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1.
J Vis Exp ; (169)2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33779610

RESUMO

Makerspaces have a high potential of enabling researchers to develop new techniques and to work with novel species in ecological research. This protocol demonstrates how to take advantage of the technology found in makerspaces in order to build a more versatile flight mill for a relatively low cost. Given that this study extracted its prototype from flight mills built in the last decade, this protocol focuses more on outlining divergences made from the simple, modern flight mill. Previous studies have already shown how advantageous flight mills are to measuring flight parameters such as speed, distance, or periodicity. Such mills have allowed researchers to associate these parameters with morphological, physiological, or genetic factors. In addition to these advantages, this study discusses the benefits of using the technology in makerspaces, like 3D printers and laser cutters, in order to build a more flexible, sturdy, and collapsible flight mill design. Most notably, the 3D printed components of this design allow the user to test insects of various sizes by making the heights of the mill arm and infrared (IR) sensors adjustable. The 3D prints also enable the user to easily disassemble the machine for quick storage or transportation to the field. Moreover, this study makes greater use of magnets and magnetic paint to tether insects with minimal stress. Lastly, this protocol details a versatile analysis of flight data through computer scripts that efficiently separate and analyze differentiable flight trials within a single recording. Although more labor-intensive, applying the tools available in makerspaces and on online 3D modeling programs facilitates multidisciplinary and process-orientated practices and helps researchers avoid costly, premade products with narrowly adjustable dimensions. By taking advantage of the flexibility and reproducibility of technology in makerspaces, this protocol promotes creative flight mill design and inspires open science.


Assuntos
Voo Animal/fisiologia , Insetos/fisiologia , Animais
2.
Nat Commun ; 12(1): 1650, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33712621

RESUMO

Overhunting reduces important plant-animal interactions such as vertebrate seed dispersal and seed predation, thereby altering plant regeneration and even above-ground biomass. It remains unclear, however, if non-hunted species can compensate for lost vertebrates in defaunated ecosystems. We use a nested exclusion experiment to isolate the effects of different seed enemies in a Bornean rainforest. In four of five tree species, vertebrates kill many seeds (13-66%). Nonetheless, when large mammals are excluded, seed mortality from insects and fungi fully compensates for the lost vertebrate predation, such that defaunation has no effect on seedling establishment. The switch from seed predation by generalist vertebrates to specialist insects and fungi in defaunated systems may alter Janzen-Connell effects and density-dependence in plants. Previous work using simulation models to explore how lost seed dispersal will affect tree species composition and carbon storage may require reevaluation in the context of functional redundancy within complex species interactions networks.


Assuntos
Florestas , Fungos/fisiologia , Insetos/fisiologia , Comportamento Predatório/fisiologia , Sementes , Animais , Ecossistema , Comportamento Alimentar/fisiologia , Herbivoria , Mamíferos , Árvores/microbiologia , Clima Tropical , Vertebrados
3.
Nat Commun ; 12(1): 1690, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727549

RESUMO

Artificial light at night has rapidly spread around the globe over the last decades. Evidence is increasing that it has adverse effects on the behavior, physiology, and survival of animals and plants with consequences for species interactions and ecosystem functioning. For example, artificial light at night disrupts plant-pollinator interactions at night and this can have consequences for the plant reproductive output. By experimentally illuminating natural plant-pollinator communities during the night using commercial street-lamps we tested whether light at night can also change interactions of a plant-pollinator community during daytime. Here we show that artificial light at night can alter diurnal plant-pollinator interactions, but the direction of the change depends on the plant species. We conclude that the effect of artificial light at night on plant-pollinator interactions is not limited to the night, but can also propagate to the daytime with so far unknown consequences for the pollinator community and the diurnal pollination function and services they provide.


