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1.
J Econ Entomol ; 116(4): 1261-1267, 2023 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-37229556

RESUMO

Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae) is a polyphagous insect pest attacking a wide variety of crops. In California's Central Valley, it is now the dominant leaffooted bug on almonds, pistachios, and pomegranates. Leptoglossus zonatus pest status depends largely on overwintering adult survival and reproductive potential, which determines its population size in spring and early summer when nut crops are particularly susceptible to bug damage. Here, we investigated the overwintering reproductive biology of L. zonatus in laboratory and field experiments to gain information about its ovary development, time of mating, and the impact of low temperatures on egg hatch. With dissections of laboratory-reared L. zonatus, we established a baseline for ovarian development and determined that the size of the spermathecal reservoir is larger in mated than in unmated females. Dissections and behavioral experiments of field-collected material provided evidence of mating events before dispersal from overwintering sites. Laboratory trials showed that temperature significantly impacted L. zonatus egg hatch. Leptoglossus zonatus reproductive biology presented provides valuable information on its population dynamics and dispersal from overwintering sites, and will contribute to the development of monitoring and management tools.


Assuntos
Heterópteros , Ovário , Oviposição , Animais , Feminino , California , Heterópteros/crescimento & desenvolvimento , Ovário/crescimento & desenvolvimento , Comportamento Sexual Animal , Estações do Ano , Temperatura Baixa
2.
J Insect Sci ; 22(4)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35780387

RESUMO

When quinoa, Chenopodium quinoa Willd., is cultivated in South America outside of its Andean origin, the heteropterans Liorhyssus hyalinus (Fabricius) and Nysius simulans Stål may emerge as important pests. Here we studied the development and reproduction of both species at different constant temperatures in the laboratory. Egg and nymphal development were investigated at 18, 22, 26, 30, 34, and 36°C. For both species, egg incubation time significantly decreased as the temperature increased. Nymphs did not successfully develop at 18°C and the total nymphal time significantly decreased as the temperature increased from 22 to 36°C. Based on a linear day-degree (DD) model, the lower developmental threshold (LDT) temperatures for eggs and nymphs were estimated to be 16.0 and 17.9°C for L. hyalinus, and 16.1 and 19.7°C for N. simulans, respectively. Thermal requirements for egg and nymphal development were 68.6 and 114.8 DD for L. hyalinus, and 77.7 and 190.3 DD for N. simulans, respectively. Reproduction and adult longevity were studied at 22, 26, 30, and 34°C. For both species preoviposition time decreased as temperature increased, and the oviposition period was longest at 26°C. The highest fecundity and egg viability were observed at 30°C, whereas longevities were higher at 22-26°C than at 30-34°C. As the lowest tested temperatures were not suitable to both heteropterans and 30°C was found to be the optimal temperature for development and reproduction, peak densities are expected in warm areas and seasons.


Assuntos
Heterópteros , Temperatura , Zea mays , Animais , Biologia , Dieta , Feminino , Heterópteros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Óvulo
3.
J Insect Sci ; 21(5)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34618901

RESUMO

A method for rearing the southern green stinkbug, (Nezara viridula L.) (Heteroptera: Pentatomidae), using a modified lygus semi-solid artificial diet was developed. First to second-instar nymph were reared in a density of 631.5 ± 125.05 eggs per Petri-dish (4 cm deep × 15 cm diam). Second instar to adult were reared in a density of 535.0 ± 112.46 s instar nymphs per rearing cage (43 × 28 × 9 cm). Mating and oviposition occurred in popup rearing cages (30 × 30 cm), each holding 60-90 mixed sex adults of similar age. Adults emerged 35.88 ± 2.13 d after oviposition and survived for an average of 43.09 ± 9.53 d. On average, adults laid 223.95 ± 69.88 eggs in their lifetime, for a total production of 8,099 ± 1,277 fertile eggs/oviposition cage. Egg fertility was 77.93% ± 16.28. Egg masses held in petri-dishes had a total hatchability of 79.38% ± 20.03. Mortality of early nymphs in petri-dishes was 0.64% ± 0.12 for the first instar and 1.37% ± 0.45 for second instar. Late nymphal mortality in rearing cages was 1.41% ± 0.10, 3.47% ± 1.27, and 4.72% ± 1.29 for the third, fourth, and fifth instars, respectively. Survivorship from nymphs to adults was 88.48% ± 2.76. Using artificial diet for rearing N. viridula could reduce cost by avoiding time-consuming issues with daily feeding fresh natural hosts and insect manipulation. It could increase reliability and simplicity of bug production, which should facilitate mass rearing of its biological control agents.


