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1.
J Insect Sci ; 20(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32104893

RESUMO

Different densities prerelease packing and times of lethargy in the fruit fly parasitoids Diachasmimorpha longicaudata (Ashmead) were evaluated in order to standardize the process of chilled insect technique for this species. Adults were kept at densities of 0.048, 0.072, 0.096, 0.120, and 0.144 parasitoids/cm2 before release in a México tower, where thermal lethargy was induced at a temperature of 2 ± 2°C for 45 min. Samples of parasitoids were collected to evaluate mortality, survival, fecundity, and flight capacity. All densities showed a similar mortality, both for males (ca. >10%) and females (ca. <7). There was no effect of density on survival and flight capacity in both sexes. On the other hand, fecundity increased with density, 1.66 sons/♀/day, similar to the control. We conclude that a density of 30,000 pupae per cage (0.144 parasitoids/cm2) is adequate for the massive prerelease packaging of the parasitoid D. longicaudata. Regarding the thermal lethargy period, 180 min under 2 ± 2°C conditions, considered as time for management, does not affect the survival, fecundity, and flight capacity of adults. The results obtained are of great utility to establish prerelease packaging parameters for D. longicaudata used in the biological control of Tephritidae fruit fly populations.


Assuntos
Temperatura Baixa , Controle Biológico de Vetores/métodos , Vespas/fisiologia , Animais , Feminino , Fertilidade/fisiologia , Voo Animal/fisiologia , Masculino , Tephritidae/parasitologia
2.
Arch Insect Biochem Physiol ; 103(2): e21635, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31625210

RESUMO

Among insects, lifespans vary over a broad range, from the short-lived mayflies to the 17-year periodical cicadas. Generally, lifespans are determined by a phase in life, the reproductive lifespan, which varies among species. Numerous pathways, such as the insulin/insulin-like growth factor signaling pathway, the target of rapamycin pathway and the mitogen-activated protein kinase/extracellular signal-regulated kinases pathways, influence aging and lifespan. Components of these pathways were identified as lifespan-related genes, including genes mediating growth, metabolism, development, resistance, and other processes. Many age-related genes have been discovered in fruit flies, honeybees, and ants among other insect species. Studies of insect aging and longevity can help understand insect biology and develop new pest management technologies. In this paper, we interrogated the new Pteromalus puparum genome, from which we predicted 133 putative lifespan-related genes based on their homology with known lifespan-related genes of Drosophila melanogaster. These genes function in five signaling pathways and three physiological processes. The conserved domain structures of these genes were predicted and their expression patterns were analyzed. Amino acid sequence alignments and domain structure analysis indicate that most components remain conserved across at least six insect orders. The data in this paper will facilitate future work on parasitoid lifespans, which may have economic value in biocontrol programs.


Assuntos
Genoma de Inseto , Longevidade/genética , Transdução de Sinais , Transcriptoma , Vespas/fisiologia , Animais , Vespas/genética
3.
Insect Biochem Mol Biol ; 117: 103286, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31760134

RESUMO

Chouioia cunea (Yang) is a pupal parasitoid wasp and this species is able to seek host insects depending on its olfactory system. However, the molecular mechanism of the olfactory system in the C. cunea is still limited. To identify putative semiochemicals bound to CcOBP2, a protein specifically expressed in antennae, 14 compounds from the pupae of H. cunea and 11 common volatile compounds from plants were selected for competitive fluorescence binding assay. The result of the binding assay showed that five compounds were able to bind toCcOBP2. The electroantennogram (EAG) demonstrated that the antennae had a significant response to the 3-Carene, a bicyclic monoterpene, and C. cunea could be obviously attracted by this compound. The behavioral response to 3- carene was dramatically weakened when CcOBP2 was specifically knocked down. The molecular docking result indicated that several amino acids especially Ile-81, Val-122, Phe-123 of CcOBP2 were responsible for binding to 3-Carene. Furthermore, there was a repellent effect on the host H. cunea with the treatment of the 3-Carene. This study illustrated that CcOBP2 might be a crucial protein involved in the olfactory signaling pathway and the 3-Carene, secreted from plants, could probably have a potential role in repelling pests as well as attracting natural enemies.


