition an experimental approach aimed at quantifying the symbionts during development on three Cinara species suggest that aphid species differ in their capacity to regulate the co-symbiont Serratia. This difference is observed between two Cinara species for which the Serratia originated from independent acquisitions and in which its localisation is different. Finally, a genomic comparison analysis on APSE phages (integrated bacteriophage) present in Cinara co-symbionts and providing defence against parasitoids allowed a description the diversity of APSEs and their genome evolution in aphids. This analysis also showed that mobile elements could play a role in the acquisition of new genes in the defensive toxin cassette. Altogether, this study reveals a dynamic multi-partner endosymbiosis where the new partner is recurrently replace
2
GUO, JING QUAN. "Transmission par pucerons des luteovirus de la jaunisse nanisante de l'orge (jno) : de l'etude de l'interaction virus-aphide a l'estimation du risque epidemique". Paris 11, 1995. http://www.theses.fr/1995PA112453.
Abstract (sommario):
Le present travail a pour objet l'etude de l'interaction virus-aphide afin de mieux apprecier le lien entre puceron porteur (virulifere) et la transmission des virus (pav, mav, rpv) de la jno. Les outils mis au point nous permettent de preciser le comportement de differentes biotypes et especes d'aphides vis-a-vis de ces virus et l'analyse des donnees fournies par les tours agraphid et les pots pieges ; elements actuels d'estimation du risque jno en europe. La methode immuno-pcr a ete adaptee pour amplifier les 3 luteovirus dans les pucerons. La sensibilite de cette rt-pcr permet de detecter le pav dans l'extrait d'un puceron de r. Padi dilue 128 fois. Ces luteovirus peuvent etre detectes par immuno-pcr dans l'hemolymphe de 3 especes vectrices et 4 especes non-vectrices. Ces resultats montrent que la paroi intestinale de ces pucerons ne constitue pas une barriere selective. Lors de l'analyse de transmission sequentielle, le devenir quantitatif et qualitatif des virus chez les pucerons a ete etudie par elisa ameliore et immuno-pcr. Dans la plupart des cas, la concentration virale decroit suivant trois phases. Ce schema s'applique aussi bien pour les pucerons vecteurs que pour les pucerons non-vecteurs. Cependant la reduction de la concentration virale chez les pucerons est associee a la baisse de l'efficacite vectrice. On constate des variations biotypiques dans l'efficacite vectrice chez r. Padi et s. Avenae. Une faible efficacite des biotypes rp-ch et sa-v a transmettre leur virus specifique est associee a une diminution plus rapide de la concentration virale chez les pucerons. Cependant, chez un autre biotype (sa-r5), sa faible efficience n'est pas reliee a une reduction de la concentration virale. Les variations biotypiques observees peuvent donc etre liees a deux etapes de cycle du virus: (1) installation des virions dans la cavite generale ; (2) transfert des virions dans les gsa. On observe que la proportion des ailes viruliferes (determines par immuno-pcr ou elisa) captures par le piege a succion est nettement correlee avec les niveaux d'infection des pots pieges en region parisienne durant les automnes 1992-1994. Bien qu'il existe des variants de capacite vectrice chez r. Padi, la detection par immuno-pcr des ailes viruliferes de cette espece peut etre utilisee pour determiner la taille de l'inoculum primaire
3
Moores, Graham David. "Biochemistry of resistance in Myzus persicae and Aphis gossypii". Thesis, University of Bedfordshire, 1997. http://hdl.handle.net/10547/621850.
Abstract (sommario):
The insecticide resistance mechanisms present in the aphids Myzus persicae and Aphis gossypii have been characterised and sensitive biochemical assays have been developed to monitor their presence in individual aphids. It was found that enhanced esterase activity is present in both aphid species, and that this enhanced activity results from the presence of larger amounts of the same enzyme rather than the presence of a more efficient enzyme. In Myzus persicae this mechanism alone is sufficient to confer high levels of insecticide resistance. In Aphis gossypii, it appears that the presence of insensitive acetylcholinesterase (AChE) is necessary for measurable levels of resistance to occur. During the course of this work, insensitive AChE was detected in Myzus persicae for the first time. This additional resistance mechanism, when combined with the enhanced esterase activity, was found to confer extremely high levels of tolerance against specific insecticides. This additional mechanism is rare in the UK at present but the use of sensitive assays to monitor its existence is of increasing importance. When the AChE mechanism becomes more prevalent in the UK, as it almost certainly will, new strategies for aphid control will be needed. Further examples of insensitive AChE conferring insensitivity not only to carbamates, but also to organophosphates, have also been detected in Aphis gossypii. The inter-relationships of the two mechanisms in this species have been resolved and new monitoring methods made available.
4
Stewart, Ashley. "Molecular interactions among soybean aphids and aphid-resistant soybean". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574777162373585.
5
Wadleigh, Richard Walter. "Reduced oxidative metabolism as a resistance mechanism in parathion-resistant strains of the green peach aphid, Myzus persicae (Sulz.) (Aphidae: Hemiptera) from Ohio /". The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487262513410293.
6
Hopkins, Graham Wyn. "Rarity of tree aphids with particular reference to the birch aphid Monaphis antennata (Kaltenbach)". Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338048.
7
Blande, James D. "Differential signalling from specialist and generalist Brassica feeding aphids to differentially adapted aphid parasitoids". Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402402.
8
Peng, Zhongkui. "Feeding determinants in aphids with special reference to the Rose Aphid Macrosiphum rosae (L.)". Title page, table of contents and introduction only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09php398.pdf.
Abstract (sommario):
Bibliography: leaves 170-189. This thesis looks at aphid feeding determinants by type and location. It examines the role of leaf surface chemicals in the discrimination of host plants and the deterrent effect of catechin and its oxidative condensation products.
9
Tosh, Colin Robert. "Host plant specialisation in the black bean aphid, Aphis fabae". Thesis, University of York, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298436.
10
Diaz-Montano, John. "Components of soybean resistance to the soybean aphid, Aphis glycines Matsumura". Thesis, Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/185.
11
Burdick, Steven Curtis. "Interactions between Ultraviolet Light and Soybean Aphid, Aphis Glycines Matsumura (Hemiptera: Aphididae)". Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/27225.
Abstract (sommario):
Global increases in ultraviolet (UV) radiation have led to greater interest in its current and potential effects on organisms, including insects and plants. Here we report the short-term effects of UV on soybean aphids (Aphis glycines Matsumura), a common phytophagous pest of soybeans. We examined how modified amounts of UV radiation affect soybean aphids by focusing on changes in 1) soybean aphid densities and 2) within plant distribution. In a laboratory experiment artificially adding UV decreased soybean densities compared to a low UV control. In a field experiment blocking UV had minimal effects on soybean aphid densities. Further observations suggest that soybean aphid location could mediate UV effects; the soybean leaf may shield aphids from some direct harmful effects of UV. Our results demonstrate the potential importance of UV to insect herbivores and how insect behavior may mitigate negative effects.
12
Webster, Ben. "Olfactory basis of host-recognition in the black bean aphid, Aphis fabae". Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/5272.
