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1.
J Insect Sci ; 22(5)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36256385

RESUMO

Navel orangeworm, Amyelois transitella (Walker), is a key pest of walnuts, pistachio, and almonds in California. Pheromone mating disruption using timed aerosol dispensers is an increasingly common management technique. Dispenser efficiency may be increased by timing releases with the active mating period of navel orangeworm. Past work found that the peak time of sexual activity for navel orangeworm females is 2 h before sunrise when temperatures are above 18°C. Inference of male responsiveness from data collected in that study was limited by the necessity of using laboratory-reared females as a source of sex pheromone emission to attract males and the inherent limitations of human observers for nocturnal events. Here we used camera traps baited with artificial pheromone to observe male navel orangeworm mating response in the field over two field seasons. Male response to synthetic pheromone exhibited diel patterns broadly similar to females, i.e., they were active for a brief period of 2-3 h before dawn under summer conditions and began responding to pheromone earlier and over a longer period of time during spring and fall. But contrary to the previous findings with females, some males were captured at all hours of the day and night, and there was no evidence of short-term change of pheromone responsiveness in response to temperature. Environmental effects on the response of navel orangeworm males to an artificial pheromone source differ in important ways from the environmental effects on female release of sex pheromone.


Assuntos
Mariposas , Prunus dulcis , Atrativos Sexuais , Humanos , Masculino , Feminino , Animais , Atrativos Sexuais/farmacologia , Mariposas/fisiologia , Feromônios/farmacologia , Aerossóis
2.
Molecules ; 27(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36080239

RESUMO

Natural defensive substances synthesized by plants that could replace synthetic pesticides in the protection of plants against insect invasions are constantly being sought. The study assessed changes in the qualitative and quantitative composition of secondary metabolites in horse chestnut leaves collected in different locations and differing in the sensitivity of the plant to the invasion by the horse-chestnut leaf miner. An attempt was made to identify compounds that are most responsible for the increased plant resistance to this threat. Additionally, changes in the anatomy of chestnut leaves affected by the pest were presented. It was noticed that the trees differed in the composition of secondary metabolites already in the initial growing season, which should be related to the influence of habitat conditions. The analysis of the profile of the compounds in non-infested and infested horse chestnut leaves revealed a clear response of the plant to the stress factor, i.e., the foraging of the horse-chestnut leaf miner. Catechins seem to be compounds involved in plant resistance. The leaf anatomy showed enhanced accumulation of phenolic compounds at the pest foraging sites. Hypertrophy and thickened and cracked cell walls of the spongy parenchyma were visible in the vicinity of the mines.


Assuntos
Aesculus , Fagaceae , Mariposas , Animais , Ecossistema , Mariposas/fisiologia , Folhas de Planta , Árvores
3.
J Exp Biol ; 225(18)2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36111562

RESUMO

Tiger moth species vary greatly in the number of clicks they produce and the resultant duty cycle. Signals with higher duty cycles are expected to more effectively interfere with bat sonar. However, little is known about the minimum duty cycle of tiger moth signals for sonar jamming. Is there a threshold that allows us to classify moths as acoustically aposematic versus sonar jammers based on their duty cycles? We performed playback experiments with three wild-caught adult male bats, Eptesicus fuscus. Bat attacks on tethered moths were challenged using acoustic signals of Bertholdia trigona with modified duty cycles ranging from 0 to 46%. We did not find evidence for a duty cycle threshold; rather, the ability to jam the bat's sonar was a continuous function of duty cycle consistent with a steady increase in the number of clicks arriving during a critical signal processing time window just prior to the arrival of an echo. The proportion of successful captures significantly decreased as the moth duty cycle increased. Our findings suggest that moths cannot be unambiguously classified as acoustically aposematic or sonar jammers based solely on duty cycle. Bats appear to compensate for sonar jamming by lengthening the duration of their terminal buzz and they are more successful in capturing moths when they do so. In contrast to previous findings for bats performing difficult spatial tasks, the number of sonar sound groups decreased in response to high duty cycles and did not affect capture success.


