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1.
Molecules ; 26(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34361547

RESUMO

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


Assuntos
Antenas de Artrópodes/fisiologia , Comportamento Animal/efeitos dos fármacos , Repelentes de Insetos , Magnoliopsida/química , Óleos Voláteis , Tribolium/fisiologia , Animais , Repelentes de Insetos/química , Repelentes de Insetos/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia
2.
Sci Rep ; 11(1): 1145, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441570

RESUMO

Knockdown and mortality of adults of the red flour beetle, Tribolium castaneum (Herbst) and the confused flour beetle, Tribolium confusum Jacquelin du Val, were assessed after exposure to two contact insecticides, chlorfenapyr and cyfluthrin, on a concrete surface. Individuals were rated on a scale for knockdown of exposed adults according to their mobility from 1, representing immobilized adults to 5, representing normally moving (similar to the controls). Only cyfluthrin gave immediate knockdown. Adults were rated at 1, 3 and 7 days post-exposure. After the final assessment, adults were discarded and the same procedure was repeated for 5 consecutive weeks with new adults exposed on the same treated surfaces. Despite initial knockdown, many individuals did not eventually die after exposure to cyfluthrin. In contrast, adults exposed to chlorfenapyr were not initially knocked down after exposure but most died after 7 days. These trends were similar during the entire 5-week residual testing period. The storage of the treated dishes in illuminated or non-illuminated conditions did not affect the insecticidal effect of either insecticide. The results of the present study can be further implemented towards the design of a "lethality index" that can serve as a quick indicator of knockdown and mortality rates caused after exposure to insecticides.


Assuntos
Inseticidas/toxicidade , Nitrilas/toxicidade , Piretrinas/toxicidade , Tribolium/efeitos dos fármacos , Animais , Movimento/efeitos dos fármacos , Controle de Pragas , Tribolium/fisiologia
3.
PLoS One ; 16(1): e0245115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33444354

RESUMO

Many species show rhythmicity in activity, from the timing of flowering in plants to that of foraging behavior in animals. The free-running periods and amplitude (sometimes called strength or power) of circadian rhythms are often used as indicators of biological clocks. Many reports have shown that these traits are highly geographically variable, and interestingly, they often show latitudinal or longitudinal clines. In many cases, the higher the latitude is, the longer the free-running circadian period (i.e., period of rhythm) in insects and plants. However, reports of positive correlations between latitude or longitude and circadian rhythm traits, including free-running periods, the power of the rhythm and locomotor activity, are limited to certain taxonomic groups. Therefore, we collected a cosmopolitan stored-product pest species, the red flour beetle Tribolium castaneum, in various parts of Japan and examined its rhythm traits, including the power and period of the rhythm, which were calculated from locomotor activity. The analysis revealed that the power was significantly lower for beetles collected in northern areas than southern areas in Japan. However, it is worth noting that the period of circadian rhythm did not show any clines; specifically, it did not vary among the sampling sites, despite the very large sample size (n = 1585). We discuss why these cline trends were observed in T. castaneum.


Assuntos
Relógios Biológicos/fisiologia , Ritmo Circadiano/fisiologia , Tribolium/fisiologia , Animais , Japão
4.
PLoS One ; 15(10): e0239051, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33006995

RESUMO

A large body of ongoing research focuses on understanding the mechanisms and processes underlying host-microbiome interactions, and predicting their ecological and evolutionary outcomes. To draw general conclusions about such interactions and understand how they are established, we must synthesize information from a diverse set of species. We analysed the microbiome of an important insect model-the red flour beetle Tribolium castaneum-which is a widespread generalist pest of stored cereals. The beetles complete their entire life cycle in flour, which thus serves multiple functions: habitat, food, and a source of microbes. We determined key factors that shape the T. castaneum microbiome, established protocols to manipulate it, and tested its consequences for host fitness. We show that the T. castaneum microbiome is derived from flour-acquired microbes, and varies as a function of (flour) resource and beetle density. Beetles gain multiple fitness benefits from their microbiome, such as higher fecundity, egg survival, and lifespan; and reduced cannibalism. In contrast, the microbiome has a limited effect on development rate, and does not enhance pathogen resistance. Importantly, the benefits are derived only from microbes in the ancestral resource (wheat flour), and not from novel resources such as finger millet, sorghum, and corn. Notably, the microbiome is not essential for beetle survival and development under any of the tested conditions. Thus, the red flour beetle is a tractable model system to understand the ecology, evolution and mechanisms of host-microbiome interactions, while closely mimicking the host species' natural niche.


