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1.
J Insect Sci ; 20(2)2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32118258

RESUMO

Age at mating is one of the most important factors that affect mating success and reproductive fitness in insects. The present study investigated how the age of the two sexes at mating determined mating success, reproductive fitness and longevity in Phauda flammans (Walker) (Lepidoptera: Phaudidae), a serious pest of Ficus spp. trees in South and Southeast Asia. The study may provide basic knowledge for the development of mating disruption programs using sex pheromones to control this pest. The species is monandrous and its adults live for only 4-5 d. We show that delayed mating significantly lowered mating success in both sexes, with males being more severely affected than females. Mating delay also reduced reproductive outputs of both sexes but females were more negatively affected than males. We did not find any effect of delayed mating on longevity of either sex. Our findings suggest that mating disruption with sex pheromones can be an effective method to delay mating in P. flammans, reducing reproductive success and thus limit population growth.


Assuntos
Copulação , Fertilidade , Mariposas/fisiologia , Fatores Etários , Animais , Feminino , Longevidade/fisiologia , Masculino
2.
J Chem Ecol ; 46(2): 115-127, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056064

RESUMO

Whittleia retiella (Newman, 1847) is a threatened salt marsh species of the bagworm moth family Psychidae. For its preservation it is necessary to develop efficient tools to survey its distribution and habitat requirements in order to use appropriate conservation methods. Such tools may be pheromone-based monitoring systems, which have documented efficacy in establishing the occurrence of cryptic insect species in nature. By using gas chromatography combined with electroantennographic detection (GC-EAD), we found two compounds in female W. retiella headspace samples and whole-body extracts that elicited electrophysiological activity in male antennae. Gas chromatograpy coupled with mass spectrometry (GC-MS) operating in electron impact (EI) mode and comparison of the analytical data with those of synthetic reference compounds showed the chemical structures of these putative pheromone components to be (1S)-1-methylpropyl (5Z)-dec-5-enoate and 1-methylethyl (5Z)-dec-5-enoate. Field assays using baits loaded with synthetic compounds revealed that conspecific males were attracted to (1S)-1-methylpropyl (5Z)-dec-5-enoate alone or in combination with 1-methylethyl (5Z)-dec-5-enoate, whereas 1-methylethyl (5Z)-dec-5-enoate neither attracted nor repelled males in the field assays when tested alone. This study shows the potential of using (1S)-1-methylpropyl (5Z)-dec-5-enoate for monitoring W. retiella to gather more detailed information about the geographic distribution and habitat needs of this rare moth.


Assuntos
Mariposas/fisiologia , Atrativos Sexuais/química , Animais , Comportamento Animal/efeitos dos fármacos , Fenômenos Eletrofisiológicos , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Atrativos Sexuais/análise , Atrativos Sexuais/farmacologia , Estereoisomerismo , Áreas Alagadas
3.
Naturwissenschaften ; 107(1): 8, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31925556

RESUMO

The partitioning of ß-diversity is a recurrent practice in biogeographic and ecological studies that can provide key insights for land management, such as identification of biodiversity hot-spots. In this study, we used Baselga's metrics to measure the contribution of spatial turnover (ßsim) and nestedness-resultant dissimilarity (ßnes) to overall ß-diversity (ßsor) within- and between-forest types. We analyzed a presence/absence dataset concerning 593 species of nocturnal Lepidoptera sampled within chestnut, silver fir, beech, and black pine forests of southern Italy. Ordination methods and analysis of similarities were used to assess the relative contribution of ßsim and ßnes to ßsor, and to assess their relationships with variables linked to the experimental design and known to be determinant for insect diversity and abundance. We found that ßsor was mostly due to turnover, around 98.5% in ß-diversity assessment of the whole sample, and around 91% in ß-diversity assessment of individual forests. Using ordination analyses based on ßsim, stands were grouped according to forest type, while ßnes alone was used to ordinate stands coherently with their species richness. Nevertheless, the addition of ßnes to ßsim produced a more ecologically coherent grouping of stands within individual forest types, and ßnes alone was able to recognize patterns determined by human disturbance. In conclusion, we demonstrate that ß-diversity partitioning can help to detect differences in magnitude and role of processes determining the composition of forest moth communities as in different forests the same pattern can be due to opposite processes, providing strong ecological insights into managing forest biodiversity.