Assuntos
Ração Animal , Heterópteros/crescimento & desenvolvimento , Animais , Agentes de Controle Biológico , Fertilidade , Heterópteros/fisiologia , Laboratórios , Mortalidade , Oviposição , Reprodução
4.
J Chem Ecol ; 47(8-9): 747-754, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34550513

RESUMO

Plant Growth-Promoting Rhizobacteria (PGPR) induce systemic resistance (SR) in plants, decreasing the development of phytopathogens. The FZB42 strain of Bacillus velezensis is known to induce an SR against pathogens in various plant species. Previous studies suggested that it could also influence the interactions between plants and associated pests. However, insects have developed several strategies to counteract plant defenses, including salivary proteins that allow the insect escaping detection, manipulating defensive pathways to its advantage, deactivating early signaling processes, or detoxifying secondary metabolites. Because Brown Marmorated Stink Bug (BMSB) Halyomorpha halys is highly invasive and polyphagous, we hypothesized that it could detect the PGPR-induced systemic defenses in the plant, and efficiently adapt its salivary compounds to counteract them. Therefore, we inoculated a beneficial rhizobacterium on Vicia faba roots and soil, previous to plant infestation with BMSB. Salivary gland proteome of BMSB was analyzed by LC-MS/MS and a label-free quantitative proteomic method. Among the differentially expressed proteins, most were up-regulated in salivary glands of insects exposed to PGPR-treated plants for 24 h. We could confirm that BMSB was confronted with a stress during feeding on PGPR-treated plants. The to-be-confirmed defensive state of the plant would have been rapidly detected by the invasive H. halys pest, which consequently modified its salivary proteins. Among the up-regulated proteins, many could be associated with a role in plant defense counteraction, and more especially in allelochemicals detoxification or sequestration.


Assuntos
Bacillus/crescimento & desenvolvimento , Heterópteros/metabolismo , Proteínas e Peptídeos Salivares/análise , Vicia faba/microbiologia , Animais , Cromatografia Líquida de Alta Pressão , Heterópteros/crescimento & desenvolvimento , Larva/metabolismo , Glândulas Salivares/metabolismo , Estresse Fisiológico , Espectrometria de Massas em Tandem , Regulação para Cima , Vicia faba/química , Vicia faba/parasitologia
5.
J Insect Physiol ; 133: 104273, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34181983

RESUMO

Solar ultraviolet radiation (UV) can have a wide range of negative effects on animal fitness that take place not only during, but also after exposure (carryover effects). UV-induced carryover effects and potential adaptations to avoid or mitigate them are understudied in terrestrial animals, including arthropods and their potentially most vulnerable life stages. The spined soldier bug, Podisus maculiventris, increases the emergence of its eggs that are exposed to UV radiation by coating them in sunscreen-like pigmentation, but consequences of these conditions of embryonic development for nymphs and adults are unknown. We measured stink bug nymph survival, adult size and sex ratio following exposure of differently pigmented eggs across a range of UV intensities. Nymph survival to adulthood decreased with higher intensity of embryonic UV exposure and this carryover effect decreased with higher level of egg pigmentation, similar to previously observed effects on embryonic survival. Nymph development time, adult size and sex ratio were not affected by embryonic exposure to UV radiation nor by photoprotective egg pigmentation. This study is the first to demonstrate the potential for lethal carryover effects of UV radiation in terrestrial insects, highlighting the need for more studies of how this pervasive environmental stressor can affect fitness across life stages.