Assuntos
Interações entre Hospedeiro e Microrganismos , Modelos Biológicos , Tribolium/microbiologia , Animais , Antibacterianos/farmacologia , Bacillus thuringiensis/patogenicidade , Canibalismo , Feminino , Fertilidade , Farinha/microbiologia , Farinha/parasitologia , Aptidão Genética , Longevidade , Masculino , Microbiota/efeitos dos fármacos , Microbiota/genética , Microbiota/efeitos da radiação , Tribolium/crescimento & desenvolvimento , Tribolium/fisiologia , Raios Ultravioleta
5.
J Chem Ecol ; 46(11-12): 1032-1046, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33123870

RESUMO

Cuticular hydrocarbons (CHCs) of host insects are used by many parasitic wasps as contact kairomones for host location and recognition. As the chemical composition of CHCs varies from species to species, the CHC pattern represents a reliable indicator for parasitoids to discriminate host from non-host species. Holepyris sylvanidis is an ectoparasitoid of beetle larvae infesting stored products. Previous studies demonstrated that the larval CHC profile of the confused flour beetle, Tribolium confusum, comprises long chain linear and methyl-branched alkanes (methyl alkanes), which elicit trail following and host recognition in H. sylvanidis. Here we addressed the question, whether different behavioral responses of this parasitoid species to larvae of other beetle species are due to differences in the larval CHC pattern. Our study revealed that H. sylvanidis recognizes and accepts larvae of T. confusum, T. castaneum and T. destructor as hosts, whereas larvae of Oryzaephilus surinamensis were rejected. However, the latter species became attractive after applying a sample of T. confusum larval CHCs to solvent extracted larvae. Chemical analyses of the larval extracts revealed that CHC profiles of the Tribolium species were similar in their composition, while that of O. surinamensis differed qualitatively and quantitatively, i.e. methyl alkanes were present as minor components on the cuticle of all Tribolium larvae, but were absent in the O. surinamensis CHC profile. Furthermore, the parasitoid successfully recognized solvent extracted T. confusum larvae as hosts after they had been treated with a fraction of methyl alkanes. Our results show that methyl alkanes are needed for host recognition by H. sylvanidis.


Assuntos
Alcanos/química , Misturas Complexas/química , Hidrocarbonetos/química , Hidrocarbonetos/metabolismo , Larva/parasitologia , Animais , Besouros/fisiologia , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Interações Hospedeiro-Parasita , Comportamento de Busca por Hospedeiro , Larva/metabolismo , Masculino , Especificidade da Espécie , Propriedades de Superfície , Tribolium/fisiologia , Vespas/fisiologia
6.
Insect Biochem Mol Biol ; 126: 103452, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32822817

RESUMO

Although the mechanisms that control growth are now well understood, the mechanism by which animals assess their body size remains one of the great puzzles in biology. The final larval instar of holometabolous insects, after which growth stops and metamorphosis begins, is specified by a threshold size. We investigated the mechanism of threshold size assessment in the tobacco hornworm, Manduca sexta. The threshold size was found to change depending on the amount of exposure to poor nutrient conditions whereas hypoxia treatment consistently led to a lower threshold size. Under these various conditions, the mass of the muscles plus integuments was correlated with the threshold size. Furthermore, the expression of myoglianin (myo) increased at the threshold size in both M. sexta and Tribolium castaneum. Knockdown of myo in T. castaneum led to larvae that underwent supernumerary larval molts and stayed in the larval stage permanently even after passing the threshold size. We propose that increasing levels of Myo produced by the growing tissues allow larvae to assess their body size and trigger metamorphosis at the threshold size.