Assuntos
Biodiversidade , Florestas , Mariposas/classificação , Mariposas/fisiologia , Distribuição Animal , Animais , Itália , Dinâmica Populacional
4.
Arch Insect Biochem Physiol ; 103(4): e21651, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31943343

RESUMO

DNA methylation refers to the addition of cytosine residues in a CpG context (5'-cytosine-phosphate-guanine-3'). As one of the most common mechanisms of epigenetic modification, it plays a crucial role in regulating gene expression and in a diverse range of biological processes across all multicellular organisms. The relationship between temperature and DNA methylation and how it acts on the adaptability of migratory insects remain unknown. In the present work, a 5,496 bp full-length complementary DNA encoding 1,436 amino acids (named MsDnmt1) was cloned from the devastating migratory pest oriental armyworm, Mythimna separata Walker. The protein shares 36.8-84.4% identity with other insect Dnmt1 isoforms. Spatial and temporal expression analysis revealed that MsDnmt1 was highly expressed in adult stages and head tissue. The changing temperature decreased the expression of MsDnmt1 in both high and low temperature condition. Besides, we found that M. separata exhibited the shortest duration time from the last instar to pupae under 36°C environment when injected with DNA methylation inhibitor. Therefore, our data highlight a potential role for DNA methylation in thermal resistance, which help us to understand the biological role adaptability and colonization of migratory pest in various environments.


Assuntos
DNA (Citosina-5-)-Metiltransferase 1/genética , Proteínas de Insetos/genética , Mariposas/fisiologia , Sequência de Aminoácidos , Animais , Temperatura Corporal , DNA (Citosina-5-)-Metiltransferase 1/química , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/genética , Mariposas/crescimento & desenvolvimento , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Filogenia , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/fisiologia , Alinhamento de Sequência
5.
Arch Insect Biochem Physiol ; 103(4): e21655, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31953886

RESUMO

Some studies have highlighted benefits for Lobesia botrana by adding Botrytis cinerea mycelium to an artificial larval diet and have suggested a mutualistic relationship between the two organisms on grapevine, hypothesizing that fungal sterols were the nutritional factor involved. Because the nutritional quality of an artificial diet should be similar to grapes to allow extrapolation of the results to the field conditions, in the current study L. botrana larval performance was compared when larvae were fed on grapes (berries) or two artificial diets either with or without enrichment with B. cinerea. Based on sterol analysis, the two artificial diets had high cholesterol content, but relative to berries showed comparable and low phytosterol contents, respectively (high- and low-phytosterol, HPh, and LPh). While larval fitness on the HPh diet was similar to berries, the LPh diet led to higher mortality and worse larval performance. The addition of the fungus compensated for the shortage in the LPh diet but did not improve the HPh diet. Supplementing the LPh diet with linoleic acid, which is supplied also from B. cinerea, partially improved larval performance. In a field experiment, females did not show any egg-laying preferences towards naturally botrytized bunches. The positive effect of B. cinerea on the moth's next generation that is reported in the literature could be a consequence of fungus developed inside berry tunnels bored by larvae. Therefore, based on our data and previous reports the existence of a mutualistic relationship between L. botrana and B. cinerea is not well-founded.