Abstract (sommario):
Behavioural and electrophysiological responses of winged virginoparous Aphis fabae to volatile compounds of faba bean, Vicia faba, were studied and semiochemicals used in host location identified. In olfactometer bioassays, aphids responded positively to V. faba volatiles from an intact plant. This response also occurred when volatiles from an air entrainment sample of a V. faba plant were tested. Coupled gas chromatography-electroantennography revealed the presence of 16 electrophysiologically active volatile compounds in the air entrainment sample and 15 of these were identified as (E)-2-hexenal, (Z)-3-hexen-1-ol, 1-hexanol, benzaldehyde, 6-methyl-5-hepten-2-one, octanal, (Z)-3-hexen-1-yl acetate, (R)-linalool, methyl salicylate, decanal, undecanal, (E)-caryophyllene, (E)-β-farnesene, (S)-germacrene D, and (E,E,)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. A synthetic blend consisting of all identified compounds in the same concentration and ratio as in the air entrainment sample elicited a similar behavioural response from the aphids as the air entrainment sample. Each compound was tested for behavioural activity individually at the same concentration as in the air entrainment sample and subsequently over a range of different doses. It was found that the response to the complete blend was not due to a response to a single compound. Dose response experiments also revealed ten of the compounds elicited negative behavioural responses from aphids. Further behavioural experiments revealed that these responses were context-specific and behavioural activity of individual compounds was different when they were presented alongside other compounds in the blend. It was hypothesised that a blend of host volatiles in a species-specific ratio may be used by A. fabae to recognise its host. To determine whether or not ratios of volatiles could provide a reliable cue to host seeking aphids, intra-specific and diurnal variation of ratios of volatiles emitted were investigated. Although considerable variation in ratios was observed the quantities of some pairs of compounds were positively correlated, indicating a degree of consistency in the ratios.
13
Saheed, Sefiu Adekilekun. "Plant aphid interactions : effects of diuraphis noxia and rhopalosiphum padi on the structure and function of the transport systems of leaves of wheat and barley". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1003794.
Abstract (sommario):
The infestation of the cultivated grain crops by phloem feeding aphids has generated a great deal of interest over the years, due to the serious damage they cause to the crops and yield losses that result. The mechanism of the interaction between aphids and host plants remains largely unknown in spite of efforts to understand the basis of aphid feeding on grain crops. Greater efforts are required to explain the mechanism(s) of this interaction in order to achieve sustainable agriculture. This thesis focused on an investigation of the mechanism of feeding by the Russian wheat aphid, Diuraphis noxia Mordvilko (RWA) and the bird cherry-oat aphid, Rhopalosiphum padi L. (BCA) on barley and wheat cultivars. These two aphids co-occur naturally, but they inflict very different feeding effects on host plants. Structural and functional approaches were employed to investigate their feeding habits and these were then related to the observed differences in their host plants. Transmission electron microscopy (TEM) techniques were used to study the ultrastructural damage, while fluorescence microscopy techniques – using aniline blue fluorochrome (a specific stain for callose) and 5, 6-CFDA (a phloem-mobile fluorophore) – were employed to investigate the functional response to damage via wound callose formation and phloem transport capacity respectively. RT-PCR and quantitative real-time RT-PCR techniques were used to investigate the regulation of the genes involved in callose synthesis and degradation at the transcriptional level. Morphological observation of the damage caused by the aphids show that infestation by RWA results in extensive leaf chlorosis, necrosis and rolling, while infestation by BCA does not lead to any observable symptoms within the same period. Interestingly, the population study shows that BCA breeds faster than RWA within the two-week experimental period. The ultrastructural study of feeding damage caused by the two aphids on the vascular bundles of susceptible barley cv Clipper, shows a different patterns of damage. Probing the vascular bundles results in the puncturing of vascular parenchyma by both aphids, but severe damage occurs in sieve tubes-companion cell complex during sustained feeding by RWA. In contrast, less damage occurs when BCA feeds on the phloem. Drinking from the xylem by RWA results in deposition of a large quantity of electron-dense watery saliva, which apparently seals the xylem vessels completely, by blocking all the pit membrane fields between the xylem vessels and associated parenchyma cells. In contrast, drinking from xylem by BCA results in deposition of a dense, granular saliva into the xylem vessels only, which does not appear to totally occlude the pit membrane fields. This is the first known report in which ultrastructural evidence of aphids’ drinking in xylem is provided. The comparative effects of RWA feeding on a susceptible Betta and resistant Betta-Dn1 wheat cultivars showed that after two weeks, the Betta cultivar expressed damage symptoms such as chlorosis, necrosis and leaf roll, while few chlorotic patches and necrotic spots occur in resistant Betta-Dn1 cultivars. An ultrastructural investigation of the feeding damage caused to all leaf tissues revealed, for the first time, that RWA is capable of both intra- and inter-cellular probing within mesophyll cells. Probing in the mesophyll cells induces a more severe damage in susceptible Betta than in the resistant Betta-Dn1 counterpart. Similar differences in damage occurred during feeding in the thin-walled sieve tubes of the phloem, with the sieve tubes of the Betta showing more damage than that of the resistant Betta-Dn1. However, drinking from xylem resulted in the characteristic occlusion of metaxylem vessels by copious deposition of saliva by RWA in both Betta and Betta-Dn1 cultivars. In all cases of probing, feeding, and drinking by RWA in both cultivars, all probed cells with evidence of salivary material deposit and those cells adjacent to salivary material deposit, exhibit significant damage in susceptible Betta cultivar, whereas similar cells in Betta-Dn1 cultivars do not show as damage as severe. Investigation of the functional response of the plants to feeding by aphids through the deposition of wound-induced callose shows that formation and deposition of wound callose occurs in both longitudinal and cross veins within 24h of feeding by RWA. This deposition increases through short-term feeding (72h) and prolonged feeding (14d). This is in sharp contrast to the observations with BCA feeding,where little or no callose formation occurs within the same time frame. Callose formation and deposition occurs only when a higher population of BCA feeds on barley leaves. This is the first report of aphid-induced wound callose by BCA. In all cases of callose deposition, aphid stylet tracks were associated with callose and the deposition of callose appears to be a permanent feature, because wound callose remained in the leaf tissues even after 120h of the aphids’ removal. Wound callose signals (defence and anti-defence) are discovered to be transported in the phloem tissues and are dependent on the direction of assimilate flow. Examination of the possible regulation of wound callose genes at the transcriptional level shows that the two expressed glucan synthase gene sequences (GSL – genes involved in callose formation) analysed did not show any significant increase or regulation upon aphid infestation. Contrary to expectation, all three aphid-induced β-1, 3-glucanases (genes which are thought to be involved in callose degradation) showed higher expression in RWA-infested tissue than in BCA-infested tissue. The results of the feeding damage on the transport capacity of the phloem shows that BCA infestation does not lead to a significant reduction in the phloem transport capacity during short-term feeding (72h), while RWA-infested leaves showed considerable reduction in the transport capacity of the phloem within the same period. However, prolonged feeding (14d) by BCA induces a considerable reduction on the transport capacity of the phloem on the infested tissues. In contrast, a marked reduction in the transport capacity of the phloem occurs in RWA-infested leaves and in most cases, complete cessation of transport ensues. In conclusion, these data collectively suggest that RWA is a serious and most destructive phloem feeder in comparison to the BCA. RWA causes severe damage to all cellular tissues of the host plants, which result in apoplasmic and symplasmic isolation of xylem and phloem tissues, while BCA infestation does not result in such isolation within the same time and population levels. Resistance genes appear to function by conferring resistance to cell damage on the resistant cultivars during aphid feeding. Responses by plants to aphid infestation via wound callose deposition are again shown to be species-specific. A quick response results when RWA feeds, even at a very low population level, while a response occurs only at a higher infestation level by BCA, and this response was shown as not regulated at the transcriptional level. Differences in the damage to leaf tissues and wound callose deposition eventually lead to varying degrees of damage to the transport capacity of the phloem. These differences in the damage signatures are hereby suggested to be the cause of the diversity in the observed damage symptoms and the yield losses upon infestation by the two aphid species.