Assuntos
Manduca/fisiologia , Metamorfose Biológica/fisiologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Tamanho Corporal/fisiologia , Técnicas de Silenciamento de Genes/métodos , Genes de Insetos , Holometábolos/crescimento & desenvolvimento , Holometábolos/fisiologia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Manduca/crescimento & desenvolvimento , Fator de Crescimento Transformador beta/genética , Tribolium/crescimento & desenvolvimento , Tribolium/fisiologia
7.
Insect Biochem Mol Biol ; 126: 103450, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32818622

RESUMO

Insect adult metamorphosis generally proceeds with undetectable levels of juvenile hormone (JH). In adult development of the red flour beetle Tribolium castaneum, biosynthesis of adult cuticle followed by its pigmentation and sclerotization occurs, and dark coloration of the cuticle becomes visible in pharate adults. Here, we examined the molecular mechanism of adult cuticular formation in more detail. We noticed that an exogenous JH mimic (JHM) treatment of Day 0 pupae did not inhibit pigmentation or sclerotization, but instead, induced precocious pigmentation of adult cuticle two days in advance. Quantitative RT-PCR analyses revealed that ecdysone-induced protein 75B (E75) is downregulated in JHM-treated pupae. Meanwhile, tyrosine hydroxylase (Th), an enzyme involved in cuticular pigmentation and sclerotization, was precociously induced, whereas a structural cuticular protein CPR27 was downregulated, by exogenous JHM treatment. RNA interference-mediated knockdown of E75 resulted in precocious adult cuticular pigmentation, which resembled the phenotype caused by JHM treatment. Notably, upregulation of Th as well as suppression of CPR27 were observed with E75 knockdown. Meanwhile, JHM treatment suppressed the expression of genes involved in melanin synthesis, such as Yellow-y and Laccase 2, but E75 knockdown did not result in marked reduction in their expression. Taken together, these results provided insights into the regulatory mechanisms of adult cuticular formation; the transcription of genes involved in adult cuticular formation proceeds in a proper timing with undetectable JH, and exogenous JHM treatment disturbs their transcription. For some of these genes such as Th and CPR27, E75 is involved in transcriptional regulation. This study shed light on the molecular mode of action of JHM as insecticides; exogenous JHM treatment disturbed the expression of genes involved in the adult cuticular formation, which resulted in lethality as pharate adults.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Insetos/metabolismo , Hormônios Juvenis , Metamorfose Biológica , Pigmentação , Receptores de Esteroides/metabolismo , Tribolium , Animais , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Genes de Insetos , Proteínas de Insetos/efeitos dos fármacos , Proteínas de Insetos/genética , Hormônios Juvenis/metabolismo , Hormônios Juvenis/farmacologia , Metamorfose Biológica/genética , Metamorfose Biológica/fisiologia , Pigmentação/genética , Pigmentação/fisiologia , Receptores de Esteroides/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tribolium/genética , Tribolium/metabolismo , Tribolium/fisiologia , Tirosina 3-Mono-Oxigenase/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/metabolismo
8.
PLoS One ; 15(7): e0235289, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645709

RESUMO

Flour beetles are a classic model system for studying competitive dynamics between species occupying the same ecological niche. Competitive performance is often interpreted in terms of biological species traits such as fecundity, resource use, and predation. However, many studies only measure competitive ability when species enter an environment simultaneously, and thus do not consider how the relative timing of species' arrival may determine competitive outcome (i.e., priority effects). Whether priority effects may influence competition in Tribolium remains to be tested. The present study examined the importance of priority effects in competitions between two common species of flour beetle (Coleoptera: Tenebrionidae): Tribolium castaneum and T. confusum. To investigate whether priority effects confer competitive advantages to Tribolium beetles, relative introduction times of T. castaneum and T. confusum to competitive arenas were manipulated, and adult populations were measured for seven months. Four important patterns were noted: (1) Tribolium species given two-weeks priority access to experimental arenas attained larger populations than their late-arriving competitor, (2) when founding adults were introduced simultaneously, T. castaneum was competitively dominant, (3) T. castaneum benefited more from priority arrival than T. confusum, and (4) available bran resources largely predicted population decline in adult beetles toward the end of the experiment. These results suggest competitive outcome in Tribolium is not always predicted by species' identity, and that performance could instead be determined by the timing of species' arrivals and available resources.


