Artículos de revistas: "Gc-Eag"

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Bestmann, H. J., F. Kern, G. G. Melikyan, D. Schäfer, O. Vostrowsky, E. V. Babayan y Sh O. Badanyan. "Pheromones, 88 [1]. Sex Pheromone Components of Female Euzophera punicaella M. (Lepidoptera, Pyralidae)". Zeitschrift für Naturforschung C 48, n.º 1-2 (1 de febrero de 1993): 110–12. http://dx.doi.org/10.1515/znc-1993-1-221.

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By means of GC, GC-MS and GC-combined EAG recordings (9Z,12E)-9,12-tetradecadien-1-ol (1) and (9Z,12E)-9,12-tetradecadienyl acetate (2) in a ratio of 4:1 were identified as the pheromone components of the female pyralid moth Euzophera punicaella M. originating from Armenia. Determination of EAG activity with male moth antennae and synthetic test chemicals revealed best responses with a mixture of both compounds.

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Ramos, Clécio S., Marisi G. Soares, Adalberto M. da Silva, Luciane G. Batista-Pereira, Arlene G. Corrêa y Massuo J. Kato. "Electrophysiological Responses of the Naupactus bipes Beetle to Essential Oils from Piperaceae Species". Natural Product Communications 7, n.º 8 (agosto de 2012): 1934578X1200700. http://dx.doi.org/10.1177/1934578x1200700835.

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Electrophysiological responses based on electroantennographic detection (GC-EAD) and electroantennography (EAG) analysis of Naupactus bipes beetles (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) were used to test volatile oils of Piper gaudichaudianum, P. regnellii and P. hispidum. In the EAG experiments, female and male beetles showed significant EAG response to the three volatile oils of Piper species, with the females’ responses slightly higher than the males’. The experiments with GC-EAD revealed that some terpenoids (namely, α-pinene, β-pinene, myrcene, α-copaene and germacrene) present in the leaf essential oils of the Piper species are perceptible to female and male beetles.

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Li, Chongyang, Jianmin Cao, Xiufang Wang, Pengjun Xu, Xinwei Wang y Guangwei Ren. "Efficacy of an improved method to screen semiochemicals of insect". PeerJ 9 (20 de mayo de 2021): e11510. http://dx.doi.org/10.7717/peerj.11510.

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Background A combination of gas chromatography-electroantennographic detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS) is typically used to screen active compounds that play a role in the regulation of insect behavior. This method uses two kinds of gas chromatography (GC) equipment and needs to compare compounds between the two chromatograms, and it is tedious and costly. To improve detection efficiency, as well as reduce costs and the rate of missed detection, we designed a system connecting gas chromatography (GC), electroantennography (EAG), and mass spectrometry (MS), with MS used instead of the flame ionization detector (FID) as the GC-EAD detector. To verify the feasibility of the improved method, we compare two methods—GC-EAG-MS and GC-EAD—through a series of experiments. Some researchers made similar improvements, but these were not compared with GC-EAD, and their method needed to be improved in the synchronization and split ratio. Our method has been optimized and improved in these aspects. Methods Helicoverpa armigera was the test organism; the improved method and conventional method were used to detect known and unknown compounds, as well as screen out active compounds that could generate responses in H. armigera antennae. Results Screening known single compounds using the two methods, the active compound benzaldehyde was detected in all seven concentrations of solution. By using the two methods, the five same active compounds of Helicoverpa armigera were detected in high concentration solution of the mixed compounds (100 mg L−1, 50 mg L−1); the four same active compounds were detected at 20 mg L−1 concentration; two identical same compounds were detected in low concentration solution (concentrations of 10 mg L−1 and below). By using the two methods, six identical active compounds of Helicoverpa armigera were detected in unknown compounds. Conclusion The improved method was consistent with the conventional method in terms of accuracy and sensitivity. However, compared with the traditional methods, Gas chromatography-electroantennographic-mass spectrometry (GC-EAG-MS) saved the cost of GC and FID equipment, thereby greatly lowering the experimental cost. In the experiment, GC-EAG-MS combined the two experimental operations of screening active substances by GC-EAD and identifying active substances by GC-MS into one, which not only reduced the experimental steps, but also avoided the false positive caused by the comparison of the two chromatograms, and it greatly reduced the difficulty level of the overall experimental analysis. GC-EAG-MS is more convenient, efficient, economical, and practical, and could confidently replace traditional methods. With further optimization, it could be widely applied in the study of plant and insect chemical ecology.

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Magsi, Fida Hussain, Zongxiu Luo, Yingjie Zhao, Zhaoqun Li, Xiaoming Cai, Lei Bian y Zongmao Chen. "Electrophysiological and Behavioral Responses of Dasychira baibarana (Lepidoptera: Lymantriidae) to Tea Plant Volatiles". Environmental Entomology 50, n.º 3 (3 de marzo de 2021): 589–98. http://dx.doi.org/10.1093/ee/nvab016.

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Abstract Tea black tussock moth, Dasychira baibarana (Matsumura) (Lepidoptera: Lymantriidae), is a devastating pest species of the tea plant in China. Here, we evaluated the responses of D. baibarana to tea plant volatiles using gas chromatography coupled electroantennographic detection (GC–EAD), eleclectroantennography (EAG), and a Y-tube olfactometer. In total, 11 of 18 analyzed compounds elicited GC–EAD responses from test insects. GC–EAD bio-active compounds were further investigated using EAG and behavioral responses. In the EAG analysis, male moths had significantly greater responses to four compounds [(Z)-3-hexenyl butyrate, (Z)-3-hexen-1-ol, ocimene and benzyl alcohol] than female moths. For females, maximum EAG amplitudes, were recorded in response to linalool, (Z)-3-hexenyl hexanoate and (Z)-jasmone. In EAG and behavioral bio-assays, the responses of both sexes were dose independent. In behavioral bio-assays male moths responding significantly to (Z)-3-hexen-1-ol, ocimene, (Z)-3-hexenyl butyrate, linalool, benzyl alcohol, and (Z)-jasmone at various concentrations. For females, significant behavioral responses were observed to (Z)-3-hexenyl hexanoate, followed by (Z)-jasmone, linalool, ocimene, and benzyl alcohol. However, neither sex was sensitive to 4 of the 11 tested compounds, phenyethyl alcohol, phenylacetonitrile, (E)-nerolidol, and indole. The present results showed that tea plant volatiles influenced the behavior of D. baibarana moths, which will greatly contribute in developing eco-friendly control strategies for D. baibarana, through the application of a blend of compounds that showed significant EAG and behavioral responses or a blend combined with female-produced sex pheromones.

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Hayashi, Nanao, Akihiko Nishi, Tadayuki Murakami, Kazuyuki Maeshima, Hisashi Komae y Takashi Sakao. "The Scent Substances of Pierid Butterflies (Hebomoia glaucippe Linnaeus) and the Volatile Components of Their Food Plants (Crataeva religiosa Forst.)". Zeitschrift für Naturforschung C 40, n.º 1-2 (1 de febrero de 1985): 47–50. http://dx.doi.org/10.1515/znc-1985-1-211.

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The scent secretions of two subspecies of Hebomoia glaucippe, which are pierid butterflies, and the essential oils of their food plant were investigated by means of GC and GC-MS. The scent substances of either subspecies are found to be only E-β-ocimene, and the volatile components of Crataeva religiosa were identified as 2-hexanal, 3-hexen-1-ol, p-cymene, limonene, linalool, α-ionone, and β-ionone. Electroantennogram (EAG) were recorded with the antennae of adult male and female butterflies. It was found that EAG responses of male to E-β-ocimene were greater than those of females.

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Bestmann, Hans-Jürgen, Athula Attygalle, Hans Platz, Otto Vostrowsky y Michael Glas. "(Z)-9-Dodecenyl Acetate, a Component of the Sex Pheromone of Cnephasia longana Haworth (Lepidoptera: Tortricidae)". Zeitschrift für Naturforschung C 40, n.º 9-10 (1 de agosto de 1985): 667–69. http://dx.doi.org/10.1515/znc-1985-9-1014.

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Abstract By means of electrophysiological investigations, GC- and GCMS-analysis of gland extracts and GC-analysis with EAG-detection (Z)-9-dodecenyl acetate was proven to be a component of the sex pheromone of female Cnephasia longana moths. (E)-9-dodecenyl acetate acts as a pheromone inhibitor, as shown by field trials.

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Bestmann, Hans-Jürgen, Athula B. Attygalle, Thorolf Brosche, Joachim Erler, Hans Platz, Jürgen Schwarz, Otto Vostrowsky, Wu Cai-Hong, Karl Ernst Kaissling y Chen Te-Ming. "Identification of Three Sex Pheromone Components of the Female Saturniid Moth Antheraea pernyi (Lepidoptera: Saturniidae)". Zeitschrift für Naturforschung C 42, n.º 5 (1 de mayo de 1987): 631–36. http://dx.doi.org/10.1515/znc-1987-0521.

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Abstract By means of electroantennography and single cell recordings, GC and GCMS analyses and GC analysis with EAG detection (6E,11 Z)-6,11-hexadecadienal, (6E,11 Z)-6,11-hexadecadienyl acetate and (4E,9Z)-4,9-tetradecadienyl acetate were identified as the primary components of the sex pheromone of female Antheraea pernyi (Lepidoptera: Saturniidae).

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Jham, Gulab N., Alexsandro A. da Silva, Eraldo R. Lima y Paulo Viana. "Identification (GC and GC-MS) of unsaturated acetates inElasmopalpus lignosellus and their biological activity (GC-EAD and EAG)". Journal of Separation Science 28, n.º 3 (febrero de 2005): 281–85. http://dx.doi.org/10.1002/jssc.200401814.

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Būda, Vincas, Sandra Radžiutė, Violeta Apšegaitė, Laima Blažytė-Čereškienė, Rasa Čepulytė, Gabrielė Bumbulytė y Raimondas Mozūraitis. "Electroantennographic and Behavioural Responses of European Cherry Fruit Fly, Rhagoletis cerasi, to the Volatile Organic Compounds from Sour Cherry, Prunus cerasus, Fruit". Insects 13, n.º 2 (21 de enero de 2022): 114. http://dx.doi.org/10.3390/insects13020114.