Assuntos
Botrytis/fisiologia , Mariposas/microbiologia , Mariposas/fisiologia , Simbiose , Ração Animal/análise , Animais , Dieta , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Oviposição , Vitis
6.
PLoS One ; 15(1): e0228157, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31978155

RESUMO

Insect herbivores have the potential to change both physical and chemical traits of their host plant. Although the impacts of herbivores on their hosts have been widely studied, experiments assessing changes in multiple leaf traits or functions simultaneously are still rare. We experimentally tested whether herbivory by winter moth (Operophtera brumata) caterpillars and mechanical leaf wounding changed leaf mass per area, leaf area, leaf carbon and nitrogen content, and the concentrations of 27 polyphenol compounds on oak (Quercus robur) leaves. To investigate how potential changes in the studied traits affect leaf functioning, we related the traits to the rates of leaf photosynthesis and respiration. Overall, we did not detect any clear effects of herbivory or mechanical leaf damage on the chemical or physical leaf traits, despite clear effect of herbivory on photosynthesis. Rather, the trait variation was primarily driven by variation between individual trees. Only leaf nitrogen content and a subset of the studied polyphenol compounds correlated with photosynthesis and leaf respiration. Our results suggest that in our study system, abiotic conditions related to the growth location, variation between tree individuals, and seasonal trends in plant physiology are more important than herbivory in determining the distribution and composition of leaf chemical and structural traits.


Assuntos
Mariposas/fisiologia , Quercus/química , Animais , Carbono/metabolismo , Herbivoria , Interações Hospedeiro-Parasita , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Fotossíntese , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Brotos de Planta/química , Brotos de Planta/metabolismo , Polifenóis/metabolismo , Análise de Componente Principal , Quercus/metabolismo , Quercus/parasitologia , Estações do Ano , Estresse Mecânico
7.
PLoS Comput Biol ; 16(1): e1007452, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31917816

RESUMO

We develop a method to learn a bio-inspired motion control policy using data collected from hawkmoths navigating in a virtual forest. A Markov Decision Process (MDP) framework is introduced to model the dynamics of moths and sparse logistic regression is used to learn control policy parameters from the data. The results show that moths do not favor detailed obstacle location information in navigation, but rely heavily on optical flow. Using the policy learned from the moth data as a starting point, we propose an actor-critic learning algorithm to refine policy parameters and obtain a policy that can be used by an autonomous aerial vehicle operating in a cluttered environment. Compared with the moths' policy, the policy we obtain integrates both obstacle location and optical flow. We compare the performance of these two policies in terms of their ability to navigate in artificial forest areas. While the optimized policy can adjust its parameters to outperform the moth's policy in each different terrain, the moth's policy exhibits a high level of robustness across terrains.


Assuntos
Simulação por Computador , Modelos Biológicos , Navegação Espacial/fisiologia , Algoritmos , Animais , Biologia Computacional , Tomada de Decisões , Processamento de Imagem Assistida por Computador , Aprendizado de Máquina , Cadeias de Markov , Mariposas/fisiologia
8.
J Insect Sci ; 20(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31899494

RESUMO

Mamestra brassicae L. is an important, regionally migratory pest of vegetable crops in Europe and Asia. Its migratory activity contributes significantly to population outbreaks, causing severe crop yield losses. Because an in-depth understanding of flight performance is key to revealing migratory patterns, here we used a computer-linked flight mill and stroboscope to study the flight ability and wingbeat frequency (WBF) of M. brassicae in relation to sex, age, temperature, and relative humidity (RH). The results showed that age significantly affected the flight ability and WBF of M. brassicae, and 3-d-old individuals performed the strongest performance (total flight distance: 45.6 ± 2.5 km; total flight duration: 9.3 ± 0.3 h; WBF: 44.0 ± 0.5 Hz at 24°C and 75% RH). The age for optimal flight was considered to be 2-3 d old. Temperature and RH also significantly affected flight ability and WBF; flight was optimal from 23°C to 25°C and 64-75% RH. Because M. brassicae thus has great potential to undertake long-distance migration, better knowledge of its flight behavior and migration will help establish a pest forecasting and early-warning system.