Assuntos
Ritmo Circadiano/efeitos da radiação , Plantas/efeitos da radiação , Polinização/efeitos da radiação , Animais , Insetos/fisiologia
4.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33638986

RESUMO

Vernonia [Vernonia galamensis (Cass.) Less.] (Asterales: Asteraceae) was examined as a potential trap crop for the cotton (Gossypium hirsutum L., Malvales: Malvaceae) arthropod complex. Four rows of vernonia were embedded within a 96-row cotton field. The abundance of true bug pests, true bug predators, and spiders were determined by whole-plant and sweep net sampling procedures during the early, middle, and late phases of the cotton-growing season. The census data showed that the arthropods had a strong preference for the vernonia trap crop throughout the cotton-growing season. The movement of the arthropods from the trap crop into cotton was also measured using the protein immunomarking technique as a mark-capture procedure. The arthropods inhabiting the vernonia trap crop were marked directly in the field with a broadcast spray application of egg albumin (protein) during each phase of the study. In turn, the captured specimens were examined for the presence of the mark by an egg albumin-specific enzyme-linked immunosorbent assay. Very few marked specimens were captured beyond the vernonia trap crop 1, 3, and 6 d after each marking event. The arthropods' strong attraction and fidelity to vernonia indicate that it could serve as a trap crop for cotton pests and a refuge for natural enemies.


Assuntos
Distribuição Animal , Controle de Insetos/métodos , Insetos/fisiologia , Traços de História de Vida , Aranhas/fisiologia , Vernonia , Animais , Arizona , Produção Agrícola , Gossypium/crescimento & desenvolvimento , Vernonia/crescimento & desenvolvimento
5.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33620485

RESUMO

The lacewing Chrysoperla sinica (Tjeder) is a common natural enemy of many insect pests in China and is frequently employed for biological control programs. Adults make migratory flights after emergence, which reduces their effectiveness as biological control agents. Previously, we proved that 2-d-old unmated females exhibited significantly stronger flight ability than 3-d-old ones. Meanwhile, 3-d-old unmated adults flew significantly longer distances than mated ones. In this study, Illumina RNA sequencing was performed to characterize differentially expressed genes (DEGs) between virgin and mated adults of different ages in a single female strain of C. sinica. In total, 713,563,726 clean reads were obtained and de novo assembled into 109,165 unigenes with an average length of 847 bp (N50 of 1,754 bp), among which 4,382 (4.01%) unigenes matched known proteins. Based on these annotations, many putative transcripts were related to C. sinica's flight capacity and muscle structure, energy supply, growth, development, environmental adaptability, and metabolism of nutritional components and bioactive components. In addition, the differential expression of transcripts between different ages and mating status were analyzed, and DEGs participating in flight capacity and muscles were detected, including glutathione hydrolase, NAD-specific glutamate dehydrogenase, aminopeptidase, and acidic amino acid decarboxylase. The DEGs with functions associated with flight capacity and muscles exhibited higher transcript levels for younger (2 d--old) virgins. This comprehensive C. sinica transcriptomic data provide a foundation for a better understanding of the molecular mechanisms underlying the flight capacity to meet the physiological demands of flight muscles in C. sinica.


Assuntos
Voo Animal , Genes de Insetos/genética , Insetos/fisiologia , Transcriptoma/fisiologia , Animais , Insetos/genética
6.
Annu Rev Entomol ; 66: 45-60, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33417824

RESUMO

Insect cuticular hydrocarbons (CHCs) consist of complex mixtures of straight-chain alkanes and alkenes, and methyl-branched hydrocarbons. In addition to restricting water loss through the cuticle and preventing desiccation, they have secondarily evolved to serve a variety of functions in chemical communication and play critical roles as signals mediating the life histories of insects. In this review, we describe the physical properties of CHCs that allow for both waterproofing and signaling functions, summarize their roles as inter- and intraspecific chemical signals, and discuss the influences of diet and environment on CHC profiles. We also present advances in our understanding of hydrocarbon biosynthesis. Hydrocarbons are biosynthesized in oenocytes and transported to the cuticle by lipophorin proteins. Recent work on the synthesis of fatty acids and their ultimate reductive decarbonylation to hydrocarbons has taken advantage of powerful new tools of molecular biology, including genomics and RNA interference knockdown of specific genes, to provide new insights into the biosynthesis of hydrocarbons.