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European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is the most important pest of sweet and sour cherry fruit. This fly is difficult to control by insecticide application since most of the conventional insecticides used have been banned in Europe. Traps are used for both the pest’s mass trapping and the detection of the beginning of the flight period. Data on flies’ reactions to host-plant volatile organic compounds (VOCs) can be used to search for new attractants. VOCs were collected from the headspace of sour cherry, P. cerasus, fruit. Gas chromatography–mass spectrometry (GC–MS) resulted in the identification of 51 compounds. Terpenes and esters predominated in two aspects: in the highest diversity of the compounds, and the amount of the total VOC emissions (62.3%). Among the single VOCs, ethyl octanoate prevails, followed by (E)-4,8-dimethyl-1,3,7-nonatriene. GC–electroantennographic detection (GC–EAD) revealed 14 EAG-active compounds and those were identified. In Y-tube olfactometer tests, EAG-active compounds ((E)-β-ocimene, linalool, and (Z)-3-hexenyl 3-methylbutanoate) attracted R. cerasi females in a similar way to the odour of sour cherry fruit.

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Lahondère, Chloé. "Mosquito Electroantennogram Recordings". Cold Spring Harbor Protocols 2022, n.º 9 (28 de julio de 2022): PROT107871. http://dx.doi.org/10.1101/pdb.prot107871.

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Electroantennography (EAG) is a simple, yet powerful technique that can be used to indicate that chemical compounds are detected by mosquito antennae. When coupled with gas chromatography (GC), it allows for the identification of detectable compounds within complex mixtures, including those in plant and animal headspaces that might influence mosquito behavior. EAGs and GC-EAGs reveal compounds that can be tested in behavioral assays with the goal of developing new repellents or attractants for mosquito control.

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Zhao, Dong Xiang, Yu Jie Wang, Jing Lin Gao, Zheng Qiang Peng, Jiong Yin y Wen Jing Zhu. "Biological Activity and Component Analysis on Body Surface Extracts of Adult Tessaratoma Papillosa". Applied Mechanics and Materials 108 (octubre de 2011): 331–37. http://dx.doi.org/10.4028/www.scientific.net/amm.108.331.

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Preliminary results of petri dish bioassay showed that n-hexane and ether extracts of body surfaces of female and male Tessaratoma papillosa (Drury) were significantly attractive to the opposite sex and the same sex respectively. EAG results also demonstrated that both two kinds of solvent extracts could induce the EAG responses of adult T. papillosa. Sixteen components were identified and isolated from the extracts of adult T. papillosa body surfaces by gas chromatograph-mass spectrometer (GC-MS), of which tridecane was the common component of females and males and had the highest relative amount. In addition to three kinds of straight-chain alkanes which were undecane, dodecane and tridecane, there were other components such as (Z)-2,2-dimethyl-3-hexene, 2-hexen-1-ol acetate, (E)-2-hexen-1-ol acetate, 2,3,3-trimethyl-1-butene and 1-tridecene and others.

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Grant, G. G., B. Pendrel, K. N. Slessor, X. Z. Meng y W. E. Miller. "IDENTIFICATION OF SEX PHEROMONE COMPONENTS FOR TWO LEPIDOPTERAN DEFOLIATORS, THE OAK OLETHREUTID LEAFROLLER, PSEUDEXENTERA SPOLIANA (CLEMENS), AND THE ASPEN LEAFROLLER, PSEUDEXENTERA OREGONANA (WALSINGHAM)". Canadian Entomologist 123, n.º 6 (diciembre de 1991): 1209–18. http://dx.doi.org/10.4039/ent1231209-6.

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AbstractMoths of the genus Pseudexentera are early-season fliers that include three species of economic importance: P. spoliana (Clemens) on oak (Quercus), P. oregonana (Walsingham) on aspen (Populus), and P. mali Freeman on apple (Malus). GC and GC/MS analysis, EAG and behavioral bioassays, and field tests confirmed that Z10-16:Ac is an attractive sex pheromone component of female P. spoliana. Capillary GC analysis supported by GC/MS also indicated the presence of 16:Ac, Z10-16:OH, and 16:OH in pheromone extracts and there was tentative GC evidence for Z12-16:Ac. However, addition of these compounds to Z10-16:Ac in various blends did not enhance male attraction. The major sex pheromone component of female P. oregonana is Z8-14:Ac. There was also GC and GC/MS evidence for Z8-14:OH and tentative GC evidence for 14:Ac in the pheromone of this species. Their addition to Z8-14:Ac failed to increase moth catches in baited traps. Pseudexentera mali males were attracted by Z,Z-8,10-16:Ac, a previously reported sex pheromone of this species. Pheromone lures targeted for each species were not cross-attractive.

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Koczor, Sándor, József Vuts, John C. Caulfield, David M. Withall, André Sarria, John A. Pickett, Michael A. Birkett, Éva Bálintné Csonka y Miklós Tóth. "Sex Pheromone of the Alfalfa Plant Bug, Adelphocoris lineolatus: Pheromone Composition and Antagonistic Effect of 1-Hexanol (Hemiptera: Miridae)". Journal of Chemical Ecology 47, n.º 6 (19 de abril de 2021): 525–33. http://dx.doi.org/10.1007/s10886-021-01273-y.

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AbstractThe sex pheromone composition of alfalfa plant bugs, Adelphocoris lineolatus (Goeze), from Central Europe was investigated to test the hypothesis that insect species across a wide geographical area can vary in pheromone composition. Potential interactions between the pheromone and a known attractant, (E)-cinnamaldehyde, were also assessed. Coupled gas chromatography-electroantennography (GC-EAG) using male antennae and volatile extracts collected from females, previously shown to attract males in field experiments, revealed the presence of three physiologically active compounds. These were identified by coupled GC/mass spectrometry (GC/MS) and peak enhancement as hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal. A ternary blend of these compounds in a 5.4:9.0:1.0 ratio attracted male A. lineolatus in field trials in Hungary. Omission of either (E)-2-hexenyl-butyrate or (E)-4-oxo-2-hexenal from the ternary blend or substitution of (E)-4-oxo-2-hexenal by (E)-2-hexenal resulted in loss of activity. These results indicate that this Central European population is similar in pheromone composition to that previously reported for an East Asian population. Interestingly, another EAG-active compound, 1-hexanol, was also present in female extract. When 1-hexanol was tested in combination with the ternary pheromone blend, male catches were reduced. This compound showed a dose-response effect with small doses showing a strong behavioral effect, suggesting that 1-hexanol may act as a sex pheromone antagonist in A. lineolatus. Furthermore, when (E)-cinnamaldehyde was field tested in combination with the sex pheromone, there was no increase in male catch, but the combination attracted both males and females. Prospects for practical application are discussed.

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Hoskovec, Michal, David Šaman y Aleš Svatoš. "Synthesis of (8E,10Z)-Tetradeca-8,10-dienal, Sex Pheromone of Horse Chestnut Leafminer (Cameraria ohridella), and All Its Geometrical Isomers". Collection of Czechoslovak Chemical Communications 65, n.º 4 (2000): 511–23. http://dx.doi.org/10.1135/cccc20000511.

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(8E,10Z)-Tetradeca-8,10-dienal (1a), sex pheromone of the horse chestnut leafminer (Cameraria ohridella; Lepidoptera, Gracillariidae), and its geometrical isomers (1b-1d) were efficiently synthesized using tetrakis(triphenylphosphine)palladium catalyzed cross-coupling reactions of alk-1-ynes or alkenyl alanes with corresponding vinyl iodides. The stereoisomeric purity of obtained tetradecadienals 1a-1d was higher than 95% (GC). Relative electroantennographic (EAG) activities of the prepared compounds 1a-1d elicited on male antennae supported the previously published identification of the C. ohridella sex pheromone.

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Batista-Pereira, Luciane G., João B. Fernandes, M. Fátima G. F. da Silva, Paulo C. Vieira, Odair C. Bueno y Arlene G. Corrêa. "Electrophysiological Responses of Atta sexdens rubropilosa Workers to Essential Oils of Eucalyptus and its Chemical Composition". Zeitschrift für Naturforschung C 61, n.º 9-10 (1 de octubre de 2006): 749–55. http://dx.doi.org/10.1515/znc-2006-9-1023.

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AbstractThe leaf-cutting ant Atta sexdens rubropilosa Forel, 1908 is the most harmful of the Eucalyptus pests, causing severe losses in wood production through defoliation. Various strategies have been tried and effort spent on the development of methods to control this pest, however no practical and environmentally acceptable one currently exists. In this work the chemical composition of the essential oil of seven Eucalyptus species was identified and the selectivity and sensitivity of antennal receptors of A. sexdens rubropilosa workers to the volatile compounds were determined using the electroantennographic technique (EAG and GC-EAD). Analysis by GC-EAD showed in E. cloesiana and E. maculata, respectively, seventeen and sixteen terpenes that elicited responses in ant workers’ antennae, indicating the potential role of the essential oils as allelochemicals that determine the choice of the foraging material.

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Zhang, Jiangchao, Jinjia Liu, Fei Gao, Min Chen, Yusuo Jiang, Huiting Zhao y Weihua Ma. "Electrophysiological and Behavioral Responses of Apis mellifera and Bombus terrestris to Melon Flower Volatiles". Insects 13, n.º 11 (22 de octubre de 2022): 973. http://dx.doi.org/10.3390/insects13110973.

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As important pollinators, honeybees and bumblebees present a pollination behavior that is influenced by flower volatiles through the olfactory system. In this study, volatile compounds from melon flowers were isolated and identified by headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC-MS), and their effects on Apis mellifera and Bombus terrestris were investigated by electroantennogram (EAG) and behavior tests (Y-tube olfactometer). The results showed that 77 volatile compounds were detected in melon flowers, among which the relative content of aldehydes was the highest (61.34%; 82.09%). A. mellifera showed a strong EAG response to e-2-hexenal, e-2-octenal, and 1-nonanal. B. terrestris showed a strong EAG response to e-2-hexenal, e-2-octenal, 2,5-dimethyl-benzaldehyde, benzaldehyde and benzenepropanal. In behavior tests, the volatiles with the highest attractive rate to A. mellifera were e-2-hexenal (200 μg/μL, 33.33%) and e-2-octenal (300 μg/μL, 33.33%), and those to B. terrestris were e-2-hexenal (10 μg/μL, 53.33%) and 2,5-dimethyl-benzaldehyde (100 μg/μL, 43.33%). E-2-hexenal and e-2-octenal were more attractive to A. mellifera than B. terrestris, respectively (10 μg/μL, 10 μg/μL, 200 μg/μL). In conclusion, the volatiles of melon flowers in facilities have certain effects on the electrophysiology and behavior of bees, which is expected to provide theoretical and technical support for the pollination of A. mellifera and B. terrestris in facilities.