Assuntos
Voo Animal , Mariposas/fisiologia , Asas de Animais/fisiologia , Fatores Etários , Animais , Feminino , Umidade , Masculino , Fatores Sexuais , Temperatura
9.
Bull Entomol Res ; 110(1): 96-105, 2020 Feb.
Artigo em Italiano | MEDLINE | ID: mdl-31190656

RESUMO

Diamides have been used worldwide to manage the diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Plutellidae), however some strains showed resistance to these molecules. Also, pheromone traps could be used to manage this pest, hence reducing the use of insecticides in the field. Resistant DBM strains may have biological disadvantages in comparison to susceptible strains in areas without sprays, including reduction in fitness or behavioral changes. Therefore, the aim of this study was to investigate whether DBM strains resistant to chlorantraniliprole showed adaptive costs that could alter male attraction to the sex pheromone, in comparison to susceptible strains in the laboratory and semi-field conditions. First, the LC1, LC10, LC25, and LC50 of DBM to chlorantraniliprole were established, which were 0.003, 0.005, 0.007, and 0.011 mg a.i. liter-1, and 5.88, 24.80, 57.22, and 144.87 mg a.i. liter-1 for the susceptible and resistant strains, respectively. Development and reproduction of DBM strains subjected to those concentrations were compared. Later, male response to the sex pheromone was investigated in a Y-tube in the laboratory and in a greenhouse to pheromone traps. Resistant DBM strain showed an adaptive cost in comparison to the susceptible strain that can result in a delay in population growth in the field when selection pressure is absent. Conversely, resistant males have no olfactory response alteration in comparison to susceptible males, consistently at 3 (P = 0.6848) and 7 days (P = 0.9140) after release, suggesting that pheromone traps continue to be a viable alternative to manage DBM in an IPM system.


Assuntos
Adaptação Biológica , Inseticidas , Mariposas/fisiologia , Comportamento Sexual Animal/fisiologia , ortoaminobenzoatos , Animais , Resistência a Inseticidas/fisiologia , Masculino , Atrativos Sexuais , Olfato
10.
Insect Biochem Mol Biol ; 116: 103243, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31541694

RESUMO

Sterile insect technology (SIT) is an environmentally friendly method for pest control. As part of our efforts to develop a strategy that results in engineered male-sterile strains with minimum effects on viability and mating competition, we used CRISPR/Cas9 technology to disrupt Ser2, which encodes a seminal fluid protein, in the model lepidopteran insect, Bombyx mori, and an important agricultural pest, Plutella xylostella. Disruption of Ser2 resulted in dominant heritable male sterility. Wild-type females mated with Ser2-deficient males laid eggs normally, but the eggs did not hatch. We detected no differences in other reproductive behaviors in the mutant males. These results support the conclusion that Ser2 gene is necessary for male reproductive success in diverse lepidopterans. Targeting Ser2 gene has the potential to form the basis for a new strategy for pest control.


Assuntos
Proteínas de Insetos/genética , Mariposas/fisiologia , Serina Proteases/genética , Animais , Bombyx/genética , Bombyx/fisiologia , Sistemas CRISPR-Cas , Infertilidade Masculina/genética , Proteínas de Insetos/metabolismo , Masculino , Mariposas/genética , Mutação , Reprodução/genética , Serina Proteases/metabolismo
11.
J Agric Food Chem ; 68(1): 88-96, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31826619

RESUMO

Solanum rostratum is a worldwide malignant invasive weed, causing serious harm to the ecological environment and biodiversity. Strong chemical defense against herbivorous insects is supposed to be one of the successful invasive mechanisms of this exotic plant. However, the real defense components and their action mechanisms and distributions are still unknown. To address these problems, we bioassay-guided isolated compounds from the aerial part of S. rostratum and determined their structures using high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance, and electronic circular dichroism calculation. One new and seven known compounds were identified, and all of the isolates exhibited different levels of antifeedant activities, especially compounds 1 and 4. Consistently, compounds 1 and 4 displayed potent inhibitory effects on antifeedant-related enzymes (AchE and CarE). The action mechanisms of active compounds 1 and 4 were revealed by molecular docking and molecular dynamic simulation studies. Furthermore, the distributions of the active compounds in leaves, stems, and flowers were also analyzed by liquid chromatography-mass spectrometry.