Assuntos
Comportamento Competitivo , Meio Ambiente , Alimentos , Tribolium/fisiologia , Envelhecimento/fisiologia , Análise de Variância , Animais , Modelos Lineares , Especificidade da Espécie , Análise de Sobrevida
9.
BMC Genomics ; 21(1): 420, 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32571203

RESUMO

BACKGROUND: Hormones are chemical communication signaling molecules released into the body fluids to stimulate target cells of multicellular organisms. We recently showed that histone deacetylase 1 (HDAC1) plays an important role in juvenile hormone (JH) suppression of metamorphosis in the red flour beetle, Tribolium castaneum. Here, we investigated the function of another class I HDAC member, HDAC3, and show that it is required for the normal development of T. castaneum. RESULTS: RNA interference-mediated knockdown of the HDAC3 gene affected development resulting in abnormally folded wings in pupae and adults. JH analog, hydroprene, suppressed the expression of HDAC3 in T. castaneum larvae. The knockdown of HDAC3 during the final instar larval stage resulted in an increase in the expression of genes coding for proteins involved in JH action. Sequencing of RNA isolated from larvae injected with dsRNA targeting malE (E. coli gene, control) or HDAC3 followed by differential gene expression analysis identified 148 and 741 differentially expressed genes based on the P-value < 0.01 and four-fold difference, and the P-value < 0.05 and two-fold difference, respectively. Several genes, including those coding for myosin-I heavy chain (Myosin 22), Shaven, and nuclear receptor corepressor 1 were identified as differentially expressed genes in HDAC3 knockdown larvae. An increase in histone H3 acetylation, specifically H3K9, H3K18, and H3K27, was detected in HDAC3 knockdown insects. CONCLUSION: Overall, these data suggest that HDAC3 affects the acetylation levels of histones and influences the expression of genes coding for proteins involved in the regulation of growth, development, and metamorphosis.


Assuntos
Perfilação da Expressão Gênica/métodos , Histona Desacetilases/genética , RNA Interferente Pequeno/genética , Tribolium/fisiologia , Acetilação , Animais , Proteínas Correpressoras/genética , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Proteínas de Insetos/genética , Metamorfose Biológica , Miosina Tipo I/genética , RNA Interferente Pequeno/farmacologia , Tribolium/genética
10.
Molecules ; 25(9)2020 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-32397385

RESUMO

: The present work evaluates for the first time two Lavandin (Lavandula × intermedia Emeric ex Loisel.) aromatic waters obtained from different plant organs, the flowers and the stems. Both extracts were analysed by GC-MS, which indicates semi-quantitative differences between the major metabolites including linalool, 1,8-cineole, camphor, linalyl acetate and 4-terpineol. 1H-NMR and LC-MS investigation confirmed the presence of these compounds. Moreover, behavioural tests with the food insect pest Tribolium confusum (Coleoptera Tenebrionidae) showed a good repellency for both hydrosols extracts with RD50 values of 3.6 and 3.3 µL cm-2 for the flowers and stems, respectively; at the higher concentrations, however, the hydrosol extract from the flowers is expected to be more effective than the one from the stems. The effect of the flowers and stems aromatic water of Lavandin on seed germination of Raphanus sativus was also evaluated. Results showed that seed germination was completely inhibited by flowers hydrolate, having a possible application as natural herbicide. The overall experience with these Lavandin extracts indicates the potential of improved hydrolates to become the main distillation products, rather than by-products, of the aromatic plants manufacturing; this stimulates further discussions about the potential positive impacts that such a shift could have in the context of ecopharmacognosy.