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Xue, Jiaqi, Dongdong Ai, Xiangjun Xu, Changmei Wang, Xinji Jiang, Tana Han y Demtu Er. "Isolation and Identification of Volatile Substances with Attractive Effects on Wohlfahrtia magnifica from Vagina of Bactrian Camel". Veterinary Sciences 9, n.º 11 (16 de noviembre de 2022): 637. http://dx.doi.org/10.3390/vetsci9110637.

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Vaginal myiasis is one of the most serious parasitic diseases in Bactrian camels. At present, there are no reports on biological control measures of the disease. In this paper, the metabolomic analysis of vaginal secretions from susceptible and non-susceptible camels was performed by ACQUITY UPLC H-Class Ultra Performance Liquid Chromatograph. The results matched in 140 vaginal compounds. Methylheptenone, 1-octen-3-ol, and propyl butyrate and their mixtures were selected for gas chromatography-electroantennography (GC-EAD), electroantennography (EAG), behavioral experiments and trapping experiments of Wohlfahrtia magnifica (W. magnifica). Results showed that the W. magnifica had EAG responses to the three compounds, respectively. The EAG responses of female flies to different concentrations of methylheptenone were significantly different, but to the others had no significant difference, and there was no significant difference in the same compounds between the different sexes. Behavioral and trapping experiments showed that methylheptenone and 1-octen-3-ol have significant attraction to W. magnifica, but there was no significant difference to propyl butyrate. When methylheptenone and 1-octen-3-ol were mixed in different proportions, it was found that a mixture at the ratio of 1:1 and 0.5:1 had extremely significant and significant attraction, respectively, to both male and female W. magnifica. The study showed that, except for propyl butyrate, the higher the concentrations of the other two compounds, the stronger the attractivity to the W. magnifica, and a mixture at the ratio of 1:1 could enhance the attractivity to the W. magnifica.

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Batista-Pereira, Luciane G., Ellen M. Santangelo, Kathrin Stein, C. Rikard Unelius, Alvaro E. Eiras y Arlene G. Corrêa. "Electrophysiological Studies and Identification of Possible Sex Pheromone Components of Brazilian Populations of the Sugarcane Borer, Diatraea saccharalis". Zeitschrift für Naturforschung C 57, n.º 7-8 (1 de agosto de 2002): 753–58. http://dx.doi.org/10.1515/znc-2002-7-833.

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Virgin female gland extracts of sugarcane moth Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), from three locations in Brazil, have been analyzed. By GC-MS analysis and comparison of the chromatographic retention time of the components of the pheromone gland with those retention times of synthetic standards, we observed the presence of (Z)- hexadec-11-enal (1), hexadecanal (2), (9E,11Z)-hexadecadienal (4), (9Z,11Z)-hexadecadienal (5) and (9E,11E)-hexadecadienal (6), as minor components besides the major constituent (9Z,11E)-hexadecadienal (3) already reported. We found no variations in the composition of the gland extracts deriving from the three Brazilian populations and only two compounds, (Z)-hexadec-11-enal (1) and (9Z,11E)-hexadecadienal (3), elicited antennal responses (GCEAD). In electroantennography (EAG), however, pure compounds 1 and 3, a binary mixture containing 1 and 3, and a mixture containing all of the six synthetic compounds 1-6 elicited a depolarization in male antennae of D. saccharalis, without any statistically different delay. The EAG responses to the other isomers of 9,11-hexadecadienal were small and not significantly different from the control, except for the (9Z,11Z)-isomer (5) which showed an relatively strong electroantennal activity.

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Cheng, Jing, Lihong Yin, Shiping Zhou, Min Tang, Yunxian Li y Fazhong Yang. "The Inhibitory Effect of Powdery Mildew-Induced Volatiles from Rose on Host Selection Behavior of Beet Armyworm Moths (Lepidoptera: Noctuidae)". Journal of Entomological Science 57, n.º 1 (17 de diciembre de 2021): 96–113. http://dx.doi.org/10.18474/jes21-13.

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Abstract Plant-mediated indirect interactions (PMIIs) between phytopathogenic fungi and herbivorous insects on shared host plants occur in nature. Knowledge of PMIIs is critical in plant molecular breeding and integrated pest management. We studied the response and chemical mechanism of beet armyworm, Spodoptera exigua (Hübner), adults to rose plants, Rosa chinensis Jacquin, infected with rose powdery mildew, Podosphaera pannosa (Wallr.: Fr.) de Bary. Using gas chromatography-electroantennographic detection (GC-EAD) coupled with electroantennogram (EAG), we found that beet armyworm antennae responded to 8, 11, and 3 volatile organic compounds (VOCs) from noninfected roses, mildew-infected roses, and mildew alone, respectively. The EAG analyses showed 11 chemicals (e.g., limonene [1], 2-ethyl-1-hexanol [2], linalool [3], nonanal [4], (E)-β-caryophyllene [5], 1-dodecanol [7], nhexadecane [9], 1-hexadecanol [11], methyl palmitate [12], 1-octadecanol [14], and n-butyl hexadecanoate [15]) elicited electrophysiological responses of beet armyworm antennae with significant dose-response relationships (P < 0.05). The EAG responses to the three chemicals (3, 11, and 15) were greater than that to the reference chemical [i.e., (E)-2-hexenal] at 0.5, 5.0, and 50.0 mg/ml. Olfactory and ovipositional behavior assays indicated that three chemicals (2, 3, and 5) significantly attracted beet armyworm females and four chemicals (7, 11, 14, and 15) strongly repelled females. Chemicals 2, 3, and 5 from healthy roses appear to be responsible for the attraction of beet armyworm moths to healthy roses, whereas chemicals 7, 11, 14, and 15 from mildew-infected roses play key roles in inhibiting attraction of moths. VOCs from mildew alone did not attract or repel beet armyworm moths.

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Badji, Cesar Auguste, Jean Dorland, Lynda Kheloul, Dimitri Bréard, Pascal Richomme, Abdellah Kellouche, Claudio Roberto Azevedo de Souza, Antônio Lourenço Bezerra y Sylvia Anton. "Behavioral and Antennal Responses of Tribolium confusum to Varronia globosa Essential Oil and Its Main Constituents: Perspective for Their Use as Repellent". Molecules 26, n.º 15 (21 de julio de 2021): 4393. http://dx.doi.org/10.3390/molecules26154393.

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Essential oils of aromatic plants represent an alternative to classical pest control with synthetic chemicals. They are especially promising for the alternative control of stored product pest insects. Here, we tested behavioral and electrophysiological responses of the stored product pest Tribolium confusum, to the essential oil of a Brazilian indigenous plant, Varronia globosa, collected in the Caatinga ecosystem. We analyzed the essential oil by GC-MS, tested the effects of the entire oil and its major components on the behavior of individual beetles in a four-way olfactometer, and investigated responses to these stimuli in electroantennogram recordings (EAG). We could identify 25 constituents in the essential oil of V. globosa, with anethole, caryophyllene and spathulenole as main components. The oil and its main component anethole had repellent effects already at low doses, whereas caryophyllene had only a repellent effect at a high dose. In addition, the essential oil abolished the attractive effect of the T. confusum aggregation pheromone. EAG recordings revealed dose-dependent responses to the individual components and increasing responses to the blend and even more to the entire oil. Our study reveals the potential of anethole and the essential oil of V. globosa in the management of stored product pests.

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Batista-Pereira, Luciane G., Márcio G. dos Santos, Arlene G. Corrêa, João B. Fernandes, Alberto Arab, Ana Maria Costa-Leonardo, Célia R. R. C. Dietrich, Dilmar A. Pereira y Odair C. Bueno. "Cuticular Hydrocarbons of Heterotermes tenuis (Isoptera: Rhinotermitidae): Analyses and Electrophysiological Studies". Zeitschrift für Naturforschung C 59, n.º 1-2 (1 de febrero de 2004): 135–39. http://dx.doi.org/10.1515/znc-2004-1-226.

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Termites have become an important pest of Eucalyptus and Pinus reforestations, sugarcane and other cultures. An alternative for the control of this pest would be the use of attractive traps that take in account the social behavior of these insects. Diverse factors are important for the insects in the localization of the habitat and the choice of the food and specific odors can facilitate this. Studies referring to Heterotermes tenuis (Isoptera: Rhinotermitidae) are scarce. The objective of this work was to analyze the tergal cuticular extract of H. tenuis and determine the selectivity and sensitivity of its antennae to the components of this extract by electroantennography (EAG). The composition of the cuticular extract was determined by GC-MS analysis. The hydrocarbons found were restricted to linear alkanes, being most abundant C24 to C27 that comprises ca. 65% of the total. Olefins were not detected. EAG and behavioral test responses to the cuticular hydrocarbons were greater and significantly different from the control and the high selectivity of the antennae to the extract indicates its potential as chemical messenger. Cuticular hydrocarbons mixture is species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers or imagoes. Difference in the composition appears to relate with the type of habitat of specie.

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22

Kendra, Paul E., Wayne S. Montgomery, Nurhayat Tabanca, Elena Q. Schnell, Aimé Vázquez, Octavio Menocal, Daniel Carrillo y Kevin R. Cloonan. "Piperitone (p-Menth-1-En-3-One): A New Repellent for Tea Shot Hole Borer (Coleoptera: Curculionidae) in Florida Avocado Groves". Biomolecules 13, n.º 4 (6 de abril de 2023): 656. http://dx.doi.org/10.3390/biom13040656.