Assuntos
Hidrocarbonetos/química , Insetos/química , Comunicação Animal , Animais , Hidrocarbonetos/metabolismo , Insetos/fisiologia
7.
Proc Biol Sci ; 287(1941): 20201663, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33323084

RESUMO

There is a growing appreciation that insect distribution and abundance are associated with the limits of thermal tolerance, but the physiology underlying thermal tolerance remains poorly understood. Many insects, like the migratory locust (Locusta migratoria), suffer a loss of ion and water balance leading to hyperkalaemia (high extracellular [K+]) in the cold that indirectly causes cell death. Cells can die in several ways under stress, and how they die is of critical importance to identifying and understanding the nature of thermal adaptation. Whether apoptotic or necrotic cell death pathways are responsible for low-temperature injury is unclear. Here, we use a caspase-3 specific assay to indirectly quantify apoptotic cell death in three locust tissues (muscle, nerves and midgut) following prolonged chilling and recovery from an injury-inducing cold exposure. Furthermore, we obtain matching measurements of injury, extracellular [K+] and muscle caspase-3 activity in individual locusts to gain further insight into the mechanistic nature of chilling injury. We found a significant increase in muscle caspase-3 activity, but no such increase was observed in either nervous or gut tissue from the same animals, suggesting that chill injury primarily relates to muscle cell death. Levels of chilling injury measured at the whole animal level, however, were strongly correlated with the degree of haemolymph hyperkalaemia, and not apoptosis. These results support the notion that cold-induced ion balance disruption triggers cell death but also that apoptosis is not the main form of cell damage driving low-temperature injury.


Assuntos
Temperatura Baixa , Hiperpotassemia , Insetos/fisiologia , Aclimatação , Animais , Apoptose , Sistema Digestório , Hemolinfa , Locusta migratoria , Potássio , Equilíbrio Hidroeletrolítico
8.
Sci Rep ; 10(1): 22341, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339887

RESUMO

Most plants are subjected to damage from multiple species of herbivores, and the combined impact on plant growth can be non-additive. Since plant response to herbivores tends to be species specific, and change with repeated damage, the outcome likely depend on the sequence and number of attacks. There is a high likelihood of non-additive effects on plant growth by damage from mammals and insects, as mammalian herbivory can alter insect herbivore damage levels, yet few studies have explored this. We report the growth response of young Scots pine trees to sequential mammal and insect herbivory, varying the sequence and number of damage events, using an ungulate-pine-sawfly system. Combined sawfly and ungulate herbivory had both additive and non-additive effects on pine growth-the growth response depended on the combination of ungulate browsing and sawfly defoliation (significant interaction effect). Repeated sawfly herbivory reduced growth (compared to single defoliation) on un-browsed trees. However, on browsed trees, depending on when sawfly defoliation was combined with browsing, trees exposed to repeated sawfly herbivory had both higher, lower and the same growth as trees exposed to a single defoliation event. We conclude that the sequence of attacks by multiple herbivores determine plant growth response.


Assuntos
Herbivoria/fisiologia , Insetos/fisiologia , Pinus/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Animais , Humanos , Insetos/patogenicidade , Mamíferos
9.
PLoS One ; 15(12): e0244005, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382722

RESUMO

Rapidly detecting and responding to new invasive species and the spread of those that are already established is essential for reducing their potential threat to food production, the economy, and the environment. We describe a new spatial modeling platform that integrates mapping of phenology and climatic suitability in real-time to provide timely and comprehensive guidance for stakeholders needing to know both where and when invasive insect species could potentially invade the conterminous United States. The Degree-Days, Risk, and Phenological event mapping (DDRP) platform serves as an open-source and relatively easy-to-parameterize decision support tool to help detect new invasive threats, schedule monitoring and management actions, optimize biological control, and predict potential impacts on agricultural production. DDRP uses a process-based modeling approach in which degree-days and temperature stress are calculated daily and accumulate over time to model phenology and climatic suitability, respectively. Outputs include predictions of the number of completed generations, life stages present, dates of phenological events, and climatically suitable areas based on two levels of climate stress. Species parameter values can be derived from laboratory and field studies or estimated through an additional modeling step. DDRP is written entirely in R, making it flexible and extensible, and capitalizes on multiple R packages to generate gridded and graphical outputs. We illustrate the DDRP modeling platform and the process of model parameterization using two invasive insect species as example threats to United States agriculture: the light brown apple moth, Epiphyas postvittana, and the small tomato borer, Neoleucinodes elegantalis. We then discuss example applications of DDRP as a decision support tool, review its potential limitations and sources of model error, and outline some ideas for future improvements to the platform.