Assuntos
Repelentes de Insetos/farmacologia , Lavandula/química , Extratos Vegetais/farmacologia , Tribolium/fisiologia , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/farmacologia , Animais , Cânfora/química , Cânfora/farmacologia , Eucaliptol/química , Eucaliptol/farmacologia , Flores/química , Cromatografia Gasosa-Espectrometria de Massas , Germinação , Repelentes de Insetos/química , Itália , Mentol/análogos & derivados , Mentol/química , Mentol/farmacologia , Monoterpenos/química , Monoterpenos/farmacologia , Óleos Voláteis , Extratos Vegetais/química , Óleos Vegetais , Caules de Planta/química , Raphanus/fisiologia
11.
PLoS Genet ; 16(5): e1008768, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32379753

RESUMO

Gene expression is known to be highly responsive to the environment and important for adjustment of metabolism but there is also growing evidence that differences in gene regulation contribute to species divergence and differences among locally adapted populations. However, most studies so far investigated populations when divergence had already occurred. Selection acting on expression levels at the onset of adaptation to an environmental change has not been characterized. Understanding the mechanisms is further complicated by the fact that environmental change is often multivariate, meaning that organisms are exposed to multiple stressors simultaneously with potentially interactive effects. Here we use a novel approach by combining fitness and whole-transcriptome data in a large-scale experiment to investigate responses to drought, heat and their combination in Tribolium castaneum. We found that fitness was reduced by both stressors and their combined effect was almost additive. Expression data showed that stressor responses were acting independently and did not interfere physiologically. Since we measured expression and fitness within the same individuals, we were able to estimate selection on gene expression levels. We found that variation in fitness can be attributed to gene expression variation and that selection pressures were environment dependent and opposite between control and stress conditions. We could further show that plastic responses of expression were largely adaptive, i.e. in the direction that should increase fitness.


Assuntos
Perfilação da Expressão Gênica/métodos , Proteínas de Insetos/genética , Estresse Fisiológico , Tribolium/fisiologia , Animais , Secas , Feminino , Regulação da Expressão Gênica , Aptidão Genética , Masculino , Análise de Sequência de RNA , Termotolerância , Tribolium/genética
12.
Molecules ; 25(7)2020 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-32235326

RESUMO

Phosphine resistance is a worldwide issue threatening the grain industry. The cuticles of insects are covered with a layer of lipids, which protect insect bodies from the harmful effects of pesticides. The main components of the cuticular lipids are hydrocarbon compounds. In this research, phosphine-resistant and -susceptible strains of two main stored-grain insects, T. castaneum and R. dominica, were tested to determine the possible role of their cuticular hydrocarbons in phosphine resistance. Direct immersion solid-phase microextraction followed by gas chromatography-mass spectrometry (GC-MS) was applied to extract and analyze the cuticular hydrocarbons. The results showed significant differences between the resistant and susceptible strains regarding the cuticular hydrocarbons that were investigated. The resistant insects of both species contained higher amounts than the susceptible insects for the majority of the hydrocarbons, sixteen from cuticular extraction and nineteen from the homogenized body extraction for T. castaneum and eighteen from cuticular extraction and twenty-one from the homogenized body extraction for R. dominica. 3-methylnonacosane and 2-methylheptacosane had the highest significant difference between the susceptible and resistant strains of T. castaneum from the cuticle and the homogenized body, respectively. Unknown5 from the cuticle and 3-methylhentriacontane from the homogenized body recorded the highest significant differences in R. dominica. The higher hydrocarbon content is a key factor in eliminating phosphine from entering resistant insect bodies, acting as a barrier between insects and the surrounding phosphine environment.


Assuntos
Alcanos/isolamento & purificação , Besouros/efeitos dos fármacos , Resistência a Inseticidas/fisiologia , Inseticidas/farmacologia , Fosfinas/farmacologia , Tribolium/efeitos dos fármacos , Alcanos/química , Alcanos/classificação , Animais , Besouros/química , Besouros/fisiologia , Misturas Complexas/química , Grão Comestível/parasitologia , Cromatografia Gasosa-Espectrometria de Massas , Tegumento Comum/fisiologia , Microextração em Fase Sólida , Tribolium/química , Tribolium/fisiologia , Triticum/parasitologia
13.
Insect Biochem Mol Biol ; 122: 103377, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32302638