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The tea shot hole borer, Euwallacea perbrevis, has been recently established in Florida, USA, where it vectors fungal pathogens that cause Fusarium dieback in avocado. Pest monitoring uses a two-component lure containing quercivorol and α-copaene. Incorporation of a repellent into IPM programs may reduce the incidence of dieback in avocado groves, particularly if combined with lures in a push–pull system. This study evaluated piperitone and α-farnesene as potential repellents for E. perbrevis, comparing their efficacy to that of verbenone. Replicate 12-week field tests were conducted in commercial avocado groves. Each test compared beetle captures in traps baited with two-component lures versus captures in traps containing lures plus repellent. To complement field trials, Super-Q collections followed by GC analyses were performed to quantify emissions from repellent dispensers field-aged for 12 weeks. Electroantennography (EAG) was also used to measure beetle olfactory response to each repellent. Results indicated that α-farnesene was ineffective; however, piperitone and verbenone were comparable in repellency, achieving 50–70% reduction in captures, with longevity of 10–12 weeks. EAG responses to piperitone and verbenone were equivalent, and significantly greater than response to α-farnesene. Since piperitone is less expensive than verbenone, this study identifies a potential new E. perbrevis repellent.

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23

Jing, Xiaoyuan, Jintong Zhang, Youqing Luo, Shixiang Zong, Peihua Liu y Junxian Jia. "Identification and Field Evaluation of the Female Sex Pheromone of the Sand Salix Carpenterworm, Holcocerus arenicola Staudinger (Lepidoptera: Cossidae)". Zeitschrift für Naturforschung C 65, n.º 5-6 (1 de junio de 2010): 403–11. http://dx.doi.org/10.1515/znc-2010-5-614.

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Extracts of female sex pheromone glands of the sand Salix carpenterworm moth, Holcocerus arenicola, a serious pest of desert thicket, were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Based on comparison of retention times and mass spectra of synthetic standards, four compounds were identifi ed as cis-7-tetradecen-1-ol (Z7 - 14:OH), cis-5-tetradecen-1-yl acetate (Z5 - 14:OAc), cis-7-tetradecen- 1-yl acetate (Z7 - 14:OAc), and cis-9-hexadecen-1-yl acetate (Z9 - 16:OAc) with the ratio of 24:39:100:43. Electroantennographic (EAG) analyses of these standard chemicals and their analogues showed that Z7 - 14:OAc elicited the largest male EAG response, followed by Z5 - 14:OAc and Z9 - 16:OAc. In fi eld trials, traps baited with either Z7 - 14:OAc or Z5 - 14:OAc captured males while Z7 - 14:OH-, Z9 - 16:OAc- or solvent-baited traps caught no males. Z7 - 14:OAc as a single component was signifi cantly more attractive than Z5 - 14:OAc alone. The combination of Z7 - 14:OAc and Z5 - 14:OAc showed an evidently synergistic effect and attracted much more males than the individual compounds in the field. Addition of Z7 - 14:OH to the blend of Z7 - 14:OAc and Z5 - 14:OAc enhanced slightly the trap catches. We conclude that the major components of the sex pheromone of H. arenicola are Z7 - 14:OAc and Z5 - 14:OAc. Currently, a triangle trap baited with the synthetic compounds Z7 - 14:OAc, Z5 - 14:OAc, and Z7 - 14:OH in a 1:0.4:0.25 ratio at 825 μg/trap dosage can be effectively used to monitor the H. arenicola population level and catch the males within the desert regions in China.

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24

Babu, V. R., S. Satpathy y B. V. S. Reddy. "Identification and characterisation of female released sex pheromone components of jute semilooper, Anomis sabulifera Guenee (Lepidoptera: Noctuidae)". Journal of Environmental Biology 42, n.º 2 (1 de marzo de 2021): 254–64. http://dx.doi.org/10.22438/jeb/42/2/mrn-1501.

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Aim: Identification and characterization of female released sex pheromone components of jute semilooper, Anomis sabulifera Guenee (Lepidoptera: Noctuidae) from female pheromone gland extracts. Methodology: Electroantennogram (EAG) was carried for studying the antennal response; Gas Chromatography coupled with Electro antenna Detector (GC-EAD) was conducted for studying the antennal response of eluted compounds from female pheromone gland extract; Gas Chromatography and Mas Spectrophotometry (GC-MS) was conducted for characterization or getting complete profile of compounds present in the female pheromone gland extract based on retention times. Wind tunnel assay was conducted for studying the behavioural responses of eluted compounds from the female pheromone gland extract. Results: GC-MS profile of female pheromone gland extract revealed that the GC-EAD active region constituted (6Z,9Z)-heneicosadiene, (3Z,6Z,9Z)-heneicosatriene as active compounds. Preliminary wind tunnel studies for olfactory and behavioural responses showed blend of (6Z,9Z)-heneicosadiene (3 parts) + (3Z,6Z,9Z)-heneicosatriene (1 part) enticed 60% male adults. Interpretation: (6Z,9Z)-heneicosadiene and (3Z,6Z,9Z)-heneicosatriene are likely to be active pheromone components present in female sex pheromone glands. Blending of these two compounds in precise ratio can enhance the effectiveness of pheromone and can be used as effective strategy in jute IPM. Key words: Anomis sabulifera, Jute semilooper, Noctuidae, Sex pheromone, (6Z,9Z)-heneicosadiene, (3Z,6Z,9Z)-heneicosatriene

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Jintong, Zhang, Han Yan y Meng Xianzuo. "Sex Pheromone of the Carpenterworm, Holcocerus insularis (Lepidoptera, Cossidae)". Zeitschrift für Naturforschung C 56, n.º 5-6 (1 de junio de 2001): 423–29. http://dx.doi.org/10.1515/znc-2001-5-617.

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By means of thin-layer chromatography (TLC), electroantennogram (EAG), gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and field tests, (Z)-3-tetradecenyl acetate(Z3-14:Ac), (E)-3-tetradecen-1-ol(E3-14:OH), and (Z)-3-tetradecen-1-ol(Z3- 14:OH) at a ratio of 51:39:10 were identified from the female sex pheromone gland extracts of the carpenterworm, Holcocerus insularis Staudinger (Lepidoptera, Cossidae). The average amounts of Z3-14:Ac, E3-14:OH and Z3-14:OH in a single sex pheromone gland of calling moth were 7.29±2.72 ng, 5.72±2.43 ng and 1.44±0.56 ng, respectively. This is the first time that Z3-14:Ac was identified as a component of lepidopteran sex pheromone. Traps baited with rubber septa impregnated with Z3-14:Ac (500 μg / septum) were more effective than the traps baited with virgin female. The addition of the E3-14:OH and Z3-14:OH to rubber septa baited with Z3-14:Ac did not modify H. insularius male attraction, but E3-14:Ac slightly enhanced trap catch.

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26

Xiao, Dianzhao, Jiahui Liu, Yulong Liu, Yiwei Wang, Yidi Zhan y Yong Liu. "Exogenous Application of a Plant Elicitor Induces Volatile Emission in Wheat and Enhances the Attraction of an Aphid Parasitoid Aphidius gifuensis". Plants 11, n.º 24 (13 de diciembre de 2022): 3496. http://dx.doi.org/10.3390/plants11243496.

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It is well known that plant elicitors can induce plant defense against pests. The herbivore-induced plant volatile (HIPV) methyl salicylate (MeSA), as a signaling hormone involved in plant pathogen defense, is used to recruit natural enemies to protect wheat and other crops. However, the defense mechanism remains largely unknown. Here, the headspace volatiles of wheat plants were collected and analyzed by gas chromatography-mass spectrometry (GC−MS), gas chromatography with electroantennographic detection (GC−EAD) and principal component analysis (PCA). The results showed that exogenous application of MeSA induced qualitative and quantitative changes in the volatiles emitted from wheat plants, and these changes were mainly related to Carveol, Linalool, m-Diethyl-benzene, p-Cymene, Nonanal, D-limonene and 6-methyl-5-Hepten-2-one. Then, the electroantennogram (EAG) and Y-tube bioassay were performed to test the physiological and behavioral responses of Aphidius gifuensis Ashmesd to the active volatile compounds (p-Cymene, m-Diethyl-benzene, Carveol) that identified by using GC-EAD. The female A. gifuensis showed strong physiological responses to 1 μg/μL p-Cymene and 1 μg/μL m-Diethyl-benzene. Moreover, a mixture blend was more attractive to female A. gifuensis than a single compound. These findings suggested that MeSA could induce wheat plant indirect defense against wheat aphids through attracting parasitoid in the wheat agro-ecosystem.

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27

Torre Alvarez, Ruben, Diana Nolazco Cama y Lena Tellez Monzón. "Effect of the conditioning and ultrasound-microwave sequential technique on the yield, chemical and functional properties of the essential oils and hydrolats extracted from the leaves of Tagetes elliptica Smith". Scientia Agropecuaria 13, n.º 4 (29 de noviembre de 2022): 315–25. http://dx.doi.org/10.17268/sci.agropecu.2022.028.

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Thermal regulation and ultrasound affect the physical, chemical, and antioxidant properties of essential oils and hydrosols extracted by microwaves from the leaves of Tagetes elliptica S. (chincho). The leaves were conditioned by dehydration or freezing, then pre-treated with ultrasound for 15 or 30 minutes at 40 Hz to finally obtain the essential oil (AECH) and hydrolat (HCH) through microwave extraction (500 W and 30 minutes). Yields, phenolic content, antioxidant capacity, leaf structure by optical microscopy, and chemical composition by gas chromatography and mass spectrometry (GC-MS) were evaluated. The conditioning of the leaves by freezing and sonication for 30 minutes obtained the best performance, 8.86±0.1% and 67.40 ± 4.8%, phenolic content of 39.4±0.1 mg EAG/mL and 346.2 ± 13.6 mg EAG/mL, and antioxidant capacity of 35.7 μmol EqT/mg and 0.25 μmol EqT/mg equivalent, for AECH and HCH, respectively in every case. Structural damage of the leaves was observed due to the effect of the conditioning-ultrasound-microwave treatments, achieving a more significant release of bioactive compounds. The main compounds of the essential oil were tagetenones (49.2%), followed by cis-miroxide (14.5%), dihydrotagetone (13.9%), tagetone (9.8%) and ocimene (2.4%); the main compounds in the hydrolate were cis-myroxide (44.66%), followed by cis- tagetone (23.84%), trans-tagetone (12.24%), linalool oxide (5.48%) and dihydrotagetone (4.04%). The significant contribution of the present study is the extraction techniques and chemical profile of tagetes elliptica extracts.

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28

Dix, M. E. y E. W. Underhill. "SEX PHEROMONE OF RETINIA METALLICA (BUSCK) (LEPIDOPTERA: TORTRICIDAE): IDENTIFICATION AND FIELD STUDIES". Canadian Entomologist 120, n.º 8-9 (septiembre de 1988): 721–26. http://dx.doi.org/10.4039/ent120721-8.