Assuntos
Heterópteros/efeitos da radiação , Pigmentação/fisiologia , Pigmentos Biológicos/fisiologia , Raios Ultravioleta/efeitos adversos , Animais , Heterópteros/crescimento & desenvolvimento , Longevidade , Ninfa/crescimento & desenvolvimento , Ninfa/efeitos da radiação , Óvulo/fisiologia , Óvulo/efeitos da radiação
6.
J Insect Sci ; 21(3)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33974081

RESUMO

The minute pirate bug Orius insidiosus (Say) is an important predator in mango agroecosystems. It attacks several species of thrips, particularly Frankliniella invasor Sakimura, which is considered a species of economic importance in mango. We investigated the effect of six diets on the development, survival, and reproduction of O. insidiosus: 1) first instars of F. invasor, 2) second instars, 3) adults, 4) pollen, 5) pollen plus thrips larvae, and 6) water. Individuals fed on thrips larvae, with or without pollen, completed their immature development significantly faster. Nymphs of O. insidiosus were able to complete their development feeding on pollen only, while individuals that received water as a diet were unable to reach the adult stage. The highest intrinsic growth rate was obtained when O. insidiosus were fed on pollen plus thrips larvae, and the lowest when individuals were fed on thrips adults. Our studies show that a diet of pollen plus F. invasor larvae is optimal for O. insidiosus development and population growth.


Assuntos
Agentes de Controle Biológico , Heterópteros/crescimento & desenvolvimento , Tisanópteros , Ração Animal , Animais , Larva/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Controle de Pragas , Pólen , Comportamento Predatório
7.
PLoS One ; 16(3): e0238336, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33755694

RESUMO

Animals have evolved the capacity to learn, and the conventional view is that learning allows individuals to improve foraging decisions. The parasitoid Telenomus podisi has been shown to parasitize eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of its coevolved host, Podisus maculiventris, but the parasitoid cannot complete its development in the exotic species. We hypothesized that T. podisi learns to exploit cues from this non-coevolved species, thereby increasing unsuccessful parasitism rates. We conducted bioassays to compare the responses of naïve vs. experienced parasitoids on chemical footprints left by one of the two host species. Both naïve and experienced females showed a higher response to footprints of P. maculiventris than of H. halys. Furthermore, parasitoids that gained an experience on H. halys significantly increased their residence time within the arena and the frequency of re-encounter with the area contaminated by chemical cues. Hence, our study describes detrimental learning where a parasitoid learns to associate chemical cues from an unsuitable host, potentially re-enforcing a reproductive cul-de-sac (evolutionary trap). Maladaptive learning in the T. podisi-H. halys association could have consequences for population dynamics of sympatric native and exotic host species.


Assuntos
Heterópteros/fisiologia , Vespas/parasitologia , Animais , Feminino , Heterópteros/efeitos dos fármacos , Heterópteros/crescimento & desenvolvimento , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Oviposição , Feromônios/farmacologia
8.
Bull Entomol Res ; 111(4): 429-437, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33583442