Assuntos
/metabolismo , Proteínas de Insetos/metabolismo , Mariposas/parasitologia , Percepção Olfatória , Receptores Odorantes/metabolismo , Vespas/fisiologia , Animais , Antenas de Artrópodes/fisiologia , Quimiotaxia , Regulação da Expressão Gênica , Mariposas/metabolismo , Pupa/metabolismo , Pupa/parasitologia
4.
Arch Insect Biochem Physiol ; 103(2): e21629, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31599031

RESUMO

Parasitoids serve as effective biocontrol agents for agricultural pests. However, they face constant challenges from host immune defense and numerous pathogens and must develop potent immune defense against these threats. Despite the recent advances in innate immunity, little is known about the immunological mechanisms of parasitoids. Here, we identified and characterized potential immune-related genes of the endoparasitoid, Pteromalus puparum, which act in regulating populations of some members of the Pieridae. We identified 216 immune-related genes based on interrogating the P. puparum genome and transcriptome databases. We categorized the cognate gene products into recognition molecules, signal moieties and effector proteins operating in four pathways, Toll, IMD, JAK/STAT, and JNK. Comparative analyses of immune-related genes from seven insect species indicate that recognition molecules and effector proteins are more expanded and diversified than signaling genes in these signal pathways. There are common 1:1 orthologs between the endoparasitoid P. puparum and its relative, the ectoparasitoid Nasonia vitripennis. The developmental expression profiles of immune genes randomly selected from the transcriptome analysis were verified by a quantitative polymerase chain reaction. Our work provides comprehensive analyses of P. puparum immune genes, some of which may be exploited in advancing parasitoid-based biocontrol technologies.


Assuntos
Proteínas de Transporte/genética , Imunidade Inata/genética , Proteínas de Insetos/genética , Transdução de Sinais/imunologia , Vespas/genética , Sequência de Aminoácidos , Animais , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Embrião não Mamífero/química , Embrião não Mamífero/metabolismo , Feminino , Perfilação da Expressão Gênica , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Masculino , Filogenia , Pupa/genética , Pupa/metabolismo , Alinhamento de Sequência , Vespas/crescimento & desenvolvimento , Vespas/metabolismo , Vespas/fisiologia
5.
Bull Entomol Res ; 110(1): 34-43, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31190653

RESUMO

Gall formation is associated with multiple changes in plant cells, which still requires a better understanding. In this study, galls caused by sexual generation (♀♂) of Neuroterus quercusbaccarum (L.) (Hymenoptera: Cynipidae) on pedunculate oak trees (Quercus robur L.) were used as a model. Cytoplasmic membrane condition, concentration of hydrogen peroxide (H2O2), the activity of antioxidant enzymes and amino acid decarboxylase as well as chlorophyll fluorescence parameters were determined. Changes in physiological and biochemical parameters were analyzed in foliar tissues with galls and gall tissues themselves and compared to control. The presence of galls on oak leaves caused an increase of lipid peroxidation level. A significant decline in H2O2 and TBARS content with the reduction of guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) activity were observed in gall tissues. The activity amino acid decarboxylase, i.e., LDC, ODC and TyDC varied between samples, which may affect the content of amino acids. The presence of N. quercusbaccarum galls caused an insignificant increase of the chlorophylls, carotenoids and anthocyanin contents, while the content of pigments and their ratios in gall tissues was extremely low. Moreover, photosynthetic parameters (F0, Fm, Fv/Fm, Y, qP) were significantly decreased. Data generated in this study indicate that the development of N. quercusbaccarum galls on pedunculate oak leaves has a negative effect on host plant related to the disruption of cell membrane integrity, disturbance of photosynthesis and reduction of the antioxidant potential of the host plant.