Assuntos
Biomassa , Clima , Simulação por Computador , Insetos/fisiologia , Espécies Introduzidas , Parasitos/fisiologia , Animais , Mapeamento Geográfico , Insetos/patogenicidade , Parasitos/patogenicidade , Análise Espaço-Temporal
10.
Proc Biol Sci ; 287(1931): 20200975, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-33043864

RESUMO

Alternative mating strategies are widespread among animal taxa, with strategies controlled by a genetic polymorphism (Mendelian strategy) being rarer in nature than condition-dependent developmental strategies. Mendelian strategies are predicted to have equal average fitnesses and the proportion of offspring produced by a strategy should equal the equilibrium proportion of individuals representing the strategy in a population. Developmental strategies are not expected to produce offspring in equilibrium proportions; however, whether the alternative phenotypes should have equal average fitness is debated. The Wellington tree weta (Hemideina crassidens) (Orthoptera: Anostostomatidae) is a harem polygynous insect in which intense sexual competition has favoured the evolution of three alternative mating strategies that differ in weapon size and the ability to fight for control of harems. Here, we use molecular genotyping to test the hypothesis that the alternative strategies in this species are maintained by having equal relative fitness and that morphs produce offspring in equilibrium proportions. As expected, the average relative fitness of the three strategies did not significantly differ and the proportion of offspring produced by each morph is equal to the frequency of that morph in the population. Our results support the hypothesis that the alternative male morphs in H. crassidens represent Mendelian strategies.


Assuntos
Insetos/fisiologia , Comportamento Sexual Animal , Animais , Feminino , Masculino , Ortópteros , Fenótipo , Polimorfismo Genético , Seleção Genética
11.
Nat Commun ; 11(1): 5316, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082335

RESUMO

A comparative analysis of animal behavior (e.g., male vs. female groups) has been widely used to elucidate behavior specific to one group since pre-Darwinian times. However, big data generated by new sensing technologies, e.g., GPS, makes it difficult for them to contrast group differences manually. This study introduces DeepHL, a deep learning-assisted platform for the comparative analysis of animal movement data, i.e., trajectories. This software uses a deep neural network based on an attention mechanism to automatically detect segments in trajectories that are characteristic of one group. It then highlights these segments in visualized trajectories, enabling biologists to focus on these segments, and helps them reveal the underlying meaning of the highlighted segments to facilitate formulating new hypotheses. We tested the platform on a variety of trajectories of worms, insects, mice, bears, and seabirds across a scale from millimeters to hundreds of kilometers, revealing new movement features of these animals.


Assuntos
Aves/fisiologia , Aprendizado Profundo , Insetos/fisiologia , Camundongos/fisiologia , Ursidae/fisiologia , Animais , Comportamento Animal , Feminino , Movimento , Redes Neurais de Computação , Software
12.
PLoS One ; 15(10): e0239847, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095792

RESUMO

Green lacewings (Neuroptera: Chrysopidae) are key biological control agents found in a broad range of crops. Given the importance of enhancing their presence and conservation, in this study, we aim to identify and to determine the relative importance of the pollen consumed by Chrysoperla lucasina (Lacroix, 1936) from 29 pollen types offered by 51 native plant species sown in an experimental farm in Villarrubia in the south of Spain. For the purposes of this study, C. lucasina specimens were captured in the late spring of 2016 and 2017. The pollen types and other components in the alimentary canal of C. lucasina were microscopically identified using the transparency method, which is a novel technique applied to green lacewings captured in the field. The results show that (i) C. lucasina feeds on over half of the pollen types offered by the sown plant species, with no differences in behaviour by sex or year; (ii) Capsella bursa-pastoris was the most frequently identified pollen type in the alimentary canal; (iii) the majority of pollen types identified correspond to sown native plant species and not to surrounding plant species; and that (iv) most of the adults studied also consumed honeydew. Our feeding study has important implications for the selection of plant mixtures for ground cover restoration and flower vegetation strips in Mediterranean agroecosystems, which complements our previous findings on how C. lucasina use native plant species as host and reproduction sites. The plant species Capsella bursa-pastoris and Biscutella auriculata, which are best suited to provide pollen, host and reproduction sites for C. lucasina in late spring, should consequently be included in the proposed plant mixtures for Mediterranean agroecosystems.