14
Laubscher, Jacobus Martin. "The effect of aphid lethal paralysis virus (ALPV) on the biology of grain aphids in the Western Cape". Doctoral thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/21980.
Abstract (sommario):
Aphid lethal paralysis virus (ALPV) could be detected by indirect immunofluorescent technique in dissected aphids. This technique was found to be more sensitive when compared to DAS-ELISA. The choice of a sensitive, low cost .detection method was of importance to test for low levels of virus in infected aphid body tissues where inapparent infection could cause detection problems. ALPV was visualized in ultrathin sections of diseased aphid body tissues by immunocytochemistry utilizing immunogold label. ALPV antigen was detected in the ovariole tissue, tracheocytes, symbionts of the mycetocytes, fat body cells, brain tissue, nerve tissue and stomach epithelial tissue. Virions were detected predominantly in the cytoplasm but were also found in the nucleus. ALPV antigen was not detected in muscle fibres or mitochondria. ALPV and Rhopalosiphum padi virus (RhPV) are transmitted transovarially. Different incidences of transmissions of ALPV were obtained for R. padi (2996) and Sitobion avenae (1696) and ALPV infections dramatically reduced the longevity and fecundity of these aphids. Infected apterous R. padi aphids were more fecund than alate aphids of the same clone. The percentage of viral infections in different aphid species (R. padi, S. avenae and Diuraphis noxia) was positively associated with temperature; higher temperatures dramatically increased the incidence of ALPV and RhPV and vice versa. The influence of ALPV on a natural R. padi aphid population was found to reduce the population size by 4996. This reduction coincided with a high death factor (70) of aphids per plant. A dramatic decline in R. padi aphid numbers and a high incidence of ALPV present in this aphid population was experienced. Parasitic fungal infections peaked at a later stage than ALPV, and a level of 21 parasitized aphids per plant was reached during this period. This appears to indicate that the presence of ALPV contributes to limit population development in R. padi aphids. Similar results were obtained with S. avenae aphids. Based on this data, ALPV could be considered as a major growth limiting factor in the development of small grain aphid populations in the western Cape. If the presence of the virus is taken into consideration, it could influence pest management strategies directly.
15
Chandler, Simon Michael. "Molecular studies of symbiotic proteobacteria in the black bean aphid (Aphis fabae Scopoli)". Thesis, University of York, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428528.
16
Hamid, Mohd Norowi Bin. "Effect of predators on population dynamics of green peach aphid on flue-cured tobacco in Virginia". Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/53128.
Abstract (sommario):
The effects of indigenous predators on green peach aphid (GPA), Myzus persicae (Sulzer), populations on flue-cured tobacco were evaluated in 1985 and 1986. The most common GPA predators found on tobacco were convergent lady beetle (CLB) (Hippodamia convergens), syrphid flies, Geocoris spp., Jalysus wackhimi, Nabis spp., Chrysopa spp., Micromus sp., and several other species coccinellids. However, CLB was the only predator that had a numerical response to increasing GPA density on tobacco. In the laboratory, the minimum number of GPA required to initiate reproduction in CLB, and the conversion rates were two factors that determined the oviposition rate of CLB. In fields, CLB demonstrated a sigmoid curve predator-prey relationship. CLB did not show a linear relationship until GPA populations reached a certain density. Furthermore, CLB did not show a response when GPA density was above the satiation point.
Although CLB were able to reduce GPA population growth, they were not able to maintain GPA populations below the economic injury level. Two factors probably limited the success of CLB to control GPA populations on flue-cured tobacco: 1.) the glandular trichomes of tobacco which produced gummy exudates, and 2.) the satiation point of CLB when GPA populations were very high. In addition, interplanting tobacco with clover increased the number of syrphid fly larvae on tobacco. Likewise, tobacco interplanted with sunflowers had increased big-eyed bug, populations, and tobacco-alfalfa and tobacco-tobacco plots had higher stilt bug populations on tobacco.Master of Science
17
Jimoh, Mahboob Adekilekun. "Comparative study of the feeding damage caused by the South African biotypes of the Russian wheat aphid (Diuraphis noxia Kurdjumov) on resistant and non-resistant lines of barley (Hordeum vulgare L.)". Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1003770.
Abstract (sommario):
Cereal crop productivity is hampered when these plants are infested by phloem feeding aphids. A great deal of research has been carried out with the direct aim of a clearer understanding of the mechanism involved in the interaction between aphids and their host plants. Research has directly or indirectly been geared towards enhanced plant productivity and achieving sustainable agriculture. Barley (Hordeum vulgare L.) is an important small grain crop in South Africa, whose crop performance is negatively affected by fluctuations in weather patterns as well as by agricultural pests. One of the insect pests infesting barley is the Russian wheat aphid, Diuraphis noxia Kurdjumov (RWA), of which the two South African biotypes, codenamed RWASA1 and RWASA2, were studied in this thesis. During dry spells, RWA infestation becomes a more serious threat to barley productivity. Resistant plants have been used to combat RWA infestation of small grains. In South Africa, 27 RWA-resistant wheat cultivars are currently used in commercial cultivation, but no resistant barley lines have, unfortunately, been developed, in spite of this grain’s significant economic importance. This informed the study in this thesis, and this interest particularly focussed on three RWA-resistant lines developed by the USDA, testing their performance against South African RWA biotypes, for possible adaptation to South Africa. The aim was thus to examine the plant-aphid interactions, aphid breeding rates, plant damage and sustainability, evidence of resistance or tolerance and finally potential performance under elevated CO2 (a very real climate change threat). Two major avenues of research were undertaken. The first aspect involved examination of structural and functional damage caused by RWASA1 and RWASA2 on the three resistant and a non-resistant line. Aphid population growth and damage symptoms (chlorosis and leaf roll) of infestation by these aphid biotypes were evaluated. This was followed by a structural and functional approach in which the effects of feeding on the transport systems (phloem and xylem) of barley were investigated. Fluorescence microscopy techniques (using aniline blue fluorochrome, a specific stain for callose and 5,6-CFDA, a phloem-mobile probe) were applied to investigate the feeding-related damage caused by the aphids, through an examination of wound callose formation and related to this, the resultant reduction in phloem transport capacity. Transmission electron microscopy (TEM) techniques provided evidence of the extent of the feeding-related cell damage. The second aspect involved a study of the effect of changing CO2 concentrations ([CO2]) on the resistant and susceptible barley cultivars to feeding by the two RWA biotypes. Leaves of plants grown at ambient and two elevated levels of [CO2] were analysed to investigate the effect of changing [CO2] on biomass, leaf nitrogen content and C:N ratio of control (uninfested) and infested plants. The population growth studies showed that the populations of the two RWA biotypes as well as bird cherry-oat aphid (BCA, Rhopalosiphum padi L.) increased substantially on the four