Assuntos
Interações Hospedeiro-Parasita , Folhas de Planta/parasitologia , Tumores de Planta , Quercus/parasitologia , Vespas/fisiologia , Animais , Membrana Celular/fisiologia , Feminino , Glutationa Peroxidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Masculino , Estresse Oxidativo , Fotossíntese , Pigmentação , Folhas de Planta/fisiologia , Quercus/fisiologia
6.
Insect Sci ; 27(1): 122-132, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29659142

RESUMO

Although the Neotropical territorially dominant arboreal ant Azteca chartifex Forel is very aggressive towards any intruder, its populous colonies tolerate the close presence of the fierce polistine wasp Polybia rejecta (F.). In French Guiana, 83.33% of the 48 P. rejecta nests recorded were found side by side with those of A. chartifex. This nesting association results in mutual protection from predators (i.e., the wasps protected from army ants; the ants protected from birds). We conducted field studies, laboratory-based behavioral experiments and chemical analyses to elucidate the mechanisms allowing the persistence of this association. Due to differences in the cuticular profiles of the two species, we eliminated the possibility of chemical mimicry. Also, analyses of the carton nests did not reveal traces of marking on the envelopes. Because ant forager flows were not perturbed by extracts from the wasps' Dufour's and venom glands, we rejected any hypothetical action of repulsive chemicals. Nevertheless, we noted that the wasps "scraped" the surface of the upper part of their nest envelope using their mandibles, likely removing the ants' scent trails, and an experiment showed that ant foragers were perturbed by the removal of their scent trails. This leads us to use the term "erasure hypothesis." Thus, this nesting association persists thanks to a relative tolerance by the ants towards wasp presence and the behavior of the wasps that allows them to "contain" their associated ants through the elimination of their scent trails, direct attacks, "wing-buzzing" behavior and ejecting the ants.


Assuntos
Formigas/fisiologia , Comportamento de Nidação , Vespas/fisiologia , Agressão , Animais , Guiana Francesa , Territorialidade , Árvores
7.
Insect Sci ; 27(1): 170-184, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29938899

RESUMO

Elevated concentrations of atmospheric CO2 can alter plant secondary metabolites, which play important roles in the interactions among plants, herbivorous insects and natural enemies. However, few studies have examined the cascading effects of host plant secondary metabolites on tri-trophic interactions under elevated CO2 (eCO2 ). In this study, we determined the effects of eCO2 on the growth and foliar phenolics of Medicago truncatula and the cascading effects on two color genotypes of Acyrthosiphon pisum (pink vs. green) and their parasitoid Aphidius avenae in the field open-top chambers. Our results showed that eCO2 increased photosynthetic rate, nodule number, yield and the total phenolic content of M. truncatula. eCO2 had contrasting effects on two genotypes of A. pisum; the green genotype demonstrated increased population abundance, fecundity, growth and feeding efficiency, while the pink genotype showed decreased fitness and these were closely associated with the foliar genstein content. Furthermore, eCO2 decreased the parasitic rate of A. avenae independent of aphid genotypes. eCO2 prolonged the emergence time and reduced the emergence rate and percentage of females when associated with the green genotype, but little difference, except for increased percentage of females, was observed in A. avenae under eCO2 when associated with the pink genotype, indicating that parasitoids can perceive and discriminate the qualities of aphid hosts. We concluded that eCO2 altered plant phenolics and thus the performance of aphids and parasitoids. Our results indicate that plant phenolics vary by different abiotic and biotic stimuli and could potentially deliver the cascading effects of eCO2 to the higher trophic levels. Our results also suggest that the green genotype is expected to perform better in future eCO2 because of decreased plant resistance after its infestation and decreased parasitic rate.