RESUMO

The predatory mirid Macrolophus praeclarus is widely distributed throughout the Americas, and is reported to prey upon several horticultural pest species. However, little is known about its biology, thermal requirements, crop odour preferences, phytophagy, and capability to induce defensive responses in plants. When five temperatures studied (20, 25, 30, 33 and 35°C) were tested and Ephestia kuehniella was used as prey, the developmental time from egg to adult on tomato, was longest at 20°C (56.3 d) and shortest at 33°C (22.7 d). The ability of nymphs to develop to adults decreased as the temperature increased, with the highest number of nymphs reaching the adult stage at 20°C (78.0%) and lowest at 35°C (0%). The lower and upper developmental thresholds were estimated at 11.2° and 35.3°C, respectively. The maximum developmental rate occurred at 31.7°C and the thermal constant was 454.0 ± 8.1 degree days. The highest predation rate of E. kuehniella eggs was obtained at 30°C. In Y-tube olfactory choice tests, M. praeclarus selected tomato, sweet pepper and eggplant odours more frequently than no plant control treatment. Macrolophus praeclarus feeding did not damage tomato plants compared to another zoophytophagous mirid, Nesidiocoris tenuis, which caused necrotic rings. The phytophagy of M. praeclarus induced defensive responses in tomato plants through the upregulation of the jasmonic acid metabolic pathway. The implications of the findings for using M. praeclarus in tomato biological control programmes in the Americas are discussed.


Assuntos
Hemípteros , Heterópteros/crescimento & desenvolvimento , Controle Biológico de Vetores , Comportamento Predatório , Animais , Feminino , Herbivoria , Solanum lycopersicum , Masculino , Temperatura , Clima Tropical
9.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33400796

RESUMO

The western tarnished plant bug, Lygus hesperus Knight, overwinters as a diapausing adult in response to short day lengths. Once environmental conditions are favorable, the bugs revert to an active reproductive state. To determine the impact on life-history traits of diverting resources toward diapause rather than oogenesis during early adulthood, diapausing and nondiapausing L. hesperus females were reared from the same cohorts. Body mass, ovarian maturation, ovipositional activity, and survivorship were monitored starting either at the time of release from diapause-inducing conditions or at adult eclosion for diapausers and nondiapausers, respectively. Females that had gone through 2 wk of diapause were larger and able to mobilize the resources necessary for oogenesis faster than nondiapausers, initiating oogenesis and ovipositing sooner and at a faster initial rate. However, lifetime egg production and average daily rates were similar for both groups. Postdiapausers lived longer than nondiapausers by an average of 19 d, which is five more than the 2-wk period when they were reproductively senescent. Overall, the results indicate that short-term diapause does not have a negative impact on life history. Furthermore, the extra endogenous resources stored during diapause may be able to enhance the alacrity with which the female can take advantage of improved environmental conditions and may prolong life by shielding the females against environmental stressors such as temperature extremes, oxidative agents, or food deficits.


Assuntos
Diapausa de Inseto , Heterópteros/fisiologia , Características de História de Vida , Oogênese , Oviposição , Animais , Feminino , Heterópteros/crescimento & desenvolvimento
10.
Insect Sci ; 28(1): 191-202, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31990127

RESUMO

The predatory bug, Orius majusculus (Reuter), is an important predator of thrips commercially produced for augmentative releases using the eggs of the Mediterranean flour moth Ephestia kuehniella (Zeller). In this study, we assessed the potential for using frozen adults of fruit flies, Drosophila melanogaster (Meigen), either as nymphal rearing diet or as diet throughout the entire life-cycle. We compared life-history traits and reproduction of predators when fed D. melanogaster with high lipid body content (lipid-rich) and with high protein body content (protein-rich), using a diet of 100% E. kuehniella eggs as control. We also analyzed the biochemical composition of both prey and predator in order to assess the nutritional quality of each diet, which partially explained the adequacy of the different diets for O. majusculus. There were significant differences between predators fed the two types of D. melanogaster, with the protein-rich flies as diet providing the best results in terms of mortality and fecundity. Furthermore, we show that while feeding O. majusculus throughout their development with D. melanogaster increases mortality and reduces reproduction, protein-rich D. melanogaster can be used as nymphal diet with minimal reduction in reproductivity and minimal increase in mortality.