Assuntos
Dieta , Insetos/fisiologia , Pólen/classificação , Polinização , Animais , Feminino , Magnoliopsida , Masculino
13.
PLoS One ; 15(9): e0238916, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941477

RESUMO

BACKGROUND: Field margins are ecologically important to an agroecosystem as they are a source of biodiversity. They can be composed of a diverse flora which may offer resources to a wide range of insects and birds. The vegetation composition of field margins is determined by soil characteristics, management, and landscape structures. However, little is known about the effect of individual field margin components such as ditches, grass strips, shrubs and trees, and the overall margin's complexity, on the vegetation composition and its functional effect and response traits. METHODS: This paper reports on the effects of field margin component typology (ditches, grass strips, shrubs, trees, and vehicle tracks) and complexity (the number of components), on the herbaceous vegetation of field margins. Forty field margins were sampled in 2016 in a 200 ha. organic mixed arable livestock farm. RESULTS: The factor which was identified as having the most effect on vegetation composition was adjacent land-use type, which reflected the margins' management regime. However, field margin components were found to affect vegetation response and effect traits. Tree components had less grassweeds than vehicle tracks while more complex field margins also had less grassweeds than simple field margins near cropped fields, most likely due to the lower availability in light and less disturbance from vehicles. Simple grassy margins produced a high proportion of hymenoptera flowers. DISCUSSION: These results highlight the importance of field margin components in maintaining a high diversity of vegetation typologies differing in effect traits that are relevant for the provisioning of ecosystem services, such as supporting pollen and nectar requirements of beneficial insects, as well as their importance in determining the presence of weed species that could potentially invade the cropped fields.


Assuntos
Agricultura/métodos , Poaceae/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Animais , Biodiversidade , Aves/fisiologia , Conservação dos Recursos Naturais , Insetos/fisiologia , Itália , Plantas Daninhas/crescimento & desenvolvimento
14.
Proc Natl Acad Sci U S A ; 117(34): 20653-20661, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32778582

RESUMO

While the impact of air pollution on human health is well studied, mechanistic impacts of air pollution on wild systems, including those providing essential ecosystem services, are largely unknown, but directly impact our health and well-being. India is the world's largest fruit producer, second most populous country, and contains 9 of the world's 10 most polluted cities. Here, we sampled Giant Asian honey bees, Apis dorsata, at locations with varying air pollution levels in Bangalore, India. We observed significant correlations between increased respirable suspended particulate matter (RSPM) deposition and changes in bee survival, flower visitation, heart rate, hemocyte levels, and expression of genes related to lipid metabolism, stress, and immunity. Lab-reared Drosophila melanogaster exposed to these same sites also exhibited similar molecular and physiological differences. Our study offers a quantitative analysis on the current impacts of air pollution on insects, and indicates the urgency for more nonhuman studies to accurately assess the effects of pollution on our natural world.


Assuntos
Poluição do Ar/efeitos adversos , Abelhas/fisiologia , Polinização/fisiologia , Animais , Abelhas/efeitos dos fármacos , Cidades , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/fisiologia , Ecossistema , Estudos de Avaliação como Assunto , Humanos , Índia , Insetos/fisiologia , Material Particulado/efeitos adversos
15.
Nat Commun ; 11(1): 4086, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796828

RESUMO

Ecological communities often show changes in populations and their interactions over time. To date, however, it has been challenging to effectively untangle the mechanisms shaping such dynamics. One approach that has yet to be fully explored is to treat the varying structure of empirical communities-i.e. their network of interactions-as time series. Here, we follow this approach by applying a network-comparison technique to study the seasonal dynamics of plant-pollinator networks. We find that the structure of these networks is extremely variable, where species constantly change how they interact with each other within seasons. Most importantly, we find the holistic dynamic of plants and pollinators to be remarkably coherent across years, allowing us to reveal general rules by which species first enter, then change their roles, and finally leave the networks. Overall, our results disentangle key aspects of species' interaction turnover, phenology, and seasonal assembly/disassembly processes in empirical plant-pollinator communities.