Assuntos
Afídeos/fisiologia , Afídeos/parasitologia , Dióxido de Carbono/metabolismo , Medicago truncatula/química , Fenóis/metabolismo , Vespas/fisiologia , Animais , Afídeos/crescimento & desenvolvimento , Herbivoria , Interações Hospedeiro-Parasita , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia , Ninfa/fisiologia , Vespas/crescimento & desenvolvimento
8.
J Chem Ecol ; 45(11-12): 982-992, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31784860

RESUMO

Plants have evolved intricate defence strategies against herbivore attack which can include activation of defence in response to stress-related volatile organic compounds (VOCs) emitted by neighbouring plants. VOCs released by intact molasses grass (Melinis minutiflora), have been shown to repel stemborer, Chilo partellus (Swinhoe), from maize and enhance parasitism by Cotesia sesamiae (Cameron). In this study, we tested whether the molasses grass VOCs have a role in plant-plant communication by exposing different maize cultivars to molasses grass for a 3-week induction period and then observing insect responses to the exposed plants. In bioassays, C. partellus preferred non-exposed maize landrace plants for egg deposition to those exposed to molasses grass. Conversely, C. sesamiae parasitoid wasps preferred volatiles from molasses grass exposed maize landraces compared to volatiles from unexposed control plants. Interestingly, the molasses grass induced defence responses were not observed on hybrid maize varieties tested, suggesting that the effect was not simply due to absorption and re-emission of VOCs. Chemical and electrophysiological analyses revealed strong induction of bioactive compounds such as (R)-linalool, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene from maize landraces exposed to molasses grass volatiles. Our results suggest that constitutively emitted molasses grass VOCs can induce direct and indirect defence responses in neighbouring maize landraces. Plants activating defences by VOC exposure alone could realize enhanced levels of resistance and fitness compared to those that launch defence responses upon herbivore attack. Opportunities for exploiting plant-plant signalling to develop ecologically sustainable crop protection strategies against devastating insect pests such as stemborer C. partellus are discussed.


Assuntos
Compostos Orgânicos Voláteis/química , Zea mays/metabolismo , /química , Animais , Produtos Agrícolas , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Herbivoria , Interações Hospedeiro-Parasita , Melaço , Mariposas/parasitologia , Oviposição/efeitos dos fármacos , Compostos Orgânicos Voláteis/metabolismo , Vespas/fisiologia , Zea mays/parasitologia
9.
J Chem Ecol ; 45(11-12): 972-981, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31713110

RESUMO

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


Assuntos
Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Tabaco/parasitologia , Vespas/fisiologia , Animais , Feminino , Glucose Desidrogenase/metabolismo , Glucose Oxidase/metabolismo , Interações Hospedeiro-Parasita , Larva/metabolismo , Lycopersicon esculentum/metabolismo , Oviposição/fisiologia , Parasitos , Doenças das Plantas/parasitologia , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Especificidade da Espécie , Tabaco/metabolismo
10.
DNA Cell Biol ; 38(12): 1512-1518, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31613654