Assuntos
Ração Animal/análise , Drosophila melanogaster/química , Heterópteros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Controle Biológico de Vetores , Animais , Dieta , Feminino , Masculino , Valor Nutritivo
11.
Insect Sci ; 28(2): 430-444, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32108427

RESUMO

Apolygus lucorum is the dominant pathogenic insect attacking Bacillus thuringiensis (Bt) cotton in China. Additionally, 20-hydroxyecdysone (20E) has important functions in many biological processes, including insect reproduction. Phospholipase C (PLC), which is an essential enzyme for phosphoinositide metabolism, is involved in 20E signal transduction, but its function in 20E-mediated reproduction in A. lucorum remains unclear. In this study, 20E increased AlPLCγ transcription as well as the abundance and activity of the encoded protein during molting and metamorphosis. The 20E treatment also induced the considerable accumulation of two second messengers, inositol triphosphate and diacylglycerol. The expression levels of genes encoding vitellogenin (AlVg) and soluble trehalase (AlTre-1) were similar to those of AlPLCγ, and were upregulated in response to 20E. The silencing of AlPLCγ resulted in downregulated expression of AlTre-1 and AlVg. However, the silencing of AlTre-1 and AlVg did not affect AlPLCγ expression. Moreover, the silencing of AlVg did not alter AlTre-1 expression. Furthermore, an examination of the insect specimens indicated that AlPLCγ is required for female adult reproduction, and that downregulated expression of this gene is associated with decreases in fecundity, adult longevity, and egg hatching rate as well as delayed oocyte maturation. We propose that 20E regulates AlTre-1 expression via AlPLCγ and affects Vg expression as well as ovary development to facilitate the reproductive activities of A. lucorum females.


Assuntos
Heterópteros/fisiologia , Proteínas de Insetos/genética , Fosfolipase C gama/genética , Trealase/metabolismo , Sequência de Aminoácidos , Animais , Ecdisterona/administração & dosagem , Feminino , Fertilidade/efeitos dos fármacos , Heterópteros/genética , Heterópteros/crescimento & desenvolvimento , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Fosfolipase C gama/química , Fosfolipase C gama/metabolismo , Filogenia
12.
J Exp Zool B Mol Dev Evol ; 336(1): 73-78, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33351288

RESUMO

Insecta is known to be the most diverse group of species, exhibiting numerous forms of endosymbiotic associations. Molecular techniques have provided significant indicators for insect-microbe interactions. The present study aimed to register one of the true bugs of pentatomomorpha and clarify its taxonomic position through phylogenetic analysis of the partial 16S rRNA gene region. A maximum likelihood analysis retrieved a generally well-supported phylogeny based on Tamura 3-parameter model. Based on the partial mitochondrial 16S rRNA gene sequences, a phylogenetic study of suborder Heteroptera relationships within Hemipteras' order was constructed. Sequences of 221 bases of the 3' end of the gene from 28 species within 16 families were analyzed. This analysis and bootstrap confidence revealed two major clades comprising four suborders within Hemiptera, with a close relationship between Heteroptera + (Sternorrhyncha + (Auchenorrhycha + Coleorrhyncha)). Infraorder Pentatomomorpha is forming a sister group with a substantial bootstrap value to Cimicomorpha. Pyrrhocoroidea forms a sister relationship with Lygaeoidea + Coreoidea. There is a close relationship between Largidae and Pyrrhocoridae within Pyrrhocoroidea. The results show that the present species is firmly embedded in the genus Arhaphe with 94.35% sequence resemblance to its congeners. Besides, the recovered hemipteran species considered a potential model group for studying different symbionts. We propose both phylogenetic and ecological evolutionary developmental biology viewpoints for a more synthetic understanding of insect populations' molecular evolution.