barley lines. BCA was included here, as it had been the subject of several previous studies. RWASA2 bred faster than RWASA1 on all lines. The breeding rates of the two RWA biotypes were both suppressed and at near-equivalent levels on the three resistant lines, compared to the non-resistant PUMA. This suggests that the resistant lines possessed an antibiosis resistance mechanism against the feeding aphids. Feeding by the aphids manifested in morphological damage symptoms of chlorosis and leaf roll. The two biotypes inflicted severe chlorosis and leaf roll on the non-resistant PUMA. In the resistant plants, leaf rolling was more severe because of RWASA2 feeding compared to RWASA1 feeding. In contrast, chlorosis symptoms were more severe during RWASA1 feeding than was the case with RWASA2 feeding. Investigation of the effect of aphid feeding on the plants showed that callose was deposited within 24h and that this increased with longer feeding exposure. Wound callose distribution is more extensive in the non-resistant PUMA than in the resistant plants. RWASA2 feeding on the resistant lines caused deposition of more callose than was evident with RWASA1 feeding. During long-term feeding, it was evident that variation in the intensity and amount of wound callose was visible in the longitudinal and transverse veins of the resistant plants. Of the three STARS plants, STARS-9301B had the least callose. Interestingly, wound callose occurred in both resistant and non-resistant plants, in sharp contrast to what has been reported on resistant wheat cultivars that were developed in South Africa. The relative reduction in the wound callose deposited in the resistant line, when compared to the non-resistant lines, suggests the presence of a mechanism in the resistant lines, which may prevent excessive callose formation. Alternatively, the mechanism may stimulate callose breakdown. RWASA2 feeding on the resistant lines deposited more wound callose than RWASA1 feeding. This evidence supports the hypothesis that RWASA2 is a resistance breaking and more aggressive feeder than RWASA1 is; and further underscores the urgent need for development of RWA-resistant barley cultivars. The ultrastructural investigation of the feeding damage showed that the two biotypes caused extensive vascular damage in non-resistant plants. There was extensive and severe cell disruption and often obliteration of cell structure of the vascular parenchyma, xylem and phloem elements. In sharp contrast, among the resistant plants, feeding-related cell damage appeared to be substantially reduced compared to the non-resistant PUMA. Low frequency of damaged cells indicated that majority of the cell components of the vascular tissues were intact and presumed functional. There was evidence of salivary material lining the secondary walls of the vascular tissue, which resulted in severe damage. Within xylem vessels, saliva material impregnated half-bordered pit pairs between the vessels and adjacent xylem parenchyma. This is believed to prevent solute exchange through this interface, thereby inducing leaf stress and vi leaf roll. A notable finding is that RWASA2 effectively induced more cell damage to vascular tissues in the resistant lines than did RWASA1. In general the experimental evidence (see Chapter 5) suggests that the resistant lines are possibly more tolerant (or able to cope with) to RWA feeding. Evidence for this is the reduction of wound callose and at the TEM level, a comparatively less obvious cell damage in the resistant lines, which suggests that they possess antibiosis and tolerance capacity. The apparent reduction of feeding-related cell damage from the TEM study confirmed the disruptive action of the feeding aphids in experiments using the phloem-mobile probe, 5,6-CF. Results showed that feeding by RWASA1 and RWASA2 reducedthe transport functionality of the phloem in all cases, but that RWASA2 feeding caused a more obvious reduction in the rate and distance that 5,6-carboxyfluorescein was transported, than did RWASA1. Investigation of the effect of changing [CO2] on the barley cultivars showed that in the absence of aphids and under elevated CO2 conditions, the plants grew more vigorously. In this series of experiments, the infested plants suffered significant reduction in biomass under ambient (as was expected) and under the two elevated CO2 regimes. Biomass loss was greater at elevated CO2 than under ambient [CO2]. The infested nonresistant PUMA plants showed a more significant biomass loss than did the resistant cultivars. Clearly, the benefits derived from elevated CO2 enrichment was thus redirected to the now-advantaged aphids. Uninfested vii plants showed an increase in leaf nitrogen under the experimental conditions. However, feeding aphids depleted leaf nitrogen content and this was more apparent on plants exposed to RWASA2 than was the case with RWASA1. The end result of this was that C:N ratio of infested plants were higher than uninfested plants. Clearly, the faster breeding rates of the aphids at elevated CO2 caused depletion of N and a resultant deficiency exacerbated chlorosis as well as leaf rolling due to the higher aphid population density under elevated CO2 than at ambient. By 28 days after infestation (DAI), majority of the plants exposed to enriched CO2 treatments had died. A major finding here was thus that although this study demonstrated that elevated CO2 resulted in an increase in biomass, this was detrimentally offset in plants infested by the aphids, with a decline in biomass and loss of functionality leading to plant death at 28DAI. The overriding conclusion from this study is a clear signal that the twin effects of CO2 enrichment (a feature of current climate change) and aphid infestations may precipitate potential grain shortages. A disastrous food security threat looms.
18
Ohnesorg, Wayne J. "Non-target effects of soybean aphid, Aphis glycinces Matsumura (Hemiptera: Aphididae), management in Iowa". [Ames, Iowa : Iowa State University], 2008.
19
Brunner, Samantha Marie. "Impact of Nitrogen and Rhizobial Seed Inoculants on Soybean Aphid (Aphis Glycines Matsumura) Densities". Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26560.
Abstract (sommario):
Soybeans are able to obtain nitrogen from two different sources, nitrogen found in the soil (e.g. from fertilizers) and biologically fixed nitrogen (from symbiotic bacteria called rhizobia). Nitrogen source and degree of reliance on N-fixation can impact plant nitrogen dynamics, which has the potential to impact above-ground herbivore performance. We examined the impact of nitrogen availability and rhizobial association on soybean aphid biology and reproduction in a series of greenhouse and field experiments. Aphid establishment on plants was not significantly affected in any experiment. However, aphid reproduction was significantly affected by rate of nitrogen fertilization, rhizobial inoculation, and type of rhizobial seed inoculant. In general, aphid densities were not correlated with plant parameters associated with plant nitrogen or N-fixation. Producers commonly use fertilizers and rhizobial seed inoculants, thus it is important to continue exploring the mechanisms underlying how plant nitrogen dynamics impact soybean insect pests.
20
Behrens, Nicholas Scott. "Pan trapping soybean aphids, Aphis glycines Matsumura (Hemiptera: Aphididae), using sex pheromones and plant volatiles". [Ames, Iowa : Iowa State University], 2010. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1476273.
21
Warren, Peter L., e Jeff Schalau. "Aphids". College of Agriculture, University of Arizona (Tucson, AZ), 2014. http://hdl.handle.net/10150/324020.
22
Sacranie, Sattar Farouk. "An investigation on the effect of Russian wheat aphid (Diuraphis noxia Kurdjumov) population growth and feeding damage on selected barley (Hordeum vulgare L.) cultivars under ambient and elevated CO2". Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/50311.