RESUMO

The potential utility of RNA interference (RNAi) to control insect pests and viral infections depends largely on the target organism's ability to systemically spread the RNAi response. The efficacy of systemic RNAi varies among insects, though it has been shown to be high in the red flour beetle, Tribolium castaneum. We identified an extracellular RNAi signal that is present in the culture medium of T. castaneum (TcA) cells after treatment with long dsRNA specific for a luciferase reporter gene. Luciferase-specific siRNAs were detected in extracellular vesicles (EVs) that were purified from the culture medium of these dsRNA-treated cells. Furthermore, by measuring the silencing of luciferase expression, we showed that these siRNA-containing EVs can act as an RNAi signal for recipient TcA cells. We have therefore shown that a systemic RNAi response upon dsRNA treatment can be effectively spread through EVs.


Assuntos
Vesículas Extracelulares/metabolismo , Interferência de RNA , Tribolium/fisiologia , Animais , Linhagem Celular , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/metabolismo
14.
Bull Entomol Res ; 110(4): 550-557, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32096756

RESUMO

Tribolium castaneum is one of the most economically important insects that damages stored products. The effects of several infested or uninfested raw feed materials (wheat bran, coarse wheat meal, corn feed flour), feed products (compound feed for pigs and for laying hens) and flour mixed with brewer's yeast on the food-searching behaviour of T. castaneum adults were studied in a total of 48 combinations. Preference and olfactometer tests revealed that all the tested uninfested and intraspecific infested substrates were significantly more attractive to T. castaneum than the control (represented by part of an arena or olfactometer arm without substrate). We determined that all infested substrates were 2-9 times more attractive than uninfested in the preference test, while in the olfactometer test, they were 3-8 times more attractive. In comparing the attractiveness of the infested and uninfested substrates, in both tests wheat bran was found to be the most attractive substrate to T. castaneum adults and coarse wheat meal the least. The results of the present study contribute to our knowledge of how raw feed materials and products influence the behaviour of T. castaneum and their susceptibility to infestation, and indicate the possible utilization of wheat bran in monitoring processes of T. castaneum in pest management programmes.


Assuntos
Comportamento Apetitivo , Odorantes , Tribolium/fisiologia , Ração Animal , Animais , Sinais (Psicologia) , Saccharomyces cerevisiae , Triticum , Zea mays
15.
Sci Rep ; 10(1): 1090, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974446

RESUMO

Several studies showed adult persisting neurogenesis in insects, including the red flour beetle Tribolium castaneum, while it is absent in honeybees, carpenter ants, and vinegar flies. In our study, we focus on cell proliferation in the adult mushroom bodies of T. castaneum. We reliably labelled the progenies of the adult persisting mushroom body neuroblasts and determined the proliferation rate under several olfactory conditions within the first week after adult eclosion. We found at least two phases of Kenyon cell proliferation in the early adult beetle. Our results suggest that the generation of Kenyon cells during the first three days after adult eclosion is mainly genetically predetermined and a continuation of the developmental processes (nature), whereas from day four on proliferation seems to be mainly dependent on the odour environment (nurture). Considering that the mushroom bodies are linked to learning and memory, neurogenesis in the mushroom bodies is part of the remodelling of neuronal circuits leading to the adaption to the environment and optimization of behaviour.


Assuntos
Corpos Pedunculados/crescimento & desenvolvimento , Neurogênese , Tribolium/fisiologia , Animais , Feminino , Masculino , Memória , Corpos Pedunculados/fisiologia , Odorantes/análise , Olfato , Tribolium/crescimento & desenvolvimento
16.
Ecotoxicol Environ Saf ; 189: 109988, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31767459