Assuntos
Comportamento Alimentar/efeitos dos fármacos , Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Daninhas/química , Solanum/química , Animais , Flores/química , Flores/metabolismo , Inseticidas/química , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Mariposas/fisiologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Plantas Daninhas/metabolismo , Metabolismo Secundário , Solanum/metabolismo , Espectrometria de Massas por Ionização por Electrospray
12.
J Chem Ecol ; 46(2): 217-231, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31879865

RESUMO

Despite active research, antiherbivore activity of specific plant phenolics remains largely unresolved. We constructed silver birch (Betula pendula) lines with modified phenolic metabolism to study the effects of foliar flavonoids and condensed tannins on consumption and growth of larvae of a generalist herbivore, the autumnal moth (Epirrita autumnata). We conducted a feeding experiment using birch lines in which expression of dihydroflavonol reductase (DFR), anthocyanidin synthase (ANS) or anthocyanidin reductase (ANR) had been decreased by RNA interference. Modification-specific effects on plant phenolics, nutrients and phenotype, and on larval consumption and growth were analyzed using uni- and multivariate methods. Inhibiting DFR expression increased the concentration of flavonoids at the expense of condensed tannins, and silencing DFR and ANR decreased leaf and plant size. E. autumnata larvae consumed on average 82% less of DFRi plants than of unmodified controls, suggesting that flavonoids or glandular trichomes deter larval feeding. However, larval growth efficiency was highest on low-tannin DFRi plants, indicating that condensed tannins (or their monomers) are physiologically more harmful than non-tannin flavonoids for E. autumnata larvae. Our results show that genetic manipulation of the flavonoid pathway in plants can effectively be used to produce altered phenolic profiles required for elucidating the roles of low-molecular weight phenolics and condensed tannins in plant-herbivore relationships, and suggest that phenolic secondary metabolites participate in regulation of plant growth.


Assuntos
Betula/química , Flavonoides/metabolismo , Mariposas/fisiologia , Plantas Geneticamente Modificadas/química , Taninos/metabolismo , Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Animais , Betula/enzimologia , Betula/parasitologia , Flavonoides/farmacologia , Herbivoria/efeitos dos fármacos , Interações Hospedeiro-Parasita , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Oxigenases/antagonistas & inibidores , Oxigenases/genética , Oxigenases/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/parasitologia , Interferência de RNA , Taninos/farmacologia
13.
J Chem Ecol ; 46(1): 10-20, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31845137

RESUMO

Female moths release sex pheromone to attract mates. In most species, sex pheromone is produced in, and released from, a specific gland. In a previous study, we used empirical data and compartmental modeling to account for the major pheromone gland processes of female Chloridea virescens: synthesis, storage, catabolism and release; we found that females released little (20-30%) of their pheromone, with most catabolized. The recent publication of a new pheromone collection method led us to reinvestigate pheromone release and catabolism in C. virescens on the basis that our original study might have underestimated release rate (thereby overestimating catabolism) due to methodology and females not calling (releasing) continuously. Further we wished to compare pheromone storage/catabolism between calling and non-calling females. First, we observed calling intermittency of females. Then, using decapitated females, we used the new collection method, along with compartmental modeling, gland sampling and stable isotope labeling, to determine differences in pheromone release, catabolism and storage between (forced) simulated calling and non-calling females. We found, (i) intact 1 d females call intermittently; (ii) pheromone is released at a higher rate than previously determined, with simulations estimating that continuously calling females release ca. 70% of their pheromone (only 30% catabolized); (iii) extension (calling)/retraction of the ovipositor is a highly effective "on/off' mechanism for release; (iv) both calling and non-calling females store most pheromone on or near the gland surface, but calling females catabolize less pheromone; (v) females are capable of producing and releasing pheromone very rapidly. Thus, not only is the moth pheromone gland efficient, in terms of the proportion of pheromone released Vs. catabolized, but it is highly effective at shutting on/off a high flux of pheromone for release.