Assuntos
Polinização/fisiologia , Animais , Biodiversidade , Biota , Insetos/fisiologia , Estações do Ano
16.
Chemosphere ; 260: 127620, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32758770

RESUMO

Developing an eco-friendly Integrated Pest Management (IPM) approach is only possible by minimizing the use of insecticides and their effects on non-targets such as natural enemies. Chrysoperla carnea is a potential predator of several economic pests including whiteflies and aphids. C. carnea selected with cyromazine for 15 generations indicated a great increase in resistance to this Insect Growth Regulator (IGR). There was no cross-resistance to chlorpyrifos, cypermethrin and nitenpyram in Cyro-SEL population. Inheritance to cyromazine was autosomal, incompletely dominant, and polygenic. A high realized heritability (h2) value (0.37) confirmed more genetic variability. Synergists piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) showed a significant involvement of P-450 monooxygenase and esterase in cyromazine resistance development. These findings are helpful to design a natural enemy-friendly IPM strategy resulting in increased survival and performance of C. carnea controlling economic pests.


Assuntos
Insetos/fisiologia , Inseticidas/toxicidade , Triazinas/toxicidade , Animais , Afídeos/efeitos dos fármacos , Clorpirifos/farmacologia , Insetos/efeitos dos fármacos , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Neonicotinoides , Butóxido de Piperonila/farmacologia , Piretrinas
17.
Ecotoxicology ; 29(9): 1358-1367, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32851565

RESUMO

Integrated Pest Management programs do not always prioritize natural enemies when selecting control methods; too often these important pest reducing agents are negatively affected by the action of other methods in agroecosystems. The aim of this research was to evaluate side effects of a bioinsecticide, developed from the mixture of cedar (Cedrus atlantica), eucalyptus (Corymbia citriodora) and lemon grass (Cymbopogon citratus) essential oils (EOs), in a ratio of 1:1:1, on Psyttalia concolor (Szèpligeti) (Hymenoptera: Braconidae) which is a parasitoid of some pests of the Tephritidae family, as Ceratitis capitata. The LD50 of the EOs mixture for C. capitata females was 3.09 µl/g, whereas the LD50 for P. concolor females was 20.45 µl/g which suggests the natural enemy is more tolerant to the EOs mixture. P. concolor parasitized L3 larvae of C. capitata through a voile treated with the mixture of EOs at 1.8% without causing any deleterious effects neither on the percentage of attacked hosts nor on the emergence rate, whereas at the highest concentration tested, 4.8%, decreased both parameters during the 2 first days after treatment. Semi-field assays showed that mixture of EOs was harmless to P. concolor when released 4 h after treatment whereas killed 55 ± 3.9% males and 37.5 ± 1.6% females of C. capitata. The mixture of EOs used jointly with lambda-cyhalothrin or kaolin, both compounds applied against C. capitata in conventional and organic farming, respectively, did not increase the toxicity and/or persistence against the pest.


Assuntos
Insetos/fisiologia , Óleos Voláteis/toxicidade , Controle de Pragas/métodos , Animais , Feminino , Masculino
18.
PLoS One ; 15(7): e0229476, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649703