Assuntos
Quirópteros , Ecolocação , Mariposas , Animais , Quirópteros/fisiologia , Ecolocação/fisiologia , Masculino , Mariposas/fisiologia , Comportamento Predatório/fisiologia , Som , Vocalização Animal/fisiologia
4.
J Chem Ecol ; 48(9-10): 683-689, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36138313

RESUMO

The pink grass worm, Tmetolophota atristriga (Walker), is an endemic New Zealand noctuid moth species that is abundant throughout the North and South Islands. The larvae are minor defoliators of agricultural pasture. We investigated the sex pheromone of this species. Analysis of extract of the female sex pheromone gland identified six compounds: two monounsaturated compounds, (Z)-11-hexadecenal (Z11-16:Ald) and (Z)-11-hexadecenyl acetate (Z11-16:Ac), three saturated compounds, hexadecanal (16:Ald), hexadecyl acetate (16:Ac) and octadecan-1-ol (18:OH), and a triene hydrocarbon, (3Z,6Z,9Z)-tricosatriene (Z3Z6Z9-23:Hy). Several field-trapping experiments testing combinations of the six compounds were conducted. Results suggested that males of two different populations of T. atristriga responded differently to different blends of the compounds. Males of one population responded equally to a two-component blend as to other blends, including the one with all six compounds. By contrast, males of the second population responded only to the six-component blend or a ternary blend of Z11-16:Ald, Z11-16:Ac and Z3Z6Z9-23:Hy. In experiments testing different doses of Z11-16:Ald and Z11-16:Ac in a binary or a six-component blend, a 1 mg dose of the binary blend gave the greatest male catch for both populations. This is the second sex pheromone identification of a New Zealand species of Noctuidae and is the first reported occurrence of Z3Z6Z9-23:Hy as a sex pheromone component of any noctuid species.


Assuntos
Mariposas , Atrativos Sexuais , Masculino , Feminino , Animais , Atrativos Sexuais/análise , Poaceae , Mariposas/fisiologia , Nova Zelândia
5.
J Chem Ecol ; 48(9-10): 718-729, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35972714

RESUMO

Insect herbivores have evolved a broad spectrum of adaptations in response to the diversity of chemical defences employed by plants. Here we focus on two species of New Guinean Asota and determine how these specialist moths deal with the leaf alkaloids of their fig (Ficus) hosts. As each focal Asota species is restricted to one of three chemically distinct species of Ficus, we also test whether these specialized interactions lead to similar alkaloid profiles in both Asota species. We reared Asota caterpillars on their respective Ficus hosts in natural conditions and analyzed the alkaloid profiles of leaf, frass, caterpillar, and adult moth samples using UHPLC-MS/MS analyses. We identified 43 alkaloids in our samples. Leaf alkaloids showed various fates. Some were excreted in frass or found in caterpillars and adult moths. We also found two apparently novel indole alkaloids-likely synthesized de novo by the moths or their microbiota-in both caterpillar and adult tissue but not in leaves or frass. Overall, alkaloids unique or largely restricted to insect tissue were shared across moth species despite feeding on different hosts. This indicates that a limited number of plant compounds have a direct ecological function that is conserved among the studied species. Our results provide evidence for the importance of phytochemistry and metabolic strategies in the formation of plant-insect interactions and food webs in general. Furthermore, we provide a new potential example of insects acquiring chemicals for their benefit in an ecologically relevant insect genus.


Assuntos
Alcaloides , Ficus , Mariposas , Animais , Nova Guiné , Espectrometria de Massas em Tandem , Larva/fisiologia , Mariposas/fisiologia , Herbivoria , Insetos , Plantas , Metaboloma
6.
Sci Rep ; 12(1): 14702, 2022 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-36038763