RESUMO

Tribolium casteneum is a major stored grains pest causing huge loss by secreting toxic quinones' which make the grains unfit for human consumption. Increasing concern about the fast-growing resistance in T. casteneum against fumigants has evoked more intense research worldwide. Therefore, finding an eco-friendly alternative for the management of the pest is of great importance. In this study, the insecticidal activity of the essential oils (EOs) of Artemisia annua is evaluated. Chemical composition of the EOs eluted with methanol and petroleum ether was analysed through Gas chromatography-mass spectrometry (GC-MS). The result has reported a total of 13 & 16 compounds in the methanol and petroleum ether EOs respectively. In contact toxicity studies, adults were found more susceptible to the petroleum ether EOs (LD50 = 0.43 mg adult-1) than the methanolic EOs (LD50 = 1.87 mg adult-1). Petroleum ether EOs was also superior in fumigant assays against both the adults (0.81 mg L air-1) and larvae (0.65 mg L air-1). Moreover, the same was also recorded as a strong repellent. The bio-molecular studies conducted to gain an insight into the extent of metabolic disturbances inflicted in the treatment sets has shown a significant increase in Lipid peroxidase and decrease (p˂0.01) in protein, Acetylcholinesterase, Glutathione S Transferees, Reduced Glutathione level. This indicates the major signs of oxidative stress in the treatment sets. The Results ascertain the knowledge to develop natural insecticides from Artemisia annua using a potential solvent to be used in the future as an efficient management tool against T. casteneum.


Assuntos
Artemisia annua/química , Controle de Insetos/métodos , Inseticidas/farmacologia , Óleos Voláteis/farmacologia , Tribolium/fisiologia , Animais , Repelentes de Insetos/química , Repelentes de Insetos/isolamento & purificação , Repelentes de Insetos/farmacologia , Inseticidas/química , Inseticidas/isolamento & purificação , Larva/metabolismo , Larva/fisiologia , Dose Letal Mediana , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Estresse Oxidativo/efeitos dos fármacos , Tribolium/metabolismo
17.
J Sci Food Agric ; 100(4): 1541-1546, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31769025

RESUMO

BACKGROUND: Citrus sinensis, Allium sativum, Ocimum basilicum, Mentha spicata, Curcuma longa, Carica papaya, Andrographis paniculata, Azadirachta indica, Cymbopogon citratus and Acorus calamus were compared in the form of extracts of chloroform, hexane and aqueous media for their effectiveness in repelling Tribolium castaneum. Filter paper of 9 cm in diameter was cut into halves. Using a micro-pipette, each extract was applied to one half of the filter paper. The volume applied was kept constant at 0.6 mL per 30 cm2 . The filter paper was dried and reattached leaving a 0.5 cm gap between, in a Petri-plate. Ten adults of T. castaneum were introduced and the repellency was observed after 30, 60 and 180 min. RESULTS: The aqueous extract of C. papaya exhibited the highest repellency (82-97%) followed by that of garlic bulbs (aqueous extract) with 86.67% repellency. Further, gunny bags were sprayed separately using bottle sprayers with the two most effective extracts at a constant volume of 42 mL per 575 cm2 . These treated gunny bags were compared with malathion-treated gunny bags in the insect management unit. The observations were taken after 2, 8 and 24 h. Papaya leaf extract-treated gunny bags showed relative repellent activity similar to that of malathion-treated gunny bags after 24 h of treatment. Thus, gas chromatography-mass spectrometry analysis of aqueous extract of papaya leaves was performed. CONCLUSIONS: It can be concluded that extract of papaya leaves containing 2-methoxy-4-vinylphenol (8.47% peak area) can be used as a repellent biopesticide. © 2019 Society of Chemical Industry.


Assuntos
Repelentes de Insetos/farmacologia , Extratos Vegetais/farmacologia , Tribolium/efeitos dos fármacos , Andrographis/química , Animais , Azadirachta/química , Carica/química , Curcuma/química , Cymbopogon/química , Alho/química , Repelentes de Insetos/química , Repelentes de Insetos/isolamento & purificação , Mentha spicata/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Tribolium/fisiologia
18.
Sci Rep ; 9(1): 11544, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395934