Abstract (sommario):
The Russian wheat aphid (RWA) (Diuraphis noxia Kurdjumov) is a major pest of cultivated small grains. It is particularly devastating because of is high reproductive rate which results in the growth of large populations which become damaging to its host plants. Development of resistant barley (Hordeum vulgare L.) cultivars is complicated as resistance is polygenic. As a result, the industry remains at risk now that the RWA has spread throughout South Africa. It has, as recently as, 2013, been identified in the SW Cape, which was previously geographically isolated. This is South Africa‟s principle barley growing region. Now a potentially huge problem exists. Therefore, it is imperative that an alternative to pesticide use is found. Testing potential innate resistance in barley cultivars is thus, critical. In this thesis, I present data on four barely cultivars where I have examined their resistance/ lack of resistance to three known RWA biotypes, RWASA1, RWASA2 and RWASA3. The barley varieties used were two economically important South African malt barley cultivars (S5 and SSG 564) along with two potentially RWA resistant Afghan accessions (CIho 4125 and CIho 4159). The RWA biotype population growth rates on each of the plants were determined over a 14 day period. The aim was to establish baseline data of the effects of RWA population growth on the host plants under ambient CO2 (380 – 400 ppm) conditions. The extent of RWA feeding damage was investigated at the cell level by examining saliva deposition and cell disruption using Transmission Electron Microscopy; at the tissue/vascular level using fluorescence microscopy, to determine the extent of callose formation; at a whole leaf level by recording percent chlorosis and leaf roll; and finally, at a whole plant level by measuring biomass loss.The experiments were repeated under elevated CO2 (450 ppm) to model any changes in RWA/plant interaction with respect to future climate change. The effects of an elevated CO2 environment and RWA feeding on host plant foliar N and C:N ratio were compared to ambient CO2 conditions, to provide a clearer picture of the potential nutrient drain that a feeding RWA colony exacts on its host. Of the varieties tested, the CIho accessions performed better than the two SA barley cultivars as the CIho accessions appeared to express a mild antibiosis resistance response as RWA populations, particularly those of RWASA1, were smaller than those observed on either S5 or SSG 564. In addition, less damage was evident in the two CIho accessions due to RWA feeding. II RWASA2 was the most virulent of the three RWA biotypes tested, followed by RWASA3 while RWASA1 was the least virulent. Under elevated CO2 conditions, RWA feeding damage was exacerbated but the trend of biotype virulence remained the same. Higher aphid population sizes were recorded under elevated CO2, meant that even the more resistant CIho accessions were overcome by the increased demand made by the larger aphid colonies on the host plants. The % foliar N data showed that under elevated CO2 aphid-free control plants had increased N levels in their leaves. Increased “food” supply (as shown by the increased N levels) therefore allowed significantly larger aphid populations to develop on the plants exposed to elevated CO2, due to improved nutrient status of the phloem sap taken up by RWA. The knock-on effect of a higher aphid population was increased cell disruption as a result of extensive probing, extensive formations of wound callose, with the result that phloem damage impeded nutrient flow through the vascular tissues which contributed to chlorosis and (eventually plant) death. The major conclusion from this study is that even a mild CO2 elevation resulted in an increase aphid population which may pose a severe and very real threat to a barley crop. Therefore, without effort to identify and deploy resistant barley cultivars, it could well be possible that future barley cultivation in South Africa may no longer be viable.
23
Hough, Ashley Rose. "The indirect and direct effects of temperature and host plant resistance on population growth of soybean aphid (Aphis glycines) biotype 1". Thesis, Kansas State University, 2016. http://hdl.handle.net/2097/32584.
Abstract (sommario):
Master of ScienceDepartment of Entomology
James R. Nechols
Temperature has an important indirect impact on pest populations. Direct effects occur, but also may result from temperature-induced changes in plant quality, including the expression of host plant resistance traits. Therefore, I examined both indirect and direct effects of temperature on biotype 1 soybean aphids (SBA), Aphis glycines, on a Rag1-resistant soybean variety and compared the effects with a susceptible variety to gain a better understanding of how temperature impacts SBA. Four aphid responses were evaluated: preimaginal development, survival to adulthood, number of progeny produced, and adult longevity. In the first experiment, I grew soybean seedlings to the V-0 stage at 25°C and then conditioned them for 0, 3 or 5 days at 20° or 30°C before infesting with a single first instar SBA at each of the two experimental temperatures. Based on previous literature for SBA, I hypothesized that conditioning plants at the lower temperature would cause resistance to break down and that longer exposure would exacerbate the effect. Results showed that conditioning soybeans to 20°C significantly reduced SBA survival, and the effect on survival increased with longer conditioning. Conditioning plants to 30°C had no significant effect on SBA survival. However, estimated population growth decreased as conditioning time increased at 30°C and this effect was also observed at 20°C. Thus, plant resistance may have increased at both temperatures. The second experiment compared SBA responses, including population growth, at four temperatures (15, 20, 25, and 30⁰C) on a Rag1-resistant and susceptible soybean variety. I predicted that SBA fitness would be lower at all temperatures on resistant soybeans, but the magnitude of differences between cultivars would not be uniform across temperatures. Results indicated that both temperature (highest and lowest) and plant resistance detrimentally affected SBA fitness. There was also a significant interaction between the two variables with respect to SBA survival. Survival was lower and development rates were slower on the resistant cultivar. SBA required more degree-days to develop on resistant soybeans compared to the susceptible cultivar. This information will aid soybean producers in implementing a cost-efficient IPM strategy involving Rag1 resistant soybeans to combat SBA under a range of temperatures.
24
Wulff, Jason A. "THE ROLE OF THE BACTERIAL ENDOSYMBIONT, ARSENOPHONUS, IN THE SOYBEAN APHID, APHIS GLYCINES". UKnowledge, 2014. http://uknowledge.uky.edu/entomology_etds/7.
Abstract (sommario):
Bacterial endosymbionts can have profound impacts on their host’s ecology. Notably, endosymbionts can protect their hosts against natural enemies and influence host plant interactions. The endosymbiont Candidatus Arsenophonus infects a wide taxonomic range of arthropod hosts, and is suspected of an uncharacterized mutualistic role in hemipterous insects. In the soybean aphid, Aphis glycines, an introduced pest of soybeans in the United States, Arsenophonus is the sole facultative endosymbiont. The focus of this dissertation is to characterize the role of Arsenophonus in the aphid, with an overall emphasis on its impact on aphid management strategies.
I first used diagnostic PCR to determine Arsenophonus infection frequency and strain diversity for native and introduced soybean aphids. I found that Arsenophonus infection is a uniform strain that is highly prevalent in soybean aphid. I then determined if Arsenophonus was a defense symbiont by curing two genotypes of soybean aphid of their natural Arsenophonus infection, resulting in infected and uninfected isolines within the same genetic background. I subjected these isolines to assays with three parasitoid species and a common aphid fungal pathogen, Pandora neoaphidis. I did not find differences in parasitism or fungal infections within the treatments. These results indicate that, although Arsenophonus is widespread, the symbiont should not interfere with biological control efforts.
I next examined the influence of Arsenophonus on the ability of soybean aphid “biotypes” to colonize resistant Rag plants. I cured three additional soybean aphid biotypes. All isolines were subjected to growth rate assays on resistant Rag versus susceptible soybean. My results indicate that Arsenophonus infected soybean aphids have an increased population growth compared to uninfected aphids regardless of soybean plant type
Finally, I induced soybean plants with jasmonic acid (JA) or salicylic acid (SA) to determine the effective plant defense against soybean aphid feeding. I also used Arsenophonus infected and uninfected aphids to determine any interaction between Arsenophonus and plant defense. I found SA treatment decreased soybean aphid population growth for one experiment, but had no effect when replicated. JA treatment had no effect, and there were no interactions between Arsenophonus infection and plant treatments.
25
Klingler, John Paul. "Phenotypic and molecular-genetic analysis of resistance to Aphis gossypii (cotton-melon aphid) in Cucumis melo (melon)". Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/283992.