Assuntos
Mariposas/fisiologia , Atrativos Sexuais/metabolismo , Comportamento Sexual Animal , Aldeídos/análise , Aldeídos/farmacologia , Animais , Isótopos de Carbono/química , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Glucose/química , Glucose/metabolismo , Marcação por Isótopo , Masculino , Glândulas Odoríferas/metabolismo , Atrativos Sexuais/análise , Atrativos Sexuais/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos
14.
J Chem Ecol ; 46(1): 21-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31853815

RESUMO

Female Helicoverpa armigera emit a pheromone, comprised of a 98:2 ratio of (Z)-11-hexadecenal to (Z)-9-hexadecenal, to attract males. It has been proposed that "immature" female H. armigera modulate attraction of males by emitting an antagonist, (Z)-11-hexadecenol, along with pheromone during the first two nights of calling. However, it is unclear why females would call and simultaneously release pheromone and an antagonist. We conducted observations of female calling during the first five nights after adult emergence to determine periodicity. We also measured the relative abundance of (Z)-11-hexadecenol to the major component, (Z)-11-hexadecenal, on the surface of the gland of calling females and compared it to the ratio of these two compounds inside the gland over the first three nights after adult emergence to determine how much antagonist may be released. We found that young females (< 1-d-old) are unlikely to call and, based on the relative proportion of (Z)-11-hexadecenol on the gland surface, even if they did call would be unlikely to release sufficient (Z)-11-hexadecenol to diminish male attraction.


Assuntos
Fertilidade/fisiologia , Mariposas/fisiologia , Atrativos Sexuais/química , Aldeídos/análise , Aldeídos/isolamento & purificação , Aldeídos/farmacologia , Animais , Cromatografia Gasosa , Feminino , Masculino , Atrativos Sexuais/análise , Atrativos Sexuais/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos , Microextração em Fase Sólida , Estereoisomerismo
15.
Insect Sci ; 27(1): 49-57, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29999564

RESUMO

In agro-ecosystems, plants are important mediators of interactions between their associated herbivorous insects and microbes, and any change in plants induced by one species may lead to cascading effects on interactions with other species. Often, such effects are regulated by phytohormones such as jasmonic acid (JA) and salicylic acid (SA). Here, we investigated the tripartite interactions among rice plants, three insect herbivores (Chilo suppressalis, Cnaphalocrocis medinalis or Nilaparvata lugens), and the causal agent of rice blast disease, the fungus Magnaporthe oryzae. We found that pre-infestation of rice by C. suppressalis or N. lugens but not by C. medinalis conferred resistance to M. oryzae. For C. suppressalis and N. lugens, insect infestation without fungal inoculation induced the accumulation of both JA and SA in rice leaves. In contrast, infestation by C. medinalis increased JA levels but reduced SA levels. The exogenous application of SA but not of JA conferred resistance against M. oryzae. These results suggest that pre-infestation by C. suppressalis or N. lugens conferred resistance against M. oryzae by increasing SA accumulation. These findings enhance our understanding of the interactions among rice plant, insects and pathogens, and provide valuable information for developing an ecologically sound strategy for controlling rice blast.


Assuntos
Hemípteros/fisiologia , Herbivoria , Magnaporthe/fisiologia , Mariposas/fisiologia , Oryza/microbiologia , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Animais , Resistência à Doença/fisiologia
16.
J Chem Ecol ; 45(11-12): 972-981, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31713110

RESUMO

Microplitis croceipes is a solitary parasitoid that specializes on noctuid larvae of Helicoverpa zea and Heliothis virescens. Both the parasitoid and its hosts are naturally distributed across a large part of North America. When parasitoids deposit their eggs into hosts, venom and polydnaviruses (PDVs) are also injected into the caterpillars, which can suppress host immune responses, thus allowing parasitoid larvae to develop. In addition, PDVs can regulate host oral cues, such as glucose oxidase (GOX). The purpose of this study was to determine if parasitized caterpillars differentially induce plant defenses compared to non-parasitized caterpillars using two different caterpillar host/plant systems. Heliothis virescens caterpillars parasitized by M. croceipes had significantly lower salivary GOX activity than non-parasitized caterpillars, resulting in lower levels of tomato defense responses, which benefited parasitoid performance by increasing the growth rate of parasitized caterpillars. In tobacco plants, parasitized Helicoverpa zea caterpillars had lower GOX activity but induced higher plant defense responses. The higher tobacco defense responses negatively affected parasitoid performance by reducing the growth rate of parasitized caterpillars, causing longer developmental periods, and reduced cocoon mass and survival of parasitoids. These studies demonstrate a species-specific effect in different plant-insect systems. Based on these results, plant perception of insect herbivores can be affected by parasitoids and lead to positive or negative consequences to higher trophic levels depending upon the particular host-plant system.