RESUMO

The plasma levels of interleukin-8 (IL-8) and its receptors (CXCR1 and CXCR2) play a significant role in the development of systemic inflammatory response syndrome (SIRS), but it is not clear how these proteins are involved in wasp sting patients developing SIRS. To study potential genetic factors predisposing to the risk of SIRS caused by wasp sting injury, we determined the plasma levels of IL-8 and its receptors among SIRS patients with wasp sting injury and investigated the association of single-nucleotide polymorphisms of these genes with SIRS. A total of 225 patients were divided into the SIRS group (n = 62) and non-SIRS group (control, n = 163), and we associated polymorphisms in IL-8 [rs4073 (-251T>A), rs2227532 (-845C>T), rs2227307 (+396G>T), rs2227306 (+781T>C), CXCR1 rs2234671 (+860C>G), CXCR2 [rs2230054 (+811T>C), rs57929613 (+1235C>T), and rs60626131 (+1440A>G)] with SIRS with a linear additive model. In terms of protein expression, the IL-8, CXCR1, and CXCR2 plasma levels were significantly higher in the SIRS group than in the control group (p < 0.001). Significantly higher frequencies were observed for the IL-8 - 251T allele (AT+TT), CXCR2 + 811T allele (CT+TT), and +1235C allele (TC+CC) in the SIRS group, when compared with the control group, with odds ratio (OR) = 3.971 (95% confidence interval [CI], 1.618-9.734), p = 0.003; OR = 4.223 (95% CI, 1.863-9.571), p = 0.001; and OR = 4.012 (95% CI, 1.773-9.079), p = 0.001; respectively. In addition, SIRS is more likely to occur in males, patients with number of wasp stings ≥10 stings, and stings in the limbs. The current study suggests that the IL-8 - 251T allele (AT+TT) and IL-8 receptor CXCR2 + 811C allele (CT+TT) and +1235T allele (TC+CC) could be risk factors among SIRS patients with wasp sting injury.


Assuntos
Mordeduras e Picadas de Insetos/fisiopatologia , Interleucina-8/genética , Receptores de Interleucina-8A/genética , Receptores de Interleucina-8B/genética , Síndrome de Resposta Inflamatória Sistêmica/epidemiologia , Síndrome de Resposta Inflamatória Sistêmica/genética , Vespas/fisiologia , Adolescente , Adulto , Idoso , Animais , Estudos de Casos e Controles , China/epidemiologia , Feminino , Humanos , Incidência , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Curva ROC , Receptores de Interleucina-8A/sangue , Receptores de Interleucina-8B/sangue , Síndrome de Resposta Inflamatória Sistêmica/patologia , Adulto Jovem
11.
Naturwissenschaften ; 106(9-10): 52, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31482235

RESUMO

Parasitoid researchers have generally thought that the body size of the mother parasitoid does not affect the fitness performance of the progeny during the immature stage, as long as the progeny develop in the same environment. We reveal for the first time that this is not true for the parasitoid Echthrodelphax fairchildii (Hymenoptera: Dryinidae), which is parasitic on planthoppers. Large females ensured an increased survival rate for their progeny during the immature stage and a large body size at adult emergence. Maternal body size differentially affected the body sizes and survival rates of male and female progeny. Small females did not produce female progeny, and the survival rate of the female progeny increased more steeply with increasing maternal body size than that of the male progeny. Meanwhile, the body size of male progeny increased more steeply with increasing maternal body size. The influence of maternal body size on progeny survival to adult emergence has never been reported in insects before. In addition, large females were more likely to lay female eggs, suggesting that females control the sex ratio of progeny in response to their own body size.


Assuntos
Tamanho Corporal/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Vespas/anatomia & histologia , Vespas/fisiologia , Animais , Feminino , Larva/anatomia & histologia , Larva/fisiologia , Masculino , Oviposição/fisiologia , Taxa de Sobrevida
12.
Arthropod Struct Dev ; 52: 100882, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31472312

RESUMO

Digger wasps of the family Crabronidae (Insecta: Hymenoptera) are generally known to use their sting to paralyze or kill a prey. However, only a few species of digger wasps transport their prey to the nest impaled on the sting. How sting morphology correlates with this peculiar type of prey carriage is still unclear. We examined the sting morphology of two phylogenetically closely-related species of digger wasps of similar size, which hunt for similar preys but use different types of prey transportation. Data from light microscopy (LM), scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were analyzed to find possible correlations between shape, material composition, and function of the stings. The similarity of the material composition in the stings of the two species suggests that the material of stings does not play a dominant role in their functional differences. On the contrary, differences in the curvature and surface sculpture of sting elements likely result in different stress distributions under mechanical loading.