Assuntos
Heterópteros/crescimento & desenvolvimento , Heterópteros/genética , Filogenia , Animais , Simbiose
13.
J Insect Sci ; 20(5)2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32936895

RESUMO

The southern green stink bug (SGSB), Nezara viridula (L.), is an important agricultural pest in the United States. Limited information is available on the morphology of the female's reproductive system in relation to morphological changes associated with the number of eggs produced and egg masses oviposited. The ability to assess reproductive health and reproductive status based on ovarian morphology (i.e., physiological age-grading) can be an important tool for evaluating field populations and laboratory colonies intended for the application of different management strategies and experimental trials. Thus, the goal of this study was to develop a physiological age-grading system for SGSB. Females aged from 0 to 79 d chronologically randomly selected from laboratory colonies and dissected to assess ovarian morphology. Specific morphological differences in ovarian structures including differentiation of the ovarioles, deposition of yolk in the most proximal follicle, quantity and appearance of follicular relics, expansion of the lateral oviducts, and number of developing follicles per ovariole were related to chronological age, the number of eggs produced and number of egg masses. Based on specific combinations of these morphological characteristics, the continuum of ovarian development was divided into three nulliparous (i.e., 'no eggs'; N1, N2, and N3) and three parous stages (i.e., 'with eggs'; P1, P2, and P3). Direct relationships were noted between number of eggs produced and physiological age with over 7-fold higher number of eggs and 14-fold higher number of egg masses associated with the P2 and P3 stages, respectively.


Assuntos
Entomologia/métodos , Heterópteros/fisiologia , Controle de Insetos/métodos , Fatores Etários , Animais , Heterópteros/crescimento & desenvolvimento , Óvulo/crescimento & desenvolvimento , Fisiologia/métodos
14.
Sci Rep ; 10(1): 15231, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943688

RESUMO

Cold winter temperatures can influence insects' survival in temperate zones. Brown marmorated stink bug, Halyomorpha halys (Stål) overwinters as adults in natural and human-made structures. In this study, we characterized low temperature mortality rates of H. halys adults that were either entering (ENA) or exiting (EXA) overwintering microhabitats. We considered the effect of different duration of cold exposure on mortality. We determined the impact of insect nutritional status and weight on cold tolerance. We additionally evaluated the effects of cold exposure on H. halys adult longevity and fecundity. Mortality of ENA and EXA adults was determined for 6 h and 2 h periods at - 2.5 °C and 2.5 °C respectively. EXA adults displayed higher mortality rates compared to ENA individuals at the low-temperature regimes. Halyomorpha halys adult survival rate was higher when their nutrient index (EXA individuals only) and weight were high. Low-temperature exposure increased longevity, but reduced fecundity of ENA females. The data further highlight how extreme spring frost events can result in significantly increased mortality levels of H. halys adults.


Assuntos
Heterópteros/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Temperatura Baixa , Ecossistema , Feminino , Fertilidade , Heterópteros/anatomia & histologia , Heterópteros/crescimento & desenvolvimento , Longevidade , Masculino , Estações do Ano
15.
Arch Insect Biochem Physiol ; 104(4): e21690, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32394499

RESUMO

The harlequin bug (HB), Murgantia histrionica, is a major pest of cabbage family plants throughout its range in the United States. RNA interference (RNAi) is a posttranscriptional gene silencing mechanism that is showing promise as a biopesticide due to the ability to target species-specific genes necessary for growth and/or survival with synthetic double-stranded RNA (dsRNA). In the present study, dsRNA stability assays revealed that nucleases present in the saliva of harlequin bugs did not rapidly degrade dsRNA. We tracked the movement and localization of radioactively labeled dsRNA in both mustard plant seedlings and harlequin bug nymphs that fed on treated host plants. Movement of 32 P-labeled-dsRNA from soil to plant and plant to insect was detected. The efficacy of RNAi in inducing mortality in harlequin bug adults and nymphs injected or fed with dsRNA targeting inhibitor of apoptosis (IAP), ATPase N2B (ATPase), serine/threonine-protein phosphatase PP1-ß catalytic subunit (PP1), signal recognition particle 54 kDa protein (SRP), and G protein-coupled receptor 161-like (GPCR) genes was evaluated. Injection of dsRNA targeting candidate genes into adults caused between 40% and 75% mortality and induced significant knockdown of target gene expression. Feeding dsRNA targeting the IAP gene to nymphs by plant-mediated and droplet feeding methods induced knockdown of the target gene and caused 40-55% mortality. These findings suggest that RNAi may be a viable approach for managing this pest.