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AbstractThe major sex pheromone component from female moths of Retinia metallica (Busck) was identified as Z7,E9-dodecadienyl acetate (Z7,E9-12:Ac) by a combination of electroantennographic (EAG), gas chromatographic (GC), and mass spectrometric analyses. In field tests, males of R. metallica were strongly attracted to Z7,E9-12:Ac. Addition of Z7,Z9-12:Ac, E7,Z9-12:Ac, Z7,E9-dodecadienol (Z7,E9-12:OH), andZ7-dodecenyl acetate (Z7-12:Ac) to Z7,E9-12:Ac did not significantly alter trap catch. However, the addition of E9-dodecenyl acetate (E9-12:Ac) and Z9-12:Ac reduced trap catch. Trap catch was affected by height of placement; traps placed in the upper third of the tree (6 m) caught significantly more males than traps placed at lower heights.

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29

Blažytė-Čereškienė, Laima, Vincas Būda, Violeta Apšegaitė, Sandra Radžiutė, Jurga Būdienė, Dominykas Aleknavičius y Raimondas Mozūraitis. "Sea Buckthorn Hippophae rhamnoides and Fruit Flies Rhagoletis batava: Search for Volatile Semiochemicals Involved in Pest Attraction". Horticulturae 8, n.º 2 (21 de febrero de 2022): 179. http://dx.doi.org/10.3390/horticulturae8020179.

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Rhagoletis batava (Diptera: Tephritidae), is the most important pest of Hippophae rhamnoides fruits. For detection and monitoring of R. batava, traps supplied with nonspecific attractants are used. Thus, new, more specific attractants for environment-friendly pest control are needed. Such attractants could be fruit-related semiochemicals that are involved in the host location by flies. Behavioural Y-olfactometer tests revealed that R. batava males were attracted to ripe fruit odour, while females preferred unripe and semi-ripe fruits. Thermal desorption gas chromatography-mass spectrometry (GC-MS) analysis revealed substantial quantitative and qualitative changes in volatiles between unripe and ripe fruits. In the unripe fruit emission, 41 volatile compounds were isolated, whereas 64 compounds were sampled from the ripe fruits. The total amount of volatiles increased five times during the fruit ripening. Gas chromatography-electroantennogram detection (GC-EAD) and GC-MS analyses of the fruit headspace volatiles revealed at least 26 compounds in unripe and 27 compounds in ripe fruits eliciting antennal responses of R. batava for both sexes. The fruits of these two ripening stages differed qualitatively in the single EAD-active compound only, i.e., 3-methylbutyl 2-methylpropionate. Esters were the most abundant volatiles, composing 84% and 93% of EAD-active compounds in the emissions of unripe and ripe fruits, respectively. Based on the persistent EAG responses, 17 compounds were selected as the most promising candidates for kairomone attractants of the sea buckthorn pest R. batava.

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30

Liu, Jinjia, Min Chen, Weihua Ma, Lifang Zheng, Bing Zhang, Huiting Zhao y Yusuo Jiang. "Composition of Strawberry Flower Volatiles and Their Effects on Behavior of Strawberry Pollinators, Bombus terrestris and Apis mellifera". Agronomy 13, n.º 2 (24 de enero de 2023): 339. http://dx.doi.org/10.3390/agronomy13020339.

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Strawberries are popular fruits around the world, and their yield and fruit quality rely on pollination by honey bees and bumblebee colonies. Both bee species have their own advantages in strawberry pollination. This study investigates the characteristic of strawberry (Fragaria × ananassa ‘Red Face’) flower volatiles and their effects on bee pollinators by (1) detecting the volatile compounds of strawberry flowers by polydimethylsiloxane (PDMS) combined gas chromatography-mass spectrometry (GC-MS), (2) determining whether Bombus terrestris or Apis mellifera showed antennae responses to certain compounds of strawberry flower volatiles by an electroantennography test (EAG), and (3) testing whether these compounds could elicit a corresponding behavioral response in bees. The results showed that (1) there were 38 chemical compounds in ‘Red Face’ volatiles with 7 types, most of which were known to be generally emitted by flowers but also have some compounds that have not been reported in strawberry flowers; (2) B. terrestris and A. mellifera had strong EAG responses to several compounds, respectively, especially to ethyl benzoate, (Z)-3-hexenyl propionate, (Z)-3-hexenyl acetate, benzeneacetaldehyde and melonal; and (3) both bee species showed significant avoidance behaviors to four tested compounds, especially the B. terrestris. Flower volatiles of strawberry ‘Red face’ were different from other strawberry varieties that have been reported; some of these electrophysiologically active compounds could cause antennal potential responses in bees, as well as behavioral responses. Our study supports the idea that strawberry flower volatiles are one of the factors influencing bee foraging decisions and provides a reference for formulating more reasonable bee pollination to improve strawberry fruit quality.

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31

Mancuello Chaparro, Claudia Raquel, Darío Benítez, Yanine Maubet, Enzo Cristaldo, Brenda Veloso, Francisco Ferreira y Michelle Campi. "Explorando las propiedades de la funga neotropical: perfil químico, actividades antioxidantes y antimicrobianas de Stiptophyllum erubescens (Berk.) Ryvarden". Steviana 14, n.º 2 (6 de diciembre de 2023): 5–16. http://dx.doi.org/10.56152/stevianafacenv14n2a1_2022.

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Striptophyllum erubescens es un basidiomiceto neotropical distribuido ampliamente en Sudamérica. Sin embargo, no se han encontrado registros de sus actividades biológicas, por lo que esta investigación constituye el primer estudio del perfil químico y las propiedades antioxidante y antimicrobiana de S. erubescens. Se obtuvo un extracto crudo etanólico y fracciones con disolventes de distintas polaridades (hexano, éter etílico, acetato de etilo y residuo acuoso) del basidioma salvaje. Se realizó la cuantificación de compuestos fenólicos y el ensayo de DPPH. Se analizó la composición de las fracciones con mayor concentración de fenoles y antioxidantes mediante GC-MS. Finalmente, la actividad antimicrobiana se evaluó mediante el test de discos de difusión. La mayor concentración de compuestos fenólicos y antioxidantes (172 ± 4 mg EAG g-1 y 185 mg EAA g-1, respectivamente) y actividad antioxidante (85%) se obtuvo en la fracción de acetato de etilo. Para las fracciones éter etílico y acetato de etilo, se determinaron por GC-MS alcanos y sus derivados, ácidos grasos, alcoholes grasos, fenoles, y un derivado del benzofurano. Se reporta por primera vez en un basidiomiceto el 5-metil-1-(2, 6, 6-trimetilciclohexa-2,4-dien-1-il) hexa-1,4-dien-3-ona. Ni el extracto crudo ni las fracciones presentaron actividad antimicrobiana.

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32

Cai, Lijun, Sarina Macfadyen, Baozhen Hua, Wei Xu y Yonglin Ren. "The Correlation between Volatile Compounds Emitted from Sitophilus granarius (L.) and Its Electrophysiological and Behavioral Responses". Insects 13, n.º 5 (20 de mayo de 2022): 478. http://dx.doi.org/10.3390/insects13050478.

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The granary weevil Sitophilus granarius (L.) is one of the most serious primary insect pests of stored products. When S. granarius present in grains, various volatile organic compounds are released as chemical signals which can be used to detect the insects. In this study, volatile chemical compounds released from S. granarius were analyzed using the headspace solid phase micro-extraction (HS-SPME) coupled with gas chromatography (GC)–mass spectrometry (MS) techniques. Two key compounds, 3-hydroxy-2-butanone and 1-pentadecene, were identified from mixed gender of S. granarius adults at high density. Moreover, both male and female adults showed dose-dependent electroantennography (EAG) responses to 3-hydroxy-2-butanone. In behavioral assays, S. granarius was attracted to 3-hydroxy-2-butanone at 0.001 µg/10 µL but repelled at 10 µg/10 µL or higher. S. granarius was consistently repelled by 1-pentadecene at concentrations at 0.001 and 1000 µg/10 µL. 3-hydroxy-2-butanone and 1-pentadecene have considerable potential to offer in the development of new approaches for the monitoring and management of this destructive stored grain insect pest.

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33

Affoué Delphine KOUASSI, Fatou Diane Micheline BAGUIA-BROUNE, Kohué Christelle Chantal N’GAMAN-KOUASSI, Janat Akhanovna MAMYRBEKOVA-BEKRO y Yves-Alain BEKRO. "Mineral and phenolic compositions, antioxidant activity and GC-MS analysis of the leaves of Anchomanes difformis (Blume) Engl. from Côte d’Ivoire". GSC Advanced Research and Reviews 10, n.º 1 (30 de enero de 2022): 145–55. http://dx.doi.org/10.30574/gscarr.2022.10.1.0035.

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The main objective of this study is to contribute to the valuation of Anchomanes difformis, a plant whose leaves are used for its oxytocic effect at the end of pregnancy and its use in the treatment of rheumatism in Côte d'Ivoire. The X-ray fluorescence spectrometer assay showed that the leaves of Anchomanes difformis contain (mg / 100g): K / 2061; P / 315.2; Ca / 1268; Na / 206.9; Mg / 653.8; Fe / 116.4; Cu / 0.79; Zn / 10.03 and Mn / 68.59. The quantitative spectrophotometric analysis of the phenolic compounds of the hydromethanolic crude extract of the leaves made it possible to determine the contents of total polyphenols (6.12 mg EAG / g), total flavonoids (mg EC / g), condensed tannins (0.637%) and hydrolyzable (0.312%). The evaluation of the antioxidant activity, measured by spectrophotometry against the stable free radical DPPH, revealed that the study extract (0.598 mg / ml) is less effective than vitamin C (0.032 mg / ml) taken as a reference. GC-MS analysis of the hydromethanolic extract revealed the existence of several phenolic compounds, the presence of which would be responsible for the therapeutic virtues of the leaves of Anchomanes difformis.

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34

Mergulhão, Naianny, Laisa Carolina Bulhões, Valdemir Silva, Ilza Fernanda Rodrigues, Irinaldo Basílio Júnior y João Araújo Júnior. "Development of Syzygium aromaticum (L.) essential oil encapsulates by ionic gelification and evaluation of antioxidant activity". Concilium 24, n.º 8 (1 de mayo de 2024): 339–57. http://dx.doi.org/10.53660/clm-3306-24h24.