RESUMO

The soybean looper, Chrysodeixis includens, is a primary soybean pest that reduces crop productivity. This work examined control of C. includens populations with methanolic extract of Serjania erecta, a native Cerrado plant, while minimizing risks to pollinators, natural enemies and the environment. Serjania erecta specimens were collected, identified, and subjected to methanol extraction. Bioassays were performed using newly hatched and second-instar caterpillars and different extract concentrations on the diet surface to obtain IC50 values. Two replicates, containing 10 caterpillars, were established in triplicate. The IC50 values were 4.15 and 6.24 mg of extract mL-1 for first-instar and second-instar caterpillars, respectively. These growth inhibition results informed the extract concentrations assessed in subsequent development inhibition assays, in which the pupal weight was higher under the control than under the treatments. Extract treatments increased the duration of the larval, pupal and total development. The potential of different concentrations of S. erecta extract to inhibit the enzymes carboxylesterases was also evaluated. Carboxylesterases activity decreased by 41.96 and 43.43% at 7.8 and 15.6 µg mL-1 extract, respectively. At 31.3 µg mL-1 extract, enzymatic activity was not detected. Overall, S. erecta leaf methanolic extract showed inhibitory potential against carboxylesterases.


Assuntos
Mariposas , Sapindaceae , Animais , Hidrolases de Éster Carboxílico/farmacologia , Larva/fisiologia , Mariposas/fisiologia , Extratos Vegetais/farmacologia , Pupa , Soja
7.
J Econ Entomol ; 115(5): 1499-1504, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-35988020

RESUMO

Electrophysiological methods were used to test the visual sensitivity of European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae) to wavelengths ranging from 300 to 700 nm. For male and females tested, a main, peak response occurred in the 460-540 nm range (blue-green wavelengths) with females having a generally lower response to wavelengths in that range. A second smaller peak was observed for both sexes at the 340-420 nm range. A general linear model indicated that males, virgin females, and mated females did not react differently to changes in wavelength. No moths showed any obvious sensitivity to wavelengths between 580 and 700 nm. Based on our retinal recording data we suggest that UV light traps (≤480 nm) could be utilized alongside pheromone traps when monitoring L. botrana in high risk areas.


Assuntos
Mariposas , Animais , Feminino , Masculino , Mariposas/fisiologia , Feromônios , Reprodução
8.
Science ; 377(6607): 764-768, 2022 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-35951704

RESUMO

Each year, trillions of insects make long-range seasonal migrations. These movements are relatively well understood at a population level, but how individual insects achieve them remains elusive. Behavioral responses to conditions en route are little studied, primarily owing to the challenges of tracking individual insects. Using a light aircraft and individual radio tracking, we show that nocturnally migrating death's-head hawkmoths maintain control of their flight trajectories over long distances. The moths did not just fly with favorable tailwinds; during a given night, they also adjusted for head and crosswinds to precisely hold course. This behavior indicates that the moths use a sophisticated internal compass to maintain seasonally beneficial migratory trajectories independent of wind conditions, illuminating how insects traverse long distances to take advantage of seasonal resources.


Assuntos
Migração Animal , Voo Animal , Mariposas , Animais , Voo Animal/fisiologia , Insetos , Mariposas/fisiologia , Vento
9.
Pest Manag Sci ; 78(11): 4446-4457, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35775140