Assuntos
Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Tabaco/parasitologia , Vespas/fisiologia , Animais , Feminino , Glucose Desidrogenase/metabolismo , Glucose Oxidase/metabolismo , Interações Hospedeiro-Parasita , Larva/metabolismo , Lycopersicon esculentum/metabolismo , Oviposição/fisiologia , Parasitos , Doenças das Plantas/parasitologia , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Especificidade da Espécie , Tabaco/metabolismo
17.
J Chem Ecol ; 45(11-12): 946-958, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31755018

RESUMO

There are contrasting hypotheses regarding the role of plant volatiles in host plant location. We used the grape berry moth (GBM; Paralobesia viteana)-grape plant (Vitis spp.) complex as a model for studying the proximate mechanisms of long distance olfactory-mediated, host-plant location and selection by a specialist phytophagous insect. We used flight tunnel assays to observe GBM female in-flight responses to host (V. riparia) and non-host (apple, Malus domestica; and gray dogwood, Cornus racimosa,) odor sources in the form of plant shoots, extracts of shoots, and synthetic blends. Gas chromatography-electroantennographic detection and gas chromatography/mass spectrometry analyses were used to identify antennal-active volatile compounds. All antennal-active compounds found in grape shoots were also present in dogwood and apple shoots. Female GBM flew upwind to host and non-host extracts and synthetic blends at similar levels, suggesting discrimination is not occurring at long distance from the plant. Further, females did not land on sources releasing plant extracts and synthetic blends, suggesting not all landing cues were present. Additionally, mated and unmated moths displayed similar levels of upwind flight responses to all odor sources, supporting the idea that plant volatiles are not functioning solely as ovipositional cues. The results of this study support a hypothesis that GBM females are using volatile blends to locate a favorable habitat rather than a specific host plant, and that discrimination is occurring within the habitat, or even post-landing.


Assuntos
Mariposas/fisiologia , Oviposição/efeitos dos fármacos , Extratos Vegetais/química , Vitis/química , Compostos Orgânicos Voláteis/química , Animais , Comportamento Animal , Cornus/química , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Controle de Insetos/métodos , Malus/química , Odorantes/análise , Brotos de Planta/química , Olfato , Vitis/parasitologia , Compostos Orgânicos Voláteis/metabolismo
18.
Nat Commun ; 10(1): 4554, 2019 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-31591404

RESUMO

Explaining colour variation among animals at broad geographic scales remains challenging. Here we demonstrate how deep learning-a form of artificial intelligence-can reveal subtle but robust patterns of colour feature variation along an ecological gradient, as well as help identify the underlying mechanisms generating this biogeographic pattern. Using over 20,000 images with precise GPS locality information belonging to nearly 2,000 moth species from Taiwan, our deep learning model generates a 2048-dimension feature vector that accurately predicts each species' mean elevation based on colour and shape features. Using this multidimensional feature vector, we find that within-assemblage image feature variation is smaller in high elevation assemblages. Structural equation modeling suggests that this reduced image feature diversity is likely the result of colder environments selecting for darker colouration, which limits the colour diversity of assemblages at high elevations. Ultimately, with the help of deep learning, we will be able to explore the endless forms of natural morphological variation at unpreceded depths.