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The objective of this work was to develop a product capable of protecting Syzygium aromaticum (clove) essential oil against high volatility. Clove oil (CEO) was encapsulated in alginate by ionic gelation with subsequent freeze-drying. Characterization was carried out by GC/MS, TGA/DSC and antioxidant (DPPH), and total phenol (Folin-Ciocalteau) analysis. Eugenol was the majority (81.5%) and the encapsulation efficiency varied between 14.0%+0.96 (F1: 1.0% alginate) and 9.8%+0.35 (F2: 2.0% alginate) in wet encapsulates, and 23.5%+0.14 (LF1: 1.0% alginate) and 16.9%+0.16 (LF2: 2.0% alginate) in freeze-dried encapsulates. The total phenol content reached 714.8+0.97 EAG g-1 in LF1, with strong inhibition of the DPPH radical (71.4%). Freeze-drying provided a higher percentage of active ingredients per gram of encapsulated and it was possible to identify high thermal stability in LF1 (mass loss: 81.8%; 258.9 °C) compared to wet encapsulates (mass loss: 86.5%; 65.8°C). The use of the lowest concentration of alginate seems to have been favorable. In this way, the accessible technology used allows preserving the content and properties of the CEO, offering a basis for new encapsulated research.

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35

Carson, C., M. A. Birkett, J. G. Logan, K. Mawa, H. V. Pates, J. A. Pickett, R. T. Rwegoshora, P. K. Tungu y M. M. Cameron. "Novel use of stir bar sorptive extraction (SBSE) as a tool for isolation of oviposition site attractants for gravid Culex quinquefasciatus". Bulletin of Entomological Research 100, n.º 1 (23 de marzo de 2009): 1–7. http://dx.doi.org/10.1017/s0007485309006701.

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AbstractMosquitoes such as Culex quinquefasciatus Say (Diptera: Culicidae) are important vectors of organisms that cause disease in humans. Research into the development of effective standardized odour baits for blood-fed females (oviposition attractants), to enable entomological monitoring of vector populations, is hampered by complex protocols for extraction of physiologically active volatile chemicals from natural breeding site water samples, which have produced inconsistent results. Air entrainment and solvent extraction are technically demanding methods and are impractical for use in resource poor environments where mosquito-borne disease is most prevalent. This study reports the first use of a simple, robust extraction technique, stir bar sorptive extraction (SBSE), to extract behaviourally active small lipophilic molecules (SLMs) present in water samples collected from Cx. quinquefasciatus breeding sites in Tanzania. Extracts from a pit latrine and from a cess pool breeding site attracted more gravid Cx. quinquefasciatus in pair choice bioassays than control extracts, and coupled gas chromatography-electroantennography (GC-EAG) allowed tentative identification of 15 electrophysiologically active chemicals, including the known oviposition attractant, skatole (3-methylindole). Here, we have demonstrated, using simple pair choice bioassays in controlled laboratory conditions, that SBSE is effective for the extraction of behaviourally and electrophysiologically active semiochemicals from mosquito breeding site waters. Further research is required to confirm that SBSE is an appropriate technique for use in field surveys in the search for oviposition cues for Cx. quinquefasciatus.

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Xia, Shike, Tao Zhang, Livy Williams, Yizhong Yang y Yanhui Lu. "Buckwheat Flower Volatiles Attract Peristenus spretus and Enhance Its Field-Level Parasitism of Apolygus lucorum". Plants 12, n.º 8 (15 de abril de 2023): 1658. http://dx.doi.org/10.3390/plants12081658.

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Volatile compounds play indispensable roles in the interactions among host plants, herbivores and natural enemies. Previous studies showed that the addition of buckwheat strips in cotton fields could attract Peristenus spretus, the dominant parasitoid of Apolygus lucorum, and enhance its parasitic activity. Through the combined analysis of Y-tube olfactometer, solid-phase microextraction (SPME), gas chromatography-mass spectrometer (GC-MS) and electroantennography (EAG), we found that male and female P. spretus responded to compounds present in buckwheat flowers. The five major components of buckwheat flowers, cis-3-hexenyl acetate (Z3HA), 4-methylanisole, 4-oxoisophorone, p-methylphenol and 2-ethylhexyl salicylate, all had a significant attraction to P. spretus adults and led to positive electroantennogram responses, especially for 10 mg/mL 4-oxoisophorone, indicating the components played a key role in the selection behavior of P. spretus to buckwheat flowers. Additionally, field trials showed that the five volatiles could significantly increase the parasitism by P. spretus. Our study screened the key active components of buckwheat flower volatiles that have an attractive effect on P. spretus, revealing its behavioral selection mechanism and emphasizing the important role of plant volatiles on host selection and parasitism of parasitic wasps, providing a theoretical basis for the development of attractants for P. spretus and the reduction of pesticides in the field to promote conservation biological control (CBC) of A. lucorum.

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Bustos-Cortés, Jenifer J., Rosa C. Aldana-De la Torre, Anuar Morales-Rodríguez, Carolina Chegwin-Angarita y Alicia Romero-Frías. "Sexual behavior and chemical signaling in Opsiphanes cassina (Lepidoptera: Nymphalidae)". Chemoecology 33, n.º 6 (diciembre de 2023): 161–75. http://dx.doi.org/10.1007/s00049-023-00393-z.

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AbstractBehavior modification using chemical stimuli is a promising tactic for integrated management of lepidopteran pests. Therefore, this approach was evaluated for the management of the butterfly Opsiphanes cassina Felder 1862, a defoliating pest in oil palm plantations. To achieve this aim, we observed adults’ sexual behavior under laboratory conditions and identified glandular structures in the abdomen and hind wings of males that are associated with the production of sexual pheromones in taxonomically related insects. It was also determined that male calls to females occur at 18:00 h when they fill their glandular structures, tremble, and make abdominal movements while possibly releasing pheromones. The hairpencils of the hind wings are also exposed during this time. Furthermore, the analysis using Gas Chromatography-Mass Spectrometry (GC–MS) on the samples obtained by Solvent Assisted Extraction (SAE) revealed the identification of three male-specific volatile organic compounds (VOCs), including (E)-nerolidol, vanillin, and (Z)-7-heptadecene. The Electroantennographic (EAG) evaluation demonstrated that females respond to the compounds, indicating their likely involvement in intraspecific interactions of the species. However, the behavioral evaluation did not confirm their attractive effect under the conditions employed. Nevertheless, the identified male-specific semiochemicals could be an alternative for inclusion in integrated pest management (IPM) of this pest in oil palm crops. Therefore, it is recommended to evaluate them under field conditions.

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Almeida, Camila Alexandre Cavalcante de, Fernanda Da Silva Gonçalves, Matheus Barros Rodrigues, Anderson Bruno Anacleto de Andrade, Jakeline Maria dos Santos, Mariana Oliveira Breda y Antônio Euzébio Goulart Santana. "Compostos orgânicos voláteis (COVs) cuticulares em Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae)". Ciência Florestal 31, n.º 2 (1 de junio de 2021): 948–58. http://dx.doi.org/10.5902/1980509844521.

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A lagarta-parda do eucalipto, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), vem sendo relatada de forma significativa em povoamentos florestais. A importância econômica de Thyrinteina arnobia para o setor florestal na atualidade evidencia a necessidade da consolidação do Manejo Integrado de Pragas Florestais (MIP Floresta), incluindo métodos de monitoramento e controle através de semioquímicos, como o emprego de feromônios. Os compostos químicos voláteis (COVs) em substâncias cuticulares de insetos podem contribuir na regulação da interação entre os indivíduos, sendo objeto de estudo da ecologia química. Dessa forma, objetivou-se realizar uma prospecção dos compostos orgânicos voláteis (COVs) cuticulares em Thyrinteina arnobia e avaliar o papel desses compostos como possíveis feromônios de curta distância. Para o estudo químico de substâncias feromonais, foi realizada a extração de compostos cuticulares (asas e pernas) em Thyrinteina arnobia de machos e fêmeas. Os extratos obtidos foram analisados por cromatografia gasosa com detector de ionização de chamas (GC-FID). Foi realizado um espectro de ação por meio da eletroantenografia acoplada à cromatografia gasosa (CG-EAG) dos extratos de asas e pernas de fêmeas virgens sobre a antena de machos de Thyrinteina arnobia. Contudo, não foi possível observar diferença significativa nas respostas das antenas de machos a nenhum dos estímulos oferecidos. Assim, é possível inferir que Thyrinteina arnobia não faz uso de compostos cuticulares para reconhecimento a curta distância, sendo necessários estudos complementares de comportamento sexual, incluindo observação de corte e cópula.

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Barbosa-Cornelio, Ricardo, Fernando Cantor, Ericsson Coy-Barrera y Daniel Rodríguez. "Tools in the Investigation of Volatile Semiochemicals on Insects: From Sampling to Statistical Analysis". Insects 10, n.º 8 (6 de agosto de 2019): 241. http://dx.doi.org/10.3390/insects10080241.

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The recognition of volatile organic compounds (VOCs) involved in insect interactions with plants or other organisms is essential for constructing a holistic comprehension of their role in ecology, from which the implementation of new strategies for pest and disease vector control as well as the systematic exploitation of pollinators and natural enemies can be developed. In the present paper, some of the general methods employed in this field are examined, focusing on their available technologies. An important part of the investigations conducted in this context begin with VOC collection directly from host organisms, using classical extraction methods, by the employment of adsorption materials used in solid-phase micro extraction (SPME) and direct-contact sorptive extraction (DCSE) and, subsequently, analysis through instrumental analysis techniques such as gas chromatography (GC), nuclear magnetic resonance (NMR) and mass spectrometry (MS), which provide crucial information for determining the chemical identity of volatile metabolites. Behavioral experiments, electroantennography (EAG), and biosensors are then carried out to define the semiochemicals with the best potential for performing relevant functions in ecological relationships. Chemical synthesis of biologically-active VOCs is alternatively performed to scale up the amount to be used in different purposes such as laboratory or field evaluations. Finally, the application of statistical analysis provides tools for drawing conclusions about the type of correlations existing between the diverse experimental variables and data matrices, thus generating models that simplify the interpretation of the biological roles of VOCs.