RESUMO

BACKGROUND: Climate warming presents physiological challenges to insects, manifesting as loss of key life-history fitness traits and survival. For interacting host-parasitoid species, physiological responses to heat stress may vary, thereby potentially uncoupling trophic ecological relationships. Here, we assessed heat tolerance traits and sensitivity to prevailing and future maximum temperatures for the cereal stemborer pests, Chilo partellus, Busseola fusca and Sesamia calamistis and their endo-parasitoids, Cotesia sesamiae and Cotesia flavipes. We further used the machine learning algorithm, Maximum Entropy (MaxEnt), to model current and potential distribution of these species. RESULTS: The mean critical thermal maxima (CTmax ) ranged from 39.5 ± 0.9°C to 44.6 ± 0.6°C and from 46.8 ± 0.7°C to 48.5 ± 0.9°C for parasitoids and stemborers, with C. sesamiae and Ch. partellus exhibiting the lowest and highest CTmax respectively. From the current climate to the 2050s scenario, parasitoids recorded a significant reduction in warming tolerance compared with their hosts. Habitat suitability for all stemborer-parasitoid species was spatially heterogeneous under current and future climatic scenarios. Cotesia sesamiae C. flavipes and B. fusca exhibited significant habitat loss, whereas Ch. partellus and S. calamistis showed a significant habitat gain under future 2050s predictions. Model metrics based on mean area under the curve ranged from 0.72 to 0.84 for all species, indicating a good predictive performance of the models. CONCLUSION: These results suggest C. sesamiae and C. flavipes may face survival constraints or extirpation compared with their pest hosts when environmental temperature reaches their upper thermal limits earlier, likely reducing pest regulation through density-mediated effects. The results demonstrate potential destabilization of stemborer-parasitoid trophic systems potentially compromising biocontrol efficacy under climate warming. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Mariposas , Vespas , Animais , Mudança Climática , Grão Comestível , Mariposas/fisiologia , Controle de Pragas , Vespas/fisiologia
10.
J Chem Ecol ; 48(7-8): 618-627, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35831729

RESUMO

The cotton bollworm, Helicoverpa armigera, is one of the most destructive agricultural pests in the world, infesting cotton, maize, soybean, and many other crops. In recent years, H. armigera has been observed damaging walnuts, Juglans regia, in Xinjiang China. Here we examine the chemical perception by H. armigera of the marginal host J. regia. In Y-tube olfactometer tests, we found H. armigera females and males both showed significant behavioral responses to odors from walnut branches. Furthermore, nine electrophysiologically active volatiles (α-pinene, ß-pinene, myrcene, limonene, eucalyptol, ocimene, ß-caryophyllene, (E)-ß-farnesene, and germacrene D) were identified from walnuts with gas chromatography coupled with electroantennography (GC-EAD) and gas chromatography-mass spectrometry (GC-MS). Among these volatiles, ß-pinene and eucalyptol were released in relatively higher amounts. In electroantennogram (EAG) dose-dependent trials, all compounds evoked responses in H. armigera adults when tested at high concentrations, with germacrene D evoking the greatest response. In wind tunnel tests, H. armigera females preferred eight of the electrophysiologically active volatile dilutions compared with clean air, while males showed preference for only five compounds. As such we describe the chemical recognition of H. armigera for walnut, a marginal host. This study contributes to understanding the interaction between polyphagous pests and their host plants.


Assuntos
Juglans , Mariposas , Animais , Produtos Agrícolas , Eucaliptol , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Mariposas/fisiologia , Odorantes/análise , Percepção
11.
Toxins (Basel) ; 14(7)2022 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-35878193

RESUMO

Management of pod borer, Helicoverpa armigera in pigeonpea (Cajanus cajan L.), an important legume crop, has been a pertinent endeavor globally. As with other crops, wild relatives of pigeonpea are bestowed with various resistance traits that include the ability to deter the H. armigera. Understanding the molecular basis of pod borer resistance could provide useful leads for the management of this notorious herbivore. Earlier studies by our group in deciphering the resistance response to herbivory through multiomics approaches in the pigeonpea wild relative, Cajanus platycarpus, divulged the involvement of the flavonoid biosynthesis pathway, speculating an active chemical response of the wild relative to herbivory. The present study is a deeper understanding of the chemical basis of pod borer (H. armigera) resistance in, C. platycarpus, with focus on the flavonoid biosynthesis pathway. To substantiate, quantification of transcripts in H. armigera-challenged C. platycarpus (8 h, 24 h, 48 h, 96 h) showed dynamic upregulation (up to 11-fold) of pivotal pathway genes such as chalcone synthase, dihydroflavonol-4-reductase, flavonoid-3'5'-hydroxylase, flavonol synthase, leucoanthocyanidin reductase, and anthocyanidin synthase. Targeted LC-MS analyses demonstrated a concomitant increase (up to 4-fold) in naringenin, kaempferol, quercetin, delphinidin, cyanidin, epigallocatechin, and epicatechin-3-gallate. Interestingly, H. armigera diet overlaid with the over-produced flavonoids (100 ppm) showed deleterious effects on growth leading to a prolonged larval period demonstrating noteworthy coherence between over-accumulation of pathway transcripts/metabolites. The study depicts novel evidence for the directed metabolic reprogramming of the flavonoid biosynthesis pathway in the wild relative to pod borer; plant metabolic potential is worth exploiting for pest management.