Assuntos
Comportamento de Nidação , Vespas/anatomia & histologia , Animais , Fenômenos Biomecânicos , Feminino , Microscopia , Microscopia Confocal , Microscopia Eletrônica de Varredura , Especificidade da Espécie , Vespas/fisiologia , Vespas/ultraestrutura
13.
J Insect Sci ; 19(4)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31393980

RESUMO

Trissolcus japonicus (Ashmead), an Asian parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), was first detected in North America in 2014. Although testing in quarantine facilities as a candidate for classical biological control is ongoing, adventive populations have appeared in multiple sites in the United States, Canada, and Europe. Extensive laboratory testing of T. japonicus against other North American pentatomids and H. halys has revealed a higher rate of parasitism of H. halys, but not complete host specificity. However, laboratory tests are necessarily artificial, in which many host finding and acceptance cues may be circumvented. We offered sentinel egg masses of three native pentatomid (Hemiptera: Pentatomidae) pest species (Chinavia hilaris (Say), Euschistus conspersus Uhler, and Chlorochroa ligata (Say)) in a field paired-host assay in an area with a well-established adventive population of T. japonicus near Vancouver, WA. Overall, 67% of the H. halys egg masses were parasitized by T. japonicus during the 2-yr study. Despite the 'worst case' scenario for a field test (close proximity of the paired egg masses), the rate of parasitism (% eggs producing adult wasps) on all three native species was significantly less (0.4-8%) than that on H. halys eggs (77%). The levels of successful parasitism of T. japonicus of the three species are C. hilaris > E. conspersus > C. ligata. The potential impact of T. japonicus on these pentatomids is probably minimal.


Assuntos
Heterópteros/parasitologia , Interações Hospedeiro-Parasita , Vespas/fisiologia , Animais , Feminino , Heterópteros/crescimento & desenvolvimento , Espécies Introduzidas , Ninfa/parasitologia , Washington
14.
J Chem Ecol ; 45(8): 715-724, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31385154

RESUMO

Plants emit a specific blend of volatiles in response to herbivory and these volatiles, which often attract predators and parasitoids function as an indirect plant defense. The impact of plant volatiles in shaping herbivore defenses is unclear. Here, we report that specific plant volatiles induce immune responses in the polyphagous herbivore, Spodoptera litura. We characterized the hemocyte profile and established their functional significance with respect to ontogeny and exposure to specific plant volatiles. Fifth instar larvae showed the highest number and hemocytes diversity. We characterized seven different types of hemocytes, of which granulocytes performed phagocytosis, oenocytoids showed melanization activity, and plasmatocytes along with granulocytes and oenocytoids were found to be involved in encapsulation. Among the six volatiles tested, exposure to (E)-ß-ocimene caused the highest increase in total hemocytes number (THC) followed by linalool and (Z)-3-hexenyl acetate exposure. Although THC did not differ between these three volatile treatments, circulating hemocytes diversity varied significantly. (E)-ß-ocimene exposure showed higher number of plasmatocytes and phenol oxidase activity. The interaction of the parasitic wasp Bracon brevicornis with (E)-ß-ocimene exposed larvae was poor in terms of delayed paralysis and lower egg deposition. In choice assays, the wasp showed clear preference towards control larvae indicating (E)-ß-ocimene treatment renders the host unattractive. Hemocyte profiles post-parasitoid exposure and (E)-ß-ocimene treatment were similar indicating cue-based priming. When challenged with Bacillus thuringiensis, linalool exposure resulted in the highest survival as compared to other volatiles. Our results show that specific HIPVs can modulate cellular immunity of S. litura, revealing a new role for HIPVs in tri-trophic interactions.