Assuntos
Heterópteros/genética , Mostardeira/metabolismo , Interferência de RNA , Animais , Perfilação da Expressão Gênica , Heterópteros/crescimento & desenvolvimento , Heterópteros/metabolismo , Proteínas Inibidoras de Apoptose/genética , Controle de Insetos/métodos , Mostardeira/parasitologia , Ninfa/genética , Ninfa/metabolismo , Fenômenos Fisiológicos Vegetais , RNA de Cadeia Dupla , Ribonucleases , Saliva/enzimologia , Solo/química
16.
Folia Parasitol (Praha) ; 672020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32350156

RESUMO

Here we describe the new trypanosomatid, Phytomonas borealis sp. n., from the midgut of the spiked shieldbugs, Picromerus bidens (Linnaeus), collected in two locations, Novgorod and Pskov Oblasts of Russia. The phylogenetic analyses, based on the 18S rRNA gene, demonstrated that this flagellate is a sister species to the secondary monoxenous Phytomonas nordicus Frolov et Malysheva, 1993, which was concurrently documented in the same host species in Pskov Oblast. Unlike P. nordicus, which can complete its development (including exit to haemolymph and penetration into salivary glands) in Picromerus bidens, the new species did not form any extraintestinal stages in the host. It also did not produce endomastigotes, indispensable for transmission in other Phytomonas spp. These observations, along with the fact that P. bidens overwinters at the egg stage, led us to the conclusion that the examined infections with P. borealis were non-specific. Strikingly, the flagellates from the Novgorod population contained prokaryotic endosymbionts, whereas the parasites from the second locality were endosymbiont-free. This is a first case documenting presence of intracellular symbiotic bacteria in Phytomonas spp. We suggest that this novel endosymbiotic association arose very recently and did not become obligate yet. Further investigation of P. borealis and its intracellular bacteria may shed light on the origin and early evolution of endosymbiosis in trypanosomatids.


Assuntos
Fenômenos Fisiológicos Bacterianos , Heterópteros/parasitologia , Simbiose , Trypanosomatina/classificação , Animais , Heterópteros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia , Filogenia , RNA de Protozoário/análise , RNA Ribossômico 18S/análise , Federação Russa , Trypanosomatina/microbiologia
17.
Mol Biol Evol ; 37(6): 1775-1789, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32101294

RESUMO

Evidence accumulates that the functional plasticity of insulin and insulin-like growth factor signaling in insects could spring, among others, from the multiplicity of insulin receptors (InRs). Their multiple variants may be implemented in the control of insect polyphenism, such as wing or caste polyphenism. Here, we present a comprehensive phylogenetic analysis of insect InR sequences in 118 species from 23 orders and investigate the role of three InRs identified in the linden bug, Pyrrhocoris apterus, in wing polymorphism control. We identified two gene clusters (Clusters I and II) resulting from an ancestral duplication in a late ancestor of winged insects, which remained conserved in most lineages, only in some of them being subject to further duplications or losses. One remarkable yet neglected feature of InR evolution is the loss of the tyrosine kinase catalytic domain, giving rise to decoys of InR in both clusters. Within the Cluster I, we confirmed the presence of the secreted decoy of insulin receptor in all studied Muscomorpha. More importantly, we described a new tyrosine kinase-less gene (DR2) in the Cluster II, conserved in apical Holometabola for ∼300 My. We differentially silenced the three P. apterus InRs and confirmed their participation in wing polymorphism control. We observed a pattern of Cluster I and Cluster II InRs impact on wing development, which differed from that postulated in planthoppers, suggesting an independent establishment of insulin/insulin-like growth factor signaling control over wing development, leading to idiosyncrasies in the co-option of multiple InRs in polyphenism control in different taxa.


Assuntos
Evolução Biológica , Insetos/