Assuntos
Cajanus , Mariposas , Animais , Cajanus/química , Cajanus/genética , Flavonoides , Herbivoria , Larva , Mariposas/fisiologia
12.
New Phytol ; 235(6): 2378-2392, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35717563

RESUMO

Plants face attackers aboveground and belowground. Insect root herbivores can lead to severe crop losses, yet the underlying transcriptomic responses have rarely been studied. We studied the dynamics of the transcriptomic response of Brussels sprouts (Brassica oleracea var. gemmifera) primary roots to feeding damage by cabbage root fly larvae (Delia radicum), alone or in combination with aboveground herbivory by cabbage aphids (Brevicoryne brassicae) or diamondback moth caterpillars (Plutella xylostella). This was supplemented with analyses of phytohormones and the main classes of secondary metabolites; aromatic, indole and aliphatic glucosinolates. Root herbivory leads to major transcriptomic rearrangement that is modulated by aboveground feeding caterpillars, but not aphids, through priming soon after root feeding starts. The root herbivore downregulates aliphatic glucosinolates. Knocking out aliphatic glucosinolate biosynthesis with CRISPR-Cas9 results in enhanced performance of the specialist root herbivore, indicating that the herbivore downregulates an effective defence. This study advances our understanding of how plants cope with root herbivory and highlights several novel aspects of insect-plant interactions for future research. Further, our findings may help breeders develop a sustainable solution to a devastating root pest.


Assuntos
Brassica , Mariposas , Animais , Brassica/genética , Brassica/metabolismo , Glucosinolatos/metabolismo , Herbivoria/fisiologia , Insetos/metabolismo , Larva/fisiologia , Mariposas/fisiologia , Transcriptoma/genética
13.
Environ Entomol ; 51(4): 643-648, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35762335

RESUMO

To work effectively, the eyes of nocturnal insects have a problem they must overcome. During the night, the light levels are low, so their eyes need to be very sensitive; but they also need a way of adapting to environmental light conditions, and protecting those sensitive organs, if a bright light is encountered. Human eyes have a pupil that changes size to regulate light input to the eye. Moths (Lepidoptera) use a light absorbing pigment that moves position to limit the light within the eye. This pigment migration is difficult to record because it is a dynamic process and will only occur in a live moth. This paper presents the first use of Ocular Coherence Tomography as a method of viewing anatomical detail in a compound eye. This is noninvasive and does not harm the insect. To demonstrate the effectiveness, this article documents the dynamic process of light adaptation within a moth's eye.


Assuntos
Mariposas , Adaptação Ocular , Animais , Humanos , Insetos , Mariposas/fisiologia , Tomografia de Coerência Óptica , Visão Ocular
14.
Ecotoxicol Environ Saf ; 241: 113763, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35696962

RESUMO

The immunotoxicity induced by heavy metals on herbivorous insects reflect the alterations of the susceptibility to entomopathogenic agents in herbivorous insects exposed to heavy metal. In the present study, the susceptibility of gypsy moth larvae to Bacillus thuringiensis under Cd treatment at low and high dosages was investigated, and the gut microbiome-hemolymph metabolome responses that affected larval disease susceptibility caused by Cd exposure were examined. Our results showed that mortality of gypsy moth larvae caused by B. thuringiensis was significantly higher in larvae pre-exposed to Cd stress, and there was a synergistic effect between Cd pre-exposure and bacterial infection. Exposure to Cd significantly decreased the abundance of several probiotics (e.g., Serratia for the low Cd dosage and Weissella, Aeroonas, and Serratia for the high Cd dosage) and increased the abundances of several pathogenic bacteria (e.g., Stenotrophomonas, Gardnerella, and Cutibacterium for the low Cd dosage and Pluralibacter and Tsukamurella for the high Cd dosage) compared to the controls. Moreover, metabolomics analysis indicated that amino acid biosynthesis and metabolism were significantly perturbed in larval hemolymph under Cd exposure at both the low and high dosages. Correlation analysis demonstrated that several altered metabolites in larval hemolymph were significantly correlated with changes in the gut microbial community. The results demonstrate that prior exposure to Cd increases the susceptibility of gypsy moth larvae to B. thuringiensis in a synergistic fashion due to gut microbiota dysbiosis and hemolymph metabolic disorder, and thus microbial-based biological control may be the best pest control strategy in heavy metal-polluted areas.