Assuntos
Inteligência Artificial , Biodiversidade , Cor , Variação Genética , Insetos/genética , Pigmentação da Pele/genética , Altitude , Animais , Clima , Aprendizado Profundo , Insetos/fisiologia , Mariposas/classificação , Mariposas/genética , Mariposas/fisiologia , Filogenia , Especificidade da Espécie , Temperatura
19.
BMC Genomics ; 20(1): 751, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31623553

RESUMO

BACKGROUND: Massive techniques have been evaluated for developing different pest control methods to minimize fertilizer and pesticide inputs. As "push-pull" strategy utilizes generally non-toxic chemicals to manipulate behaviors of insects, such strategy is considered to be environmentally friendly. "Push-pull" strategy has been extraordinarily effective in controlling stem borers, and the identification of new "pushing" or "pull" components against stem borers could be significantly helpful. RESULTS: In this study, the results of field trapping assay and behavioral assay showed the larvae of C.auricilius, one kind of stem borers, could be deterred by rice plant under tilling stage, its main host crop. The profiles of volatiles were compared between rice plants under two different developmental stages, and α-pinene was identified as a key differential component. The repelling activity of α-pinene against C.auricilius was confirmed by Y-tube olfactometer. For illuminating the olfactory recognition mechanism, transcriptome analysis was carried out, and 13 chemosensory proteins (CSPs) were identified in larvae and 19 CSPs were identified in adult of C.auriciliu, which was reported for the first time in this insect. Among these identified CSPs, 4 CSPs were significantly regulated by α-pinene treatment, and CSP8 showed good binding affinity with α-pinene in vitro. CONCLUSIONS: Overall, C.auricilius could be repelled by rice plant at tilling stage, and our results highlighted α-pinene as a key component in inducing repelling activity at this specific stage and confirmed the roles of some candidate chemosensory elements in this chemo-sensing process. The results in this study could provide valuable information for chemosensory mechanism of C.auricilius and for identification of "push" agent against rice stem borers.


Assuntos
Repelentes de Insetos/metabolismo , Mariposas/fisiologia , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Compostos Orgânicos Voláteis/metabolismo , Animais , Quimiotaxia/genética , Quimiotaxia/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/genética , Larva/fisiologia , Mariposas/classificação , Mariposas/genética , Oryza/química , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/parasitologia , Doenças das Plantas/parasitologia , Proteínas de Plantas/genética , Ligação Proteica
20.
BMC Plant Biol ; 19(1): 431, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31623579

RESUMO

BACKGROUND: Corn borers constitute an important pest of maize around the world; in particular Sesamia nonagrioides Lefèbvre, named Mediterranean corn borer (MCB), causes important losses in Southern Europe. Methods of selection can be combined with transgenic approaches to increase the efficiency and durability of the resistance to corn borers. Previous studies of the genetic factors involved in resistance to MCB have been carried out using bi-parental populations that have low resolution or using association inbred panels that have a low power to detect rare alleles. We developed a Multi-parent Advanced Generation InterCrosses (MAGIC) population to map with high resolution the genetic determinants of resistance to MCB. RESULTS: We detected multiple single nucleotide polymorphisms (SNPs) of low effect associated with resistance to stalk tunneling by MCB. We dissected a wide region related to stalk tunneling in multiple studies into three smaller regions (at ~ 150, ~ 155, and ~ 165 Mb in chromosome 6) that closely overlap with regions associated with cell wall composition. We also detected regions associated with kernel resistance and agronomic traits, although the co-localization of significant regions between traits was very low. This indicates that it is possible the concurrent improvement of resistance and agronomic traits. CONCLUSIONS: We developed a mapping population which allowed a finer dissection of the genetics of maize resistance to corn borers and a solid nomination of candidate genes based on functional information. The population, given its large variability, was also adequate to map multiple traits and study the relationship between them.


Assuntos
Resistência à Doença/genética , Mariposas/fisiologia , Doenças das Plantas/imunologia , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Zea mays/genética , Alelos , Animais , Mapeamento Cromossômico , Estudo de Associação Genômica Ampla , Genótipo , Fenótipo , Doenças das Plantas/parasitologia , Zea mays/imunologia , Zea mays/parasitologia
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