Abstract (sommario):
Aphis gossypii Glover (cotton-melon aphid) is a major pest of agriculture worldwide. Cucumis melo L. (melon) possesses monogenic resistance to this aphid, and is a good model for the study of aphid resistance mechanisms in plants. This dissertation presents analyses of the effects of the resistance gene on A. gossypii, and of the gene's effects on biochemical and molecular-genetic properties of melon plants. Nearly isogenic lines (NILs) of melon, either resistant or susceptible to A. gossypii, were compared for their influence on aphid life history traits and feeding behavior. The resistance trait delayed development, increased mortality, and markedly decreased reproduction of aphids confined to leaves of resistant plants. Aphids on resistant plants salivated into phloem sieve elements significantly longer, and were less likely to begin sap ingestion after salivation, suggesting that the resistance factor acts within phloem sieve elements. Biochemical properties of callose synthase were compared between NILs to test the hypothesis that callose deposition plays a role in the resistance mechanism. No differences were detected between resistant and susceptible melon genotypes with respect to callose synthase subunit abundance or in vitro enzyme activity. Sixty-four F₃ families from a melon mapping population were tested for aphid resistance to place the resistance locus on a genetic map of the melon genome. Four molecular markers were found to be linked to the aphid resistance phenotype. The name Agr ( Aphis gossypii resistance) is proposed for this locus. The closest flanking markers were positioned at 4.3 and 7.0 cM from Agr. Evidence suggests Agr might be a member of the nucleotide binding site-leucine-rich repeat (NBS-LRR) family of plant resistance genes, which are known to cluster in plant genomes. Melon genomic DNA sequences homologous to this gene family were isolated to test the hypothesis that Agr is an NBS-LRR homolog. Two of these sequences were tested for genetic linkage to Agr in a population of F₂ plants segregating for the resistance trait. DNA gel blot analysis determined that one sequence, NBS-2, is approximately 2.7 cM distant from Agr, which suggests Agr resides in a cluster of NBS-LRR homologs and could be a member of this gene family.
26
Rutz, Charlotte. "The energy budget of green apple aphids (Aphis pomi de Geer) (Homoptera: Aphididae), as influenced by nitrogen fertilization /". [S.l.] : [s.n.], 1993. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10176.
27
Orantes, Lucia C. "Population Genetics of Soybean Aphid: Elaborating Species Specific SNPs to test Bottleneck and Migration Hypotheses across North-central US and Canada". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1314029403.
28
Whalen, Rebecca Ann. "Density and Movement of Soybean Aphid, Aphis Glycines (Hemiptra: Aphididae) in Response to Temperature and Resistant Soybean Plants". Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26546.
Abstract (sommario):
Movement is one way herbivores respond to their host plant, yet the movement of relatively immobile insects has received little attention. We studied how the movement and density of apterous soybean aphids responds to a resistant soybean variety and different temperatures. In Chapter One, we examined aphid movement both within and between soybean plants that varied in their resistance to aphids. Aphids on resistant plants had a wider dispersal, apparently due to greater aphid movement. Consequently, aphids on resistant plants could move to neighboring susceptible plants, thereby increasing their density. In Chapter Two, we measured aphid density and dispersal on resistant and susceptible plants when insects and plants were exposed to two different temperatures. Here, movement behavior was affected by both plant resistance and temperature. Moreover, temperature and plant resistance interacted to influence aphid density. Our results indicate the important role that movement can play in an herbivore's response to plant resistance.
29
Letsoalo, Isaac Motsoeng. "Evaluation of introduced cowpea breeding lines for Aphid (Aphis Craccivora) and bruchid (Callosobruchus Rhodensiansus) resistance in South Africa". Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1775.
30
Mekdaschi, Studer Rima. "Interactions between green apple aphids (Aphis pomi De Geer) and apple plants (Malus domestica Borkh.) subjected to water stress /". [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10704.
31
Irving, Philabeg. "Characterisation of aphid proteins as targets for aphid control". Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368227.
32
MELO, Ricardo Lopes de. "Alternativas de controle de afídeos no cultivo da couve (Brassica oleracea) com ênfase a A Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae)". Universidade Federal Rural de Pernambuco, 2012. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6060.
Abstract (sommario):
Submitted by (edna.saturno@ufrpe.br) on 2016-12-02T12:00:19Z
No. of bitstreams: 1
Ricardo Lopes de Melo.pdf: 1316234 bytes, checksum: 08d9d42be60b63426f274a63eaa26109 (MD5)Made available in DSpace on 2016-12-02T12:00:19Z (GMT). No. of bitstreams: 1 Ricardo Lopes de Melo.pdf: 1316234 bytes, checksum: 08d9d42be60b63426f274a63eaa26109 (MD5) Previous issue date: 2012-02-03
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae) is a pest with Kale, in the absence of pesticides registered in Brazil for its control. The goal of this research was to evaluate the biological control with entomopatogênicos fungi and its association with Neem oil in aphids of Kale, with emphasis to L. erysimi. The participation of L. erysimi in complex of aphids-pest of kale in Pernambuco was evaluated. Among six municipalities monitored, L. erysimi was more frequent in João Alfredo (68,7%), Recife (63,9%) and Vitória de Santo Antão (74,6%). Cycloneda sanguinea (L.) (Coleoptera: Coccinelidae), Lysiphlebus testaiceipes (Cresson) (Hymenoptera: Aphidiidae), Lecanicillium muscarium (Petch) Zare & Gams, and Syrphidae were noted. Strains Beauveria bassiana URPE 27 and L. muscarium URPE 28 of were elected as more virulent, causing in nymphs mortality rate of 83% and 77%, survival 2,1 and 3,3 days and Lethal Concentration (LC50) of 2,4x107con./ml and 7,3x106con./ml, respectively. The neem oil when sprayed shower LC50 of 0.2mL/l and 3.7mL/l applied in immersion. The combination of neem with B. bassiana URPE 27 and L muscarium URPE 28 was compatible. In the field, the strain URPE 27 caused relative efficiency of 89.6%, 88.3% and 90.4%, while URPE 28 promoted 45.5%, 62% and 64.4% against L. erysimi, Myzus persicae (Sulzer) and Brevicoryne brassicae (L.) (Hemiptera: Aphididae), respectively. The association with the neem oil was more favorable to the strain URPE 27. In field monitoring in Viçosa-MG, to evaluate the effectiveness of Zoophthora aphids (Hoffman in Fresenius) Batko (1964b) on L. erysimi and M. persicae, which showed average proportion of infected of 0.24 and 0.30, respectively. The third instar stage L. erysimi more likely.
Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae) é uma praga relevante para couve, não existindo agrotóxicos registrados no Brasil para o seu controle. O objetivo desta pesquisa foi avaliar o controle biológico com fungos entomopatogênicos e a sua associação com óleo de nim em afídeos da couve, com ênfase para L. erysimi. A participação deste, no complexo de pragas da couve em Pernambuco foi avaliada. Dentre os seis municípios monitorados L. erysimi mostrou-se mais freqüente em João Alfredo (68,7%), Recife (63,9%) e Vitória de Santo Antão (74,6%). Cycloneda sanguinea (L.) (Coleoptera: Coccinelidae), Lysiphlebus testaiceipes (Cresson) (Hymenoptera: Aphidiidae), Syrphidae e Lecanicillium muscarium (Petch) Zare & Gams foram constatados. As linhagens de Beauveria bassiana URPE 27 e de Lecanicillium muscarium URPE 28 foram eleitas como mais virulentas, causando em ninfas taxa de mortalidade de 83% e 77%, sobrevivência 2,1 e 3,3 dias e Concentração Letal (CL50) de 2,4x107con/ml e 7,3x106con/ml, respectivamente. O óleo de nim, quando pulverizado apresentou CL50 de 0,2mL/l e de 3,7mL/l, aplicado em imersão. O óleo em concentração de 1,25mL/l causou mortalidade de 80% das ninfas em 24horas. Efeito fitotóxico foi promovido em concentrações acima de 2,5mL/L. A associação do nim com B. bassiana URPE 27 e L. muscarium URPE 28 mostrou-se compatível. Em campo, a linhagem URPE 27 causou eficiência relativa de 89,6%, 88,3% e 90,4%, enquanto que URPE 28 promoveu 45,5%, 62% e 64,4% contra L. erysimi, Myzus persicae (Sulzer) e Brevicoryne brassicae (L.) (Hemiptera: Aphididae), respectivamente. A associação com o óleo de nim mostrou-se mais favorável com a linhagem URPE 27. Em monitoramento de campo em Viçosa- MG, avaliou-se a eficácia de Zoophthora aphids (Hoffmann in Fresenius) Batko (1964b) sobre L. erysimi e M. persicae, que apresentou proporção média de infectados de 0,24 e 0,30, respectivamente. O terceiro ínstar foi a fase de L. erysimi mais susceptível.
33
Matsiliza, Babalwa. "Observations of selective feeding of the aphid, Sitobion yakini (eastop) on leaf blades of barley (Hordeum vulgare L)". Thesis, Rhodes University, 2000. http://eprints.ru.ac.za/37/.
34
Kaakeh, Walid. "The effect of spirea aphid (Homoptera: aphididae) feeding and nitrogen fertilization on the growth of young apple trees, with comparisons to apple aphid". Diss., This resource online, 1989. http://scholar.lib.vt.edu/theses/available/etd-11072008-063502/.
35
TEIXEIRA, Ana Caroline de Azevedo. "Avaliação de fungos entomopatogênicos para o controle de Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) em pepino Cucumis sativus L. e desenvolvimento de um inseticida à base de Beauveria bassiana (Bals.) Vuill". Universidade Federal Rural de Pernambuco, 2015. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5519.
Abstract (sommario):
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-08-30T13:40:23Z
No. of bitstreams: 1
Ana Caroline de Azevedo Teixeira.pdf: 500119 bytes, checksum: c6f5c469790bac6fbe0bfe816ac29466 (MD5)Made available in DSpace on 2016-08-30T13:40:23Z (GMT). No. of bitstreams: 1 Ana Caroline de Azevedo Teixeira.pdf: 500119 bytes, checksum: c6f5c469790bac6fbe0bfe816ac29466 (MD5) Previous issue date: 2015-02-27
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Cucumber crop has its production affected by the attack of the aphid Aphis gossypii Glover (Hemiptera: Aphididae), which colonizes the plant throughout all developmental stages. The use of chemical insecticides to control it has generated serious problems such as the emergence of resistant populations to the active ingredients used. This work aimed to evaluate fungus preparations based on entomopathogenic to control this insect pest in cucumber plants, and develop an insecticide the base of Beauveria bassiana (Bals.) Vuill. Under laboratory conditions, the three most promising isolates were tested, CG 864, PL 63 and IBCB 66,with five concentrations of conidia (1x105, 1x106, 1x107, 1x108 and 1x109 conidia / ml) and control (sterile water + Tween 80) . In the third stage of the experiments studies were conducted involving two preparations of biological insecticide: a) an aqueous suspension [pure conidia of B. bassiana 864 CG + 0.01% Tween 80; used as a standard] b) formulation of oil dispersion [conidia pure vegetable oil emulsifiable +] CG 864 isolated, and diluted with water for spraying the concentrations of 0.5; 1; 2 and 4% oil. The fungus preparations were standardized to have 1.0 x 107 spores / mL in applied spray. Isolates of the fungus B. bassiana were more virulent aphid A. gossypii that isolates Metarhizium anisopliae (Metschn.) Sorok. and Lecanicillium longisporum (Zimmerman) Zare & Gams. The isolates CG 864, IBCB 66 and PL 63 of the B. bassiana were the most virulent. B. bassiana preparations reduced the aphid population A. gossypii, with control efficiencies of 52.3% to 83.8%, however, there was no difference in the pest population density between the oil dispersion and the aqueous suspension conidia.
A cultura do pepino tem sua produção afetada pelo ataque do pulgão Aphis gossypii Glover (Hemiptera: Aphididae), que coloniza a planta durante todo seu estágio fenológico. O uso de inseticidas químicos para seu controle tem gerado sérios problemas, como o surgimento de populações resistentes aos princípios ativos utilizados. Este trabalho teve por objetivo avaliar preparações à base de fungo entomopatogênico para controle desse inseto-praga em plantas de pepino e desenvolver um inseticida a base de Beauveria bassiana (Bals.) Vuill. Em condições de laboratório, os três isolados mais promissores CG 864, PL 63 e IBCB 66, foram testados, com cinco concentrações de conídios (1x105; 1x106; 1x107; 1x108 e 1x109 conídios/mL) e a testemunha (água esterilizada +Tween 80). Foram realizados estudos envolvendo duas preparações do inseticida biológico: a) suspensão aquosa (conídios puros de B. bassiana CG 864 + Tween 80 a 0,01%), utilizada como padrão e b) formulação em dispersão oleosa [conídios puros + óleo vegetal emulsionável], do isolado CG 864, sendo diluída em água para pulverização nas concentrações de 0,5, 1; 2; 4; 8 e 16% de óleo. As preparações do fungo foram padronizadas para 1,0 x 107 conídios/mL na calda aplicada. Isolados do fungo B. bassiana foram mais virulentos ao pulgão A. gossypii que os isolados de Metarhizium anisopliae (Metschn.) Sorok. e Lecanicillium longisporum (Zimmerman) Zare & Gams. Os isolados CG 864, IBCB 66 e PL 63 de B. bassiana foram os mais promissores. Preparações de B. bassiana reduziram a população do pulgão A. gossypii, com níveis de eficiência de controle de 52,3% a 83,8%, porém, não houve diferença na densidade populacional da praga entre a dispersão oleosa e a suspensão aquosa de conídios.
36
Knowles, Tim C. "Alfalfa Aphid Complex". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/146689.
Abstract (sommario):
4 pp.The alfalfa aphid discussed in this publication includes blue alfalfa aphid, pea aphid, and the spotted alfalfa aphid. This publication discusses the biology of these alfalfa aphids, the damages they cause, the resistant varieties and biological control, and their monitoring and treatments.
37
Hodgson, David James. "Evolutionary ecology of aphids". Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299855.
38
Kundu, Ranajit. "Host alternation in aphids". Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241092.
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Kuklinski, Frank. "The cotton pests in Madagascar with special emphasis on the cotton aphid Aphis gossypii (Hom.: Aphididae) and its natural enemies /". [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959594116.
40
Chen, Jian-Qun. "Caractérisation biologique et chimique de la résistance monogénique du melon (gène Vat, pour virus aphid transmission) au puceron Aphis gossypii". Lyon, INSA, 1996. http://www.theses.fr/1996ISAL0147.
Abstract (sommario):
Le gène vat (pour virus aphid transmission) monogénique dominant chez le melon gouverne à la fois la résistance par antixénose contre le puceron du melon Aphis gossypii et une résistance à la transmission des virus non persistants. Nous avons étudié les caractéristiques comportementales et la localisation tissulaire de la résistance par EPG et par tests biologiques et nous avons comparé les compositions en composés aminés, en peptide, en protéines et en dérivés du pyrazole de la sève phloémienne récoltée chez deux lignées isogéniques de melon (Cucumis melo L. ) portant ou non le gène vat. Toutes les données comportementales ou chimiques montrent que cette résistance est constitutive. L'analyse EPG des pucerons piquant un génotype résistant montre clairement que les paramètres chimiques sont perçus très tôt après le contact avec la plante, durant la pénétration aussi bien que lors du contact avec le phloème, révélant ainsi que les effets du gène vat sont exprimés dans le préphloème et dans le phloème. Ceci a été confirmé par des tests biologiques qui démontrent la présence de facteurs chimiques extractibles discriminant les génotypesThe vat (for virus aphid transmission, monogenic, dominant) resistance gene in melon governs both antixenosis towards the melon aphid Aphis gossypii Glover and a resistance to non-persistent virus transmission. We investigated the behavioral features and tissue localization of the antixenosis resistance by EPG and bioassay, and compared the chemical composition in amino compounds, peptides, proteins and pyrazole derivatives of the phloem sap collected from two isogenic lines of melon (Cucumis melo L. ), carrying or not the vat gene. All behavioral and chemical data indicate that this resistance is constitutive. EPG analysis of aphids probing on the resistant genotype clearly showed that chemical cues were perceived very early after plant contact, during the penetration phase as well as after phloem localisation, revealing that the effects of the vat gene are unambiguously expressed in the pre-phloem and phloem. This was confirmed by bioassay that demonstrated the presence of extractable chemical factors discriminating the genotypes
41
Storer, John Robert Gerard. "An investigation into the natural plant resistance of autumn flowering chrysanthemums to the aphids Myzus persicae (Sulzer) and Aphis gossypii glover". Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317636.