RESUMO

Confused flour beetles are serious pests of stored grain products, and therefore, it is important to efficiently monitor and control their populations. Aggregation pheromones are commercially used for monitoring this beetle but their efficacy has been questioned and they may be inadequate for practical use. Food attractants as well as pheromones are commonly used for monitoring stored-product insects. However, food attractants may not be effective in the case of food handling facilities, which are already filled with food odours. The ancestors of flour beetles may have been associated with dead or decomposing woody vegetation, so we investigated the attractiveness of several wood odours to beetles using a pitfall olfactometer. The beetles were strongly attracted to all wood odours tested: Castanea crenata, Magnolia obovata, Paulownia tomentosa, Prunus jamasakura, and Zelkova serrata. The attractiveness of these wood odours was also stronger than that of the odours of the usual food of these beetles. Supercritical CO2 extracts of these species of wood were also attractive to the beetles. The Z. serrata extract was the most attractive among these extracts, and was further analysed by gas chromatography mass spectrometry. One major compound, (-)-mellein, was detected in the extract. Synthetic (±)-mellein attracted the beetles.


Assuntos
Comportamento Alimentar/fisiologia , Feromônios/química , Tribolium/fisiologia , Madeira/química , Animais , Grão Comestível/química , Cromatografia Gasosa-Espectrometria de Massas , Insetos , Odorantes/análise , Feromônios/metabolismo , Feromônios/farmacologia , Tribolium/efeitos dos fármacos
19.
Behav Genet ; 49(5): 478-483, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31227945

RESUMO

Tonic immobility (TI) is an effective anti-predator strategy. However, long immobility status on the ground increases the risk of being eaten by predators, and thus insects must rouse themselves when appropriate stimulation is provided. Here, the strength of vibration causing arousal from the state of TI was examined in strains artificially selected for longer duration of TI (L-strains: long sleeper) in a beetle. We provided different strengths of vibration stimuli to the long sleepers in Tribolium castaneum. Although immobilized beetles were never awakened by the stimuli from 0.01 to 0.12 mm in amplitude, almost of the beetles were aroused from immobilized status by the stimulus at 0.21 mm. There was a difference in sensitivity of individuals when the stimuli of 0.14 mm and 0.18 mm were provided. F2 individuals were also bred by crossing experiments of the strains selected for shorter and longer duration of TI. The arousal sensitivity to vibration was well separated in the F2 individuals. A positive relationship was observed between the duration of TI and the vibration amplitude, suggesting that immobilized beetles are difficult to arouse from a deep sleep, while light sleepers are easily aroused by even small vibrations. The results indicate a genetic basis for sensitivity to arousal from TI.


Assuntos
Nível de Alerta/genética , Resposta de Imobilidade Tônica/fisiologia , Tribolium/fisiologia , Animais , Nível de Alerta/fisiologia , Besouros/fisiologia , Feminino , Masculino , Sono/genética , Sono/fisiologia , Vibração
20.
Environ Sci Pollut Res Int ; 26(14): 14200-14213, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30864036

RESUMO

Resistance to grain protectants in Tribolium castaneum (Herbst) is a serious threat to international grain trade. Frequent and overdose application of chemical insecticides is becoming a serious health hazard and cause environmental pollution. Resistance management approaches by using various synergists along with novel compounds has become more imperative to increase efficacy of environmentally safe insecticides. We have evaluated piperonyl butoxide (PBO) and emamectin benzoate mixtures for management of resistant field populations of T. castaneum. The collected strains had demonstrated 50 to 200% resistance already developed against emamectin benzoate as compared with deltamethrin susceptible reference strain. The inclusion of PBO along with emamectin significantly reduced this resistance by at least 28% and the LC50 were lowered from 5.12 to 1.9 µg/ml with the highest synergism ration of 2.7 in resistant strain. Enzymatic assays clearly demonstrated that the specific activities of catalase and acetylcholinesterases were significantly decreased at an average of 80% and 60%, respectively, when PBO was included as a synergist at 1:2 ratio with emamectin benzoate. The results highlight the mechanism that renders the field population resistant to emamectin benzoate and suggests the synergistic role of piperonyl butoxide as a potent additive in grain protectants for resistance management.


Assuntos
Inseticidas/farmacologia , Ivermectina/análogos & derivados , Butóxido de Piperonila/farmacologia , Tribolium/fisiologia , Animais , Besouros/efeitos dos fármacos , Dissacarídeos , Resistência a Inseticidas , Ivermectina/farmacologia , Nitrilas , Piretrinas
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