Assuntos
Bacillus thuringiensis , Microbioma Gastrointestinal , Mariposas , Animais , Bacillus thuringiensis/fisiologia , Cádmio/toxicidade , Disbiose , Hemolinfa , Larva/microbiologia , Mariposas/fisiologia
15.
Bull Entomol Res ; 112(4): 567-573, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35670157

RESUMO

Carposina sasakii Matsumura (Lepidoptera: Carposinidae) is an important pest of fruit trees in a large area of Asia. The adults mainly depend on olfaction to communicate with the environment, but the olfactory mechanism has not been well known. Odorant degrading enzymes (ODEs) are important olfactory proteins, which inactivate and degrade odorants to free odorant receptors for maintaining olfactory sensitivity. Carboxylesterases (CXEs) are considered to be a major group of moth ODEs. In this study, four candidate CXEs (CsasCXE1 ~ CsasCXE4) were identified by using head transcriptomic data from C. sasakii adult females and males. Sequence alignment showed conserved amino acid residues and their variations in C. sasakii CXEs. Phylogenetic analysis indicated the CXEs with the variations cluster well, and each C. sasakii CXE clusters in a clade with some of the other lepidopteran CXEs, with a high enough bootstrap value. Gene expression analysis revealed that CsasCXE2 and CsasCXE3 have similar tissue and sex expression patterns in C. sasakii adults. The two CXEs have relatively high expression levels in the heads and are expressed more abundantly in the female heads than male heads. CsasCXE1 and CsasCXE4 are expressed at higher levels in the male heads than female heads, but not dominantly expressed in the heads among the different tissues. Whether these CXEs function as ODEs remains to be further researched. This study laid the foundation for exploring functions of C. sasakii CXEs.


Assuntos
Mariposas , Receptores Odorantes , Animais , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Feminino , Frutas , Proteínas de Insetos/metabolismo , Masculino , Mariposas/fisiologia , Filogenia , Receptores Odorantes/metabolismo
16.
Elife ; 112022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35758646

RESUMO

During flight maneuvers, insects exhibit compensatory head movements which are essential for stabilizing the visual field on their retina, reducing motion blur, and supporting visual self-motion estimation. In Diptera, such head movements are mediated via visual feedback from their compound eyes that detect retinal slip, as well as rapid mechanosensory feedback from their halteres - the modified hindwings that sense the angular rates of body rotations. Because non-Dipteran insects lack halteres, it is not known if mechanosensory feedback about body rotations plays any role in their head stabilization response. Diverse non-Dipteran insects are known to rely on visual and antennal mechanosensory feedback for flight control. In hawkmoths, for instance, reduction of antennal mechanosensory feedback severely compromises their ability to control flight. Similarly, when the head movements of freely flying moths are restricted, their flight ability is also severely impaired. The role of compensatory head movements as well as multimodal feedback in insect flight raises an interesting question: in insects that lack halteres, what sensory cues are required for head stabilization? Here, we show that in the nocturnal hawkmoth Daphnis nerii, compensatory head movements are mediated by combined visual and antennal mechanosensory feedback. We subjected tethered moths to open-loop body roll rotations under different lighting conditions, and measured their ability to maintain head angle in the presence or absence of antennal mechanosensory feedback. Our study suggests that head stabilization in moths is mediated primarily by visual feedback during roll movements at lower frequencies, whereas antennal mechanosensory feedback is required when roll occurs at higher frequency. These findings are consistent with the hypothesis that control of head angle results from a multimodal feedback loop that integrates both visual and antennal mechanosensory feedback, albeit at different latencies. At adequate light levels, visual feedback is sufficient for head stabilization primarily at low frequencies of body roll. However, under dark conditions, antennal mechanosensory feedback is essential for the control of head movements at high frequencies of body roll.