Assuntos
Compostos Orgânicos Voláteis/farmacologia , Vespas/fisiologia , Alcenos/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Hemócitos/citologia , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Herbivoria , Interações Hospedeiro-Parasita , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/metabolismo , Larva/fisiologia , Monofenol Mono-Oxigenase/metabolismo , Monoterpenos/farmacologia , Oviposição/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Plantas/química , Plantas/metabolismo , Plantas/parasitologia , Compostos Orgânicos Voláteis/química , Vespas/imunologia
15.
J Therm Biol ; 84: 214-220, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466756

RESUMO

Social insects depend on their nests for protection against predation and abiotic threats. Accordingly, the chemical compounds present in the material wasps use to build their nests can both facilitate communication and repel predators. It is herein hypothesized that different wasp species build their nests with different structure and substrate materials and that such materials consist of chemical compounds related to unique wasp behavior and outside temperature variation. To test this hypothesis, nests were collected from three species of social wasps, the samples of which were subjected to temperature variation under laboratory conditions. The compounds present in the substrate were analyzed by gas chromatography coupled to mass spectrometry. Chemical compounds identified in the nest material of the three species responded differently to temperature variation. Chemical compounds from Polybia nests were altered significantly when subjected to temperature variation, whereas the nests of Polistes versicolor did not significantly change in relation to the control. The differences found between Polistes and Polybia nests may be related to genetic factors, but also to the type of nest they construct. It is possible that divergent evolutionary strategies for maintaining colony temperature, as a function of the chemical composition of the nests, may have appeared between wasps that have open and closed nests. In relatively small colonies, nest substrate is more resistant to temperature variation because it is composed of a greater diversity of elements and thus capable of holding heavier, longer carbon chains. Our results suggest that chemical compounds in the nest material of the three wasp species analysed responded differently to fluctuating ambient temperatures and that such variation could result from the biochemical differences of unique wasp species or from thermoregulation strategies of colonies.


Assuntos
Regulação da Temperatura Corporal , Hidrocarbonetos/análise , Comportamento de Nidação , Vespas/fisiologia , Animais , Temperatura Ambiente
16.
J Insect Physiol ; 117: 103909, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31295454

RESUMO

In ectotherm species such as insects, thermal fluctuations represent a major environmental factor driving development, survival and reproduction of individuals. Reproductive traits are particularly sensitive to heat stress that can induce a permanent sterility, or at least hypofertility, of adult males. This study aims to compare physiological and biochemical responses associated to male performances to an exposure of 24 h to moderately high temperature (36 °C) among three inbred lines of N. vitripennis (AsymC, Cor, Oul). Cor males showed very specific metabolic adjustments compared to the two other lines. By contrast, Oul males showed stronger phenotypic adjustment of its life cycle, and produced metabolic water to compensate water loss by heat stress. Finally, AsymC males had probably more difficulties to acclimate at 36 °C, even for a short period, as their adult longevity was significantly reduced. Thus, the ability of developmental plasticity in N. vitripennis males exposed to heat stress appears to be dependent of their genotypes.


Assuntos
Resposta ao Choque Térmico , Traços de História de Vida , Vespas/fisiologia , Animais , Genótipo , Longevidade , Masculino , Pupa/crescimento & desenvolvimento , Contagem de Espermatozoides
18.
J Insect Sci ; 19(4)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31319420

RESUMO

Trichogramma spp., among the most common parasitoids used for augmentation biological control, often are mass-reared on eggs of the Mediterranean flour moth, Ephestia kuehniella (Zeller). To evaluate removal of nutritional components from the E. kuehniella larval diet and reduce production costs, colonies were maintained using one of three diets: a standard diet consisting of eight ingredients, a reduced diet containing whole wheat flour, glycerol, and Brewer's yeast, or a third minimal diet of only whole wheat flour. The standard diet sustained the fastest larval development, female pupae with the greatest mass, the highest level of adult emergence, and production of the most eggs per female. Eggs from moths reared as larvae on the standard or reduced diet had equivalent mass, length, and percent hatch. Females from larvae fed the minimal diet produced eggs with the least mass that were shorter and had the lowest percent hatch. Eggs from the three E. kuehniella colonies were exposed separately to Trichogramma brassicae Bezdenko females to determine their acceptance for oviposition. More of the eggs from the standard diet were parasitized by the females, eggs from the reduced and minimal diets being less acceptable. The percent emergence of the parasitoids was the same regardless of diet; however, the largest wasps emerged from the standard diet eggs and a greater proportion of them were females. Consequently, the standard E. kuehniella larval diet resulted in the highest rate of reproduction and robust eggs that produced superior T. brassicae wasps.