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Smid, Hans M., Joop J. A. van Loon, Maarten A. Posthumus y Louise E. M. Vet. "GC-EAG-analysis of volatiles from Brussels sprouts plants damaged by two species of Pieris caterpillars: olfactory receptive range of a specialist and a generalist parasitoid wasp species". Chemoecology 12, n.º 4 (noviembre de 2002): 169–76. http://dx.doi.org/10.1007/pl00012665.

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Fujiwara-Tsujii, N., H. Yasui, S. Wakamura, F. Mochizuki y N. Arakaki. "Age-dependent changes in the ratio of (R)- and (S)-2-butanol released by virgin females of Dasylepida ishigakiensis (Coleoptera: Scarabaeidae)". Bulletin of Entomological Research 102, n.º 6 (10 de julio de 2012): 730–36. http://dx.doi.org/10.1017/s0007485312000363.

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AbstractThe females of the white grub beetle, Dasylepida ishigakiensis, release two enantiomers of 2-butanol, (R)-2-butanol and (S)-2-butanol. The ratio describing the relative proportions of these two enantiomers (R/S ratio) has not yet been investigated. (R)-2-Butanol has been shown to attract males in laboratory and field experiments, whereas (S)-2-butanol tends to inhibit them. To determine the R/S ratio of the 2-butanol emitted by virgin females, we collected 2-butanol from young (53 days old), mature (63 days old) and old females (73 days old) using water, extracted with an SPME fibre and subsequently injected into GC-MS. The major component of the 2-butanol emitted by the young females was (R)-2-butanol, but as the females aged, the component ratio favoured (S)-2-butanol. Young females released an 80:20 mixture of (R)- and (S)-2-butanol, whereas old females released a 45:55 mixture. The EAG response of male antennae to a 50:50 ratio (racemic mixture) showed a similar dose-response curve to that of (R)-2-butanol. The male orientation responses to (R)-2-butanol decreased when the relative proportion of (S)-2-butanol increased. An inhibitory and/or masking effect of (S)-2-butanol on male orientation behaviour was also observed in the flight tunnel assay. These results suggest that males are more strongly attracted to young females than to old females. We also discuss the possibility of using 2-butanol isomers as a control or monitoring agent for this insect.

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Bhowmik, Biswanath, Udipta Chakraborti, Alivia Mandal, Bishwajeet Paul y Kakali Bhadra. "Attraction of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) to Host Plant Cucurbita maxima Duchesne (Cucurbitaceae) Volatiles". Agronomy 12, n.º 11 (26 de octubre de 2022): 2640. http://dx.doi.org/10.3390/agronomy12112640.

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The volatiles extracted by the dynamic headspace collection system from the undamaged and conspecific damaged Cucurbita maxima were analyzed by Gas chromatography–mass spectrometry (GC-MS). The olfactory responses of antennal chemosensilla by male and female A. foveicollis towards the plant volatiles were studied by electroantennography (EAG), while the behavioral responses were analyzed by olfactometer bioassay under laboratory conditions. Scanning electron microscopic study revealed the predominance of antennal olfactory sensilla of seven different types with four types of mechanosensilla. The antennae are sexually dimorphic, with differences in density of the chemosensillae present in the apical band region of segment IX, called the circumferential band, being higher in the females. Female antennae showed maximum peak amplitudes for 2-methyl phenol (at 10 mg/mL), followed by 1,4, dimethoxybenzene (at 5 mg/mL), while male antennae showed maximum amplitudes for heneicosane (at 5 mg/mL). Y-tube bioassays revealed maximum attractiveness towards 1,4, dimethoxy benzene that decreased progressively across heneicosane, pentacosane, tetradecane, ethyl benzene, D-limonene, nonadecane, eicosane, nonanal, decanal, α-pinene, phytol and benzaldehyde in females. However, male species were more responsive towards heneicosane, followed by 1,4 dimethoxybenzene, while the responses to pentacosane and tetradecane were equal, followed by equal responses to decanal, ethyl benzene and nonadecane, and thereafter, a progressively reducing response was observed towards α-pinene, eicosane, nonanal, D-limonene, phytol and benzaldehyde. The study assists in understanding the role of olfaction by A. foveicollis in the host plant Cucurbita maxima by listing compounds that act as potential kairomones for the beetle, and can be expected to facilitate development of an eco–friendly trap and/or by attracting the natural enemies for control of the pest.

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Liu, Fu, Chengxu Wu, Sufang Zhang, Xiangbo Kong, Zhen Zhang y Pingyan Wang. "Initial Location Preference Together with Aggregation Pheromones Regulate the Attack Pattern of Tomicus brevipilosus (Coleoptera: Curculionidae) on Pinus kesiya". Forests 10, n.º 2 (12 de febrero de 2019): 156. http://dx.doi.org/10.3390/f10020156.

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Research Highlights: We found that the initial attack location together with the aggregation pheromones played an important role in mediating the aggressive behavior of T. brevipilosus on P. kesiya. Background and Objectives: T. brevipilosus was identified as an aggressive species, which possesses the ability to kill live, healthy P. kesiya. In this scenario, we study the top-down attack pattern of T. brevipilosus on P. kesiya during the entirety of the reproductive period. Materials and Methods: We investigated the phenology of trunk attack on P. kesiya over a period of three years in Pu’er City, China. The hindguts extracts of the females and males T. brevipilosus were analyzed by coupled gas chromatography-mass spectrometry (GC-MS). The candidate aggregation pheromone compounds of T. brevipilosus were determined through electrophysiology experiments (electroantennographic detection, EAD and electroantennography, EAG), laboratory olfactometer bioassays, and field trapping. Results: we found that the pioneer beetles preferentially infested the crown of P. kesiya at the early stage of attack following spring flight with the later arriving beetles selectively attacking the lower area of the trunk to avoid intraspecific competition and better utilize limited resources, which exhibits a top-down attack pattern. During gallery initiation, the beetles release aggregation pheromones to attract conspecifics to conduct a mass attack. The chemical analyses indicated that the hindgut extracts of gallery-initiating beetles contained a larger amount of myrtenol, cis-verbenol, trans-verbenol, and verbenone. Myrtenol and trans-verbenol were identified as candidate aggregation pheromone compounds. In addition, a blend of these two components with S-(−)-α-pinene and S-(−)-β-pinene attracted more T. brevipilosus individuals in a field bioassay. Conclusions: We concluded that the preference for the initial attack location together with the aggregation pheromones played an important role in mediating the top-down attack pattern of T. brevipilosus on P. kesiya.

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Mariscal-Lucero, Samantha Del Rocío, Martha Rosales-Castro, Vicente Sánchez-Monsalvo y José Amador Honorato-Salazar. "Evaluación de fenoles y limonoides en hojas de Cedrela odorata (Meliaceae) de una plantación experimental establecida en Tezonapa Veracruz, México". Revista de Biología Tropical 63, n.º 2 (1 de diciembre de 2014): 545. http://dx.doi.org/10.15517/rbt.v63i2.15405.

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Cedrela odorata (Meliaceae) is a native timber tree to Tropical America, known for its high-quality wood, unfortunately, plantations of this species are severely attacked by Hypsipyla grandella. The attraction or repellency of this pest is related to secondary metabolites such as phenols and limonoids (triterpenes); therefore, it is important to study these compounds to understand the phytochemical phenomena behind this problem. With this aim, the concentration of total phenols and limonoides was evaluated in C. odorata leaves from a plantation established in Tezonapa Veracruz, Mexico. For this, a total of 66 tree leaves samples, from seven sites, were analyzed. Phenols and limonoids concentration showed significant differences not only among different provenances, but also among individual trees of the same site (Tukey, p≤0.05). Phenols concentration was variable and in the range from 49 to 223mg EAG/g e for total phenols, from 7 to 158mg EC/g e for flavonoids and from 4 to 104mg EC/g e for proanthocyanidins. Limonoids concentration was also variable, ranging between 227 and 748mg EL/g e. A major compound was found by High-Performance Liquid Chromatography with Ultraviolet Diode Array Detection (HPLC-UV-DAD), which corresponded to a flavonol kaempferol glycoside derivative; additionally, a flavanol catechin was also detected at low concentrations. GC–MS allowed the identification of the sesquiterpenoids β-elemene, E-caryophyllene, aromadendrene, α-humulene, γ-cadinene, D-germacrene, bicyclogermacrene, and the poly terpenoids D-α-tocopherol and β-sitosterol. Our results suggest that the evaluation of phenols may play an important role as a selection parameter for improvement and conservation programs, if they are complemented with conventional breeding practices.

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Priyanto, Jepri Agung, Egiyanti Nur Widhia Hening, Vera Permatasari, Muhammad Eka Prastya, La Ode Abdul Fajar Hasidu y Gian Primahana. "Antioxidant and Cytotoxic Properties of Extract from Soil Bacteria Isolated from Muna Island, Southeast Sulawesi". Jurnal ILMU DASAR 25, n.º 1 (23 de enero de 2024): 7. http://dx.doi.org/10.19184/jid.v25i1.39244.

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Soil bacteria could be the promising source of secondary metabolites with diverse pharmacological activities. Bacteria coded as P1 and M7 were isolated from soil obtained from Muna Island, Southeast Sulawesi. This research aimed to evaluate the antioxidant activity, cytotoxic property, and identify the chemical profile of the extract derived from soil bacteria P1 and M7. Based on 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, extract derived from P1 isolate was moderately active against ABTS free radical with IC50 of 126.22±10.82 µg/mL, and less active on DPPH (IC50: 721.95±16.59 µg/mL), while M7 extract was less active towards DPPH and ABTS. Interestingly, these extracts in the concentration of 100 µg/mL were cytotoxic to breast cancer cell (MCF-7), as tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. MCF-7 viability was decreased up to 69.83±1.46 % and 61.49±0.76 % after treated with P1 and M7 extract, respectively. The extracts were also induced membrane disruption and apoptosis of MCF-7 cells. The extracts contained phenol (9.52±0.22 and 10.41±0.09 mg EAG/g extract, for P1 and M7, respectively) and flavonoids (9.16±0.16 and 9.29±0.24 mg EQ/g extract, for P1 and M7, respectively). According to Gas Chromatography Mass Spectrometry (GC-MS) analysis, Pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) that previously well known as antioxidant and cytotoxic compounds, were found in the M7 and P1 extract. This compound may play a vital role in the radical scavenging and cytotoxic properties of P1 and M7 extracts. The results of this study indicate that P1 and M7 extracts could be the potential source of antioxidant and cytotoxic compounds and need to be further developed for pharmaceutical use.