Assuntos
Voo Animal , Mariposas , Animais , Retroalimentação , Retroalimentação Sensorial/fisiologia , Voo Animal/fisiologia , Movimentos da Cabeça , Mariposas/fisiologia
17.
Proc Natl Acad Sci U S A ; 119(25): e2117485119, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35704762

RESUMO

Warning signals are well known in the visual system, but rare in other modalities. Some moths produce ultrasonic sounds to warn bats of noxious taste or to mimic unpalatable models. Here, we report results from a long-term study across the globe, assaying moth response to playback of bat echolocation. We tested 252 genera, spanning most families of large-bodied moths, and document anti-bat ultrasound production in 52 genera, with eight subfamily origins described. Based on acoustic analysis of ultrasonic emissions and palatability experiments with bats, it seems that acoustic warning and mimicry are the raison d'être for sound production in most moths. However, some moths use high-duty-cycle ultrasound capable of jamming bat sonar. In fact, we find preliminary evidence of independent origins of sonar jamming in at least six subfamilies. Palatability data indicate that jamming and warning are not mutually exclusive strategies. To explore the possible organization of anti-bat warning sounds into acoustic mimicry rings, we intensively studied a community of moths in Ecuador and, using machine-learning approaches, found five distinct acoustic clusters. While these data represent an early understanding of acoustic aposematism and mimicry across this megadiverse insect order, it is likely that ultrasonically signaling moths comprise one of the largest mimicry complexes on earth.


Assuntos
Mimetismo Biológico , Ecolocação , Reação de Fuga , Mariposas , Acústica , Animais , Mimetismo Biológico/fisiologia , Quirópteros/fisiologia , Ecolocação/fisiologia , Reação de Fuga/fisiologia , Mariposas/classificação , Mariposas/fisiologia , Filogenia , Comportamento Predatório/fisiologia , Piridinas , Ultrassom
18.
Sci Rep ; 12(1): 10405, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35729318

RESUMO

RNA interference (RNAi) triggered by exogenous double-stranded RNA (dsRNA) is a powerful tool to knockdown genetic targets crucial for the growth and development of agriculturally important insect pests. Helicoverpa armigera is a pest feeding on more than 30 economically important crops worldwide and a major threat. Resistance to insecticides and Bt toxins has been gradually increasing in the field. RNAi-mediated knockdown of H. armigera genes by producing dsRNAs homologous to genetic targets in bacteria and plants has a high potential for insect management to decrease agricultural loss. The acetylcholinesterase (AChE), ecdysone receptor (EcR) and v-ATPase-A (vAA) genes were selected as genetic targets. Fragments comprising a coding sequence of < 500 bp were cloned into the L4440 vector for dsRNA production in bacteria and in a TRV-VIGS vector in antisense orientation for transient expression of dsRNA in Solanum tuberosum leaves. After ingesting bacterial-expressed dsRNA, the mRNA levels of the target genes were significantly reduced, leading to mortality and abnormal development in larva of H. armigera. Furthermore, the S. tuberosum plants transformed with TRV-VIGS expressing AChE exhibited higher mortality > 68% than the control plants 17%, recorded ten days post-feeding and significant resistance in transgenic (transient) plants was observed. Moreover, larval lethality and molting defects were observed in larva fed on potato plants expressing dsRNA specific to EcR. Analysis of transcript levels by quantitative RT-PCR revealed that larval mortality was attributable to the knockdown of genetic targets by RNAi. The results demonstrated that down-regulation of H. armigera genes involved in ATP hydrolysis, transcriptional stimulation of development genes and neural conduction has aptitude as a bioinsecticide to control H. armigera population sizes and therefore decreases crop loss.