Assuntos
Dieta , Interações Hospedeiro-Parasita , Mariposas/parasitologia , Vespas/fisiologia , Animais , Feminino , Larva/crescimento & desenvolvimento , Mariposas/crescimento & desenvolvimento , Óvulo/parasitologia
19.
J Insect Physiol ; 117: 103910, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31279632

RESUMO

The lifetime reproductive success of a female parasitoid is limited by (1) host (or time) limitation - the number of hosts available for oviposition during its lifetime; and (2) egg limitation - its egg supply. Host limitation is expected to select for increased longevity and/or foraging efficiency, while increased fecundity is predicted to evolve under egg limitation. If the limiting factor varies, phenotypic plasticity in egg maturation schedules may be advantageous, i.e. adjusting investment in egg production to host availability. In the polyembryonic parasitoid Copidosoma koehleri, environmental conditions experienced during development indeed influence resource allocation to egg maturation. However, whether parasitoids' maternal environment also influences their daughters' egg production has hardly been studied. To address this knowledge gap, we tested whether exposure of C. koehleri females to previously parasitized hosts (signaling intraspecific exploitation competition and risk of host limitation) reduces their daughters' initial egg loads. We presented newly-emerged females with hosts that were either fresh or parasitized by conspecifics. The following day, we exposed both groups to additional fresh hosts, and reared out the daughters of these previously experienced, 24+ h old, individuals. The daughters' egg loads and body sizes were similar under both experimental conditions. Nevertheless, their egg loads were ~30% higher, and body sizes were ~10% lower, than in daughters of just-emerged parasitoids. We suggest that female experience or age, but not conditions associated with host exploitation, trigger maternal effects on the reproductive and developmental physiology of their daughters.


Assuntos
Interações Hospedeiro-Parasita , Óvulo/crescimento & desenvolvimento , Vespas/fisiologia , Animais , Feminino
20.
Sci Total Environ ; 689: 709-715, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31280152

RESUMO

Honeybees have an essential role in ecosystems pollinating wild flowers and cultivated crops, representing an important cultural and economic benefit for humans. Honeybee populations are decreasing over the last decade, due to multifactorial causes. The aim of this field study was to investigate the effects of the presence of the invasive species Vespa velutina, a bee predator, in oxidative stress parameters of honeybee workers. To achieve this objective, positive or negative apiaries for the presence of the V. velutina were selected. Five honeybees from six hives of each apiary were sampled in spring, summer and autumn, analysing a total of 233 samples. Analysis of mRNA expression of oxidative stress-related genes, catalase enzymatic activity and lipid peroxidation were performed. An increase in sod2, tpx3, trxR1, gtpx1, gstS1, coxI, cytC and if2mt genes expression, as well as a raise in catalase activity and lipid peroxidation were observed in V. velutina positive samples. Thus, here we present a new methodology to analyze the impact of the predation pressure of the invasive species V. velutina on honeybees under field conditions. In conclusion, the results obtained in this study indicate the negative impact of the presence of the yellow-legged hornet on honeybees' health and the activation of their antioxidant system to protect them against this biotic stressor. Moreover, the redox status they present could increase the susceptibility of honeybees, essential insects that currently receive many inputs of different stresses, to another stressor.


Assuntos
Abelhas/fisiologia , Estresse Oxidativo , Comportamento Predatório , Vespas/fisiologia , Animais , Cadeia Alimentar , Espécies Introduzidas
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