RESUMO

Recent debates on insect decline require sound assessments on the relative drivers that may negatively impact insect populations. Often, baseline data rely on insect monitorings that integrate catches over long time periods. If, however, effects of time-critical environmental factors (e.g., light pollution) are of interest, higher temporal resolution of insect data is required during very specific time intervals (e.g., between dusk and dawn). Conventional time-critical insect trapping is labour-intensive (manual activation/deactivation) and temporally inaccurate as not all traps can be serviced synchronically at different sites. Also, temporal shifts of environmental conditions (e.g., sunset/sunrise) are not accounted for. We present a battery-driven automated insect flight-interception trap which samples insects during seven user-defined time intervals. A commercially available flight-interception trap is fitted to a turntable containing eight positions, seven of them holding cups and one consisting of a pass-through hole. While the cups sample insects during period of interest, the pass-through hole avoids unwanted sampling during time-intervals not of interest. Comparisons between two manual and two automated traps during 71 nights in 2018 showed no difference in caught insects. A study using 20 automated traps during 104 nights in 2019 proved that the automated flight-interception traps are reliable. The automated trap opens new research and application possibilities as arbitrary insect-sampling intervals can be defined. The trap proves efficient, saving manpower and associated costs as activation/deactivation is required only every seven sampling intervals. In addition, the timing of the traps is accurate, as all traps sample at exactly the same intervals and ensure comparability. The automated trap is low maintenance and robust due to straightforward technical design. It can be controlled manually or via smartphone through a Bluetooth connection. Full construction details are given in Appendices.


Assuntos
Voo Animal , Controle de Insetos/métodos , Insetos/fisiologia , Animais , Automação , Desenho de Equipamento
19.
Ecotoxicology ; 29(7): 856-865, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32613481

RESUMO

Plutella xylostella, is the main pest infesting Brassica crops, and products based on Bacillus thuringiensis (Bt) are frequently used in strategies for its biocontrol. The present study aimed to evaluate whether a Bt-based bioinsecticide affects the predation behavior of Ceraeochrysa cincta when preying on P. xylostella. Three larval instars of the predator and the eggs and second-instar larvae of the moth were used, with the prey either untreated or treated with a Bt-based product (Xentari®). Results showed that, the first larval instar of C. cincta presented a type II functional response when preying upon untreated eggs, and a type III response when preying upon Bt-treated eggs, while the second and third instars presented type II and III responses, respectively, in both situations. The predator's first and third larval instars presented a type II functional response when preying upon untreated larvae and a type III response when preying upon Bt-treated larvae. However, the predator's second-instar larvae showed a type II response in both treatments. The results obtained allowed us to conclude that the Bt-based insecticide tested affects the predation behavior of the first-instar larvae of C. cincta on eggs and of both the first- and third-instar larvae of this predator on P. xylostella larvae.


Assuntos
Bacillus thuringiensis/química , Controle de Insetos , Insetos/fisiologia , Inseticidas/administração & dosagem , Controle Biológico de Vetores , Comportamento Predatório , Animais , Brasil , Insetos/efeitos dos fármacos , Resistência a Inseticidas , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento
20.
Proc Biol Sci ; 287(1931): 20201273, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32693722

RESUMO

Many insects survive internal freezing, but the great complexity of freezing stress hinders progress in understanding the ultimate nature of freezing-induced injury. Here, we use larvae of the drosophilid fly, Chymomyza costata to assess the role of mitochondrial responses to freezing stress. Respiration analysis revealed that fat body mitochondria of the freeze-sensitive (non-diapause) phenotype significantly decrease oxygen consumption upon lethal freezing stress, while mitochondria of the freeze-tolerant (diapausing, cold-acclimated) phenotype do not lose respiratory capacity upon the same stress. Using transmission electron microscopy, we show that fat body and hindgut mitochondria swell, and occasionally burst, upon exposure of the freeze-sensitive phenotype to lethal freezing stress. By contrast, mitochondrial swelling is not observed in the freeze-tolerant phenotype exposed to the same stress. We hypothesize that mitochondrial swelling results from permeability transition of the inner mitochondrial membrane and loss of its barrier function, which causes osmotic influx of cytosolic water into the matrix. We therefore suggest that the phenotypic transition to diapause and cold acclimation could be associated with adaptive changes that include the protection of the inner mitochondrial membrane against permeability transition and subsequent mitochondrial swelling. Accumulation of high concentrations of proline and other cryoprotective substances might be a part of such adaptive changes as we have shown that freezing-induced mitochondrial swelling was abolished by feeding the freeze-sensitive phenotype larvae on a proline-augmented diet.


Assuntos
Congelamento , Insetos/fisiologia , Mitocôndrias , Aclimatação , Animais , Drosophilidae , Larva/fisiologia
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