Assuntos
Mariposas , Solanum tuberosum , Acetilcolinesterase/genética , Animais , Ingestão de Alimentos , Larva/fisiologia , Mariposas/fisiologia , Interferência de RNA , RNA de Cadeia Dupla/genética , Solanum tuberosum/genética
19.
Oecologia ; 199(2): 397-405, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35650412

RESUMO

Plant induced defenses may benefit plants by increasing cannibalism among insect herbivores. However, the general efficacy of plant defenses that promote cannibalism remains unclear. Using a generalist Lepidopteran herbivore (Helicoverpa zea), we examined whether plant induced defenses in Solanum lycopersicum increased cannibalism among H. zea and whether defense-mediated cannibalism benefits both the plant and the cannibal. In a separate experiment, we also examined whether defense-mediated cannibalism has effects on H. zea herbivory that are comparable to the effects of pathogenic virus of H. zea (HzSNPV) and whether defense-mediated cannibalism modified pathogen efficacy. We found that both plant defenses and cannibalism decreased herbivory: H. zea consumed less plant material if plants were induced, if dead conspecifics were provided, or both. Cannibalism increased cannibal growth rate: cannibals effectively overcome the costs of plant defenses by eating conspecifics. Inoculating half of H. zea with virus strongly reduced caterpillar survival. Cannibalism occurred sooner among virus-inoculated groups of H. zea, and all caterpillars in virus-inoculated treatments died before the end of the 7-day experiment. Although the rise in mortality caused by HzSNPV occurred more rapidly than the rise in mortality due to defense-mediated cannibalism, overall H. zea mortality at the end of the experiment was equal among virus-inoculated and induced-defense groups. Defense-mediated cannibalism and viral inoculation equally reduced herbivory on S. lycopersicum. Our results provide evidence that defense-mediated increases in cannibalism can be as effective as other forms of classic herbivore population regulation, and that both viral pathogens and defense-induced cannibalism can have significant benefits for plants.


Assuntos
Lycopersicon esculentum , Mariposas , Animais , Canibalismo , Herbivoria , Larva , Mariposas/fisiologia , Folhas de Planta
20.
Sci Total Environ ; 838(Pt 1): 155800, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35550902

RESUMO

Environmental pollution is one of the major drivers of the present-day decline in global biodiversity. However, the links between the effects of industrial pollution on insect communities and the underlying species-specific responses remain poorly understood. We explored the spatial pattern in insect communities by analysing 581 samples of moths and butterflies (containing 25,628 individuals of 345 species) collected along a strong pollution gradient in subarctic Russia, and we recorded temporal changes in these communities during the pollution decline that occurred from 1992 to 2006. In the 1990s, the diversity of the Lepidoptera community was positively correlated with the distance from the copper-nickel smelter at Monchegorsk. The overall abundance of Lepidoptera did not change along the pollution gradient, although the abundance of many species decreased with increasing pollution. The responses of each individual species to pollution were associated with its life history traits. The abundances of monophagous species that fed inside live plant tissues and hibernated as imagoes or pupae were not affected by pollution, whereas the abundances of oligophagous and polyphagous species that fed externally on plants and hibernated as larvae generally declined near the smelter. Substantial decreases in aerial emissions from the smelter between 1992 and 2006 resulted in an increase in the diversity of moths and butterflies in severely polluted habitats, whereas their overall abundance did not change. This recovery of the Lepidoptera community occurred due to the reappearance of rare species that had been previously extirpated by pollution and was observed despite the lack of any signs of recovery of the vegetation in the heavily polluted sites. We conclude that the recovery trajectories of insect communities following emission control can be predicted from studies of their changes along spatial pollution gradients by using space-for-time substitution.


Assuntos
Borboletas , Mariposas , Animais , Biodiversidade , Ecossistema , Poluição Ambiental , Insetos/fisiologia , Mariposas/fisiologia
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