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Glinwood, Robert Thomas. "Responses of aphid parasitoids to aphid sex pheromones : laboratory and field studies". Thesis, University of Nottingham, 1998. http://eprints.nottingham.ac.uk/13861/.
Abstract (sommario):
The behavioural responses of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) to aphid sex pheromones were investigated in the laboratory and field. In a wind tunnel bioassay, Aphidius eadyi, Aphidius rhopalosiphi, Diaeretiella rapae, Ephedrus plagiator, Praon myzophagum and Praon volucre responded to the aphid sex pheromone components nepetalactone and nepetalactol. P. myzophagum reared on two different host aphid species showed different responses to combinations of nepetalactone and nepetalactol in the wind tunnel, indicating that long term laboratory rearing may influence parasitoid responses to aphid sex pheromones. The ability of two aphid parasitoids to learn aphid sex pheromones through prior exposure in the presence of host aphids was investigated. The generalist E. plagiator showed evidence of associative learning, whereas the specialist Aphidius ervi did not. When A. ervi was exposed to the pheromone without contact with host aphids, the parasitoid response was reduced by habituation. Exposure to aphid sex pheromone during laboratory host attack trials had no effect on the host attack behaviour of A. ervi. In laboratory cage experiments, aphid sex pheromone lures increased the retention of A. rhopalosiphi, but not by Praon volucre, on aphid-infested plants. In a wind tunnel bioassay, aphid sex pheromone enhanced the attraction of A. ervi to a plant-host complex. In the field, aphid sex pheromone lures increased parasitisation rates by A. rhopalosiphi and P. volucre on aphid-infested potted plants. A series of potted plant experiments indicated that the pheromone may increase parasitisation of aphids by A. rhopalosiphi, but not P. volucre, at a distance of 1m away from the lure. The effect of baiting plots of winter wheat with aphid sex pheromone was investigated in two field experiments. In 1996, the number of parasitoid mummies was higher in baited plots than in unbaited plots, and the synchrony between aphid and parasitoid populations was closer in baited plots. In 1997, aphid sex pheromone had no effect on parasitisation levels. The results are discussed in the context of developing a novel aphid control strategy based on the use of aphid sex pheromones to manipulate parasitoid populations.
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Chiozza, Mariana Victoria. "Exploring soybean aphid (Aphis glycines Matsumura) resistance germplasm across the Midwest and its relationship with free amino acids accumulation in leaves". [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1468149.
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McVean, Ross Iolo Kester. "Forecasting pea aphid outbreaks". Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389386.
45
Umeda, K., G. Gal e J. Murrieta. "Aphid Control in Broccoli". College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/221657.
Abstract (sommario):
In a small plot field test, imidacloprid (Provado®), oxydemeton- methyl (Metasystox-R®), RH -7988 (Aphisttar®, Rohm and Haas), pirimicarb (Pirimor®), methamidaphos (Monitor®), and endosulfan were effective in significantly reducing the number of aphids in broccoli within 4 days of treatment (DAT). At 14 DAT, Provado, Metasystox-R, and Monitor continued to exhibit a significant reduction of aphids relative to the untreated check Pymetrozine (CGA- 215944, Novartis) at 0.022 lb AI/A did not effectively reduce aphids in this test.
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Umeda, K., G. Gal e J. Murrieta. "Aphid Control in Spinach". College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/221676.
Abstract (sommario):
Several newly introduced insecticides that have potential for use in vegetable crops for aphid control were evaluated and demonstrated very good efficacy against green peach aphid (Myzus persicae). Field testing in spinach showed that CGA-293343 (Novartis) at the two rates tested significantly reduced the number of aphids relative to the untreated check. CGA-215944 (pymetrozine -Novartis) effectively reduced the number of aphids after two applications. Aphistar (RH- 7988 - Rohm and Haas) demonstrated the greatest reduction in the number of aphids per plant after each application. Provado (imidacloprid) and Thiodan (endosulfan) were applied as commercially available standard treatments and effectively reduced the number of aphids relative to the untreated check. Pirimor (pirimicarb) numerically reduced the number of aphids but was not significantly different relative to the untreated check.
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Jenkins, Rhodri Lloyd. "Colour and symbionts of aphids". Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294089.
Abstract (sommario):
The colour of the green and brown forms of Silobion avenae result from qualitative and quantitative differences in their carotene pigments. The green form contained mainly a-carotene (bicyclic), and the brown form mainly y-carotene (monocyclic), lycopene, torulene and 3', 4'-didehydrolycopene (acyclic). The total carotene content of the brown form was approximately three times higher than the green form. The striking pink colour of male Metopolophium dirhodum was the result of qualitative differences in carotenes present in the green vir'ginoparae of this species. To investigate the possibility that *brown clones had a selective advantage over green clones at long " daylengths, six clones of S. avenae (three green and three dark), were reared on artificial diet, at photoperiods of either 8,16 or 24 h. The fecundity of five of the clones was highest at 16 h and lowest at 8h. One of the brown clones had its highest fecundity at 24 h and lowest at 8h. These results do not support the hypothesis that brown clones have a selective advantage at long daylengths. When a green and a brown clone were exposed to UV light (58 tmol m-2), the brown clone suffered the least mortality and had a significantly lower reduction in fecundity. This result suggests that at high light intensities brown clones have a selective advantage over green clones. Another possible source of selective advantage investigated was the number of bacteriacytes individuals of the above clones possessed. This was estimated by histological examination and no significant difference was foundThe carotenes of S. avenae are not derived from an exogenous source, as three clones were reared on a diet lacking carotenoids for up to three generations, with no loss of pigmentation. Adding chlorotetracycline to the diet did not inhibit the production of carotenes. This result suggests that the symbionts are not synthesising the carotenes. The colour of the offspring of virginoparae, reared on artificial diet at a number of different daylengths, was not affected. When sexual morphs were induced, the oviparae of the brown forms were green. Individuals of an insecticide resistant strain of Myzus persicae, whose symbionts were disrupted by feeding them on a diet containing antibiotic did not show a reduction in the base level of esterase E4 activity, the enzyme conferring resistance in this species. This demonstrates that the bacteriasome is probably not the major site of synthesis of this enzyme
48
Couldridge, Clare Elizabeth. "Aphid-plant interactions : investigating plant molecular response with implications for aphid pest control". Thesis, University of Birmingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487497.
49
Reed, Thomas David. "Quantification of tobacco aphid, Myzus nicotianae Blackman, injury to flue-cured tobacco, Nicotiana tabacum (L.) /". This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-07282008-135337/.
50
Winter, Rebekah Sian. "Reproductive isolation in the Aphis fabae complex". Thesis, University of East Anglia, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296810.