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Xu, Danping, Qianqian Qian y Zhihang Zhuo. "The different responses of Batocera horsfieldi adults to Juglans regia bark and leaf volatile compounds". Entomologia Experimentalis et Applicata, 14 de marzo de 2024. http://dx.doi.org/10.1111/eea.13422.

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AbstractBatocera horsfieldi (Hope) (Coleoptera: Cerambycidae) is an important pole borer pest. It causes serious harm to various hosts, particularly Juglans regia L. (Juglandaceae). In this study, headspace solid‐phase microextraction (HS‐SPME), gas chromatography–mass spectrometry (GC–MS), and electroantennogram (EAG) responses were combined to examine the mechanism by which B. horsfieldi adults locate their host, J. regia. The results showed that J. regia contained 65 volatile compounds in all, with 36 and 42 volatile substances in bark and leaves, respectively. Moreover, terpenes accounted for the largest relative content among the volatile compounds of bark and leaves, 43.4 and 78.9%, respectively. Ten of 19 selected volatile components elicited significant EAG responses in adult B. horsfieldi, which indicated that the pest may prefer certain volatile compounds when selecting a host. Sex and volatile concentration affected the responses of B. horsfieldi. Male adults had the strongest EAG responses to 1‐octen‐3‐ol, whereas female adults had the strongest EAG responses to linalool. Host selection in B. horsfieldi was somewhat positively associated with the concentrations of the effective volatile compounds in the host. Furthermore, B. horsfieldi showed varying preferences for isomers. This work provided data support for the development of insect attractants, and laid a theoretical foundation for the ecological protection of local forestry.

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Pistillo, Onofrio Marco, Ilaria D’Isita, Antonella Di Palma y Giacinto Salvatore Germinara. "Identification of the Sex Pheromone of the Asparagus Moth, Parahypopta Caestrum (Lepidoptera, Cossidae)". Journal of Chemical Ecology, 20 de mayo de 2024. http://dx.doi.org/10.1007/s10886-024-01504-y.

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AbstractChemical, electrophysiological, and field trapping experiments were carried out to identify the female-produced sex pheromone of the asparagus moth, Parahypopta caestrum, a very serious pests of asparagus cultivations in southern Europe. Gas chromatography coupled with mass spectrometry and electroantennogram detection (GC-MS-EAD) analysis of hexane and solid-phase microextraction (SPME) extracts of sex pheromone glands of calling females consistently detected four compounds eliciting EAG responses in male moth antennae. According to their GC retention times, mass spectra, and comparative EAG analyses with reference standards, these EAD-active compounds were identified as (Z)-9-tetradecenol (Z9-14:OH), (Z)-5-tetradecenyl acetate (Z5-14:Ac), (Z)-7-tetradecenyl acetate (Z7-14:Ac), and (Z)-9-tetradecenyl acetate (Z9-14:Ac), respectively. In the SPME extracts from the head-space of individual abdominal tips, Z9-14:Ac, Z5-14:Ac, Z7-14:Ac, and Z9:14 OH were detected in the ratio of 82:9:5:4. In EAG dose-response experiments, Z9-14:Ac was the strongest antennal stimulant at different doses tested. In field trapping experiments, Z9-14:Ac, Z7-14:Ac, and Z5-14:Ac proven to be essential for male attraction and a their 85:5:10 blend loaded onto green rubber septum dispensers was significantly more effective than single-, two-, and any other three-component blend of these compounds. The addition of Z9-14:OH to the optimal blend resulted in a significant reduction of male catches. The attractive blend here identified allowed for an effective and accurate monitoring of P. caestrum flight activity in southern Italy.

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Miano, Raphael Njurai, Pascal Mahukpe Ayelo, Richard Musau, Ahmed Hassanali y Samira A. Mohamed. "Electroantennogram and machine learning reveal a volatile blend mediating avoidance behavior by Tuta absoluta females to a wild tomato plant". Scientific Reports 12, n.º 1 (27 de mayo de 2022). http://dx.doi.org/10.1038/s41598-022-13125-0.

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AbstractTomato cultivation is threatened by the infestation of the nocturnal invasive tomato pinworm, Tuta absoluta. This study was based on field observations that a wild tomato plant, Solanum lycopersicum var. cerasiforme, grown in the Mount Kenya region, Kenya, is less attacked by T. absoluta, unlike the cultivated tomato plants like S. lycopersicum (var. Rambo F1). We hypothesized that the wild tomato plant may be actively avoided by gravid T. absoluta females because of the emission of repellent allelochemical constituents. Therefore, we compared infestation levels by the pest in field monocrops and intercrops of the two tomato genotypes, characterized the headspace volatiles, then determined the compounds detectable by the insect through gas chromatography-linked electroantennography (GC-EAG), and finally performed bioassays using a blend of four EAG-active compounds unique to the wild tomato. We found significant reductions in infestation levels in the monocrop of the wild tomato, and intercrops of wild and cultivated tomato plants compared to the monocrop of the cultivated tomato plant. Quantitative and qualitative differences were noted between volatiles of the wild and cultivated tomato plants, and between day and night volatile collections. The most discriminating compounds between the volatile treatments varied with the variable selection or machine learning methods used. In GC-EAG recordings, 16 compounds including hexanal, (Z)-3-hexenol, α-pinene, β-myrcene, α-phellandrene, β-phellandrene, (E)-β-ocimene, terpinolene, limonene oxide, camphor, citronellal, methyl salicylate, (E)-β-caryophyllene, and others tentatively identified as 3,7,7-Trimethyl-1,3,5-cycloheptatriene, germacrene D and cis-carvenone oxide were detected by antennae of T. absoluta females. Among these EAG-active compounds, (Z)-3-hexenol, α-pinene, α-phellandrene, limonene oxide, camphor, citronellal, (E)-β-caryophyllene and β-phellandrene are in the top 5 discriminating compounds highlighted by the machine learning methods. A blend of (Z)-3-hexenol, camphor, citronellal and limonene oxide detected only in the wild tomato showed dose-dependent repellence to T. absoluta females in wind tunnel. This study provides some groundwork for exploiting the allelochemicals of the wild tomato in the development of novel integrated pest management approaches against T. absoluta.

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Magsi, Fida Hussain, Xiaoming Cai, Zongxiu Luo, Zhaoqun Li, Lei Bian, Chunli Xiu, Nanxia Fu, Jianlong Li, David R. Hall y Zongmao Chen. "Identification, synthesis, and field evaluation of components of the female‐produced sex pheromone of Helopeltis cinchonae (Hemiptera: Miridae), an emerging pest of tea". Pest Management Science, 16 de abril de 2024. http://dx.doi.org/10.1002/ps.8129.

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AbstractBACKGROUNDHelopeltis cinchonae (Hemiptera: Miridae) is a major pest of tea plantations in Asia. Conventional control of pests with pesticides is unsustainable. Therefore, safe and eco‐friendly alternatives, such as pheromones, are required to manage the pest.RESULTSIn GC–EAD analyses of whole‐body extracts of virgin female H. cinchonae, two compounds elicited EAG responses from male antennae. These were identified as hexyl (R)‐3‐acetoxybutyrate and (R)‐1‐acetoxy‐5‐butyroxyhexane using GC–MS analysis compared to synthetic compounds. This is the first study to report 1‐acetoxy‐5‐butyroxyhexane as an insect pheromone component. The synthetic compounds elicited dose‐dependent EAG responses from the antennae of male H. cinchonae. In two field trapping experiments, the individual compounds were highly attractive to male H. cinchonae when dispensed from polyethylene vials. However, higher catches were obtained with blends of the two compounds in a 1:10 ratio. The blend of racemic compounds was as attractive as the blend of (R)‐enantiomers.CONCLUSIONSWe reported that 1‐Acetoxy‐5‐butyroxyhexane and hexyl 3‐acetoxybutyrate are components of the female‐produced sex pheromone of H. cinchonae, but further work is required on the blend and loading of pheromone and on trap design to provide an optimized system for monitoring and control of this pest. The results may also facilitate the identification of the pheromones of other Helopeltis species, which are major pests in many crops.This article is protected by copyright. All rights reserved.

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Bray, Daniel P., David R. Hall, Steven J. Harte, Dudley I. Farman, Meghan A. Vankosky y Boyd A. Mori. "Components of the Female Sex Pheromone of the Newly-Described Canola Flower Midge, Contarinia brassicola". Journal of Chemical Ecology, 30 de junio de 2022. http://dx.doi.org/10.1007/s10886-022-01369-z.

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Abstract The canola flower midge, Contarinia brassicola Sinclair (Diptera: Cecidomyiidae), is a newly-described species that induces galls on canola, Brassica napus Linnaeus and Brassica rapa Linnaeus (Brassicaceae). Identification of the sex pheromone of C. brassicola is essential to developing monitoring tools to elucidate the geographic range and hosts of this new pest, and the extent to which it threatens the $30 billion Canadian canola industry. The aim of this study was to identify and synthesize the female-produced sex pheromone of C. brassicola and demonstrate its effectiveness in attracting males to traps in the field. Two peaks were identified through GC-EAG analysis of female-produced volatiles which elicited electrophysiological responses in male antennae. These peaks were initially characterized through GC–MS and synthesis as 2,7-diacetoxynonane (major component) and 2-acetoxynonane (minor component), and the racemic compounds elicited EAG responses in male antennae. All four stereoisomers of 2,7-diacetoxynonane were synthesized and the naturally-produced compound was shown to be primarily the (2R,7S)-isomer by analysis on an enantioselective GC column, with a small amount of (2R,7R)-2,7-diacetoxynonane also present. The configuration of the minor component could not be determined because of the small amount present, but this was assumed to be (2R)-2-acetoxynonane by comparison with the configuration of the other two components. In field trials, none of the four stereoisomers of 2,7-diacetoxynonane, presented individually or as a racemic mixture, was attractive to male C. brassicola. However, dispensers loaded with a 10 µg:1 µg blend of (2R,7S)- and (2R,7R)-2,7-diacetoxynonane caught large numbers of male C. brassicola and significantly more than other blends tested. The addition of 0.5 µg of (2R)-2-acetoxynonane to this blend further increased the number of males caught. In future work, we will seek to identify the optimum trapping protocol for the application of the pheromone in monitoring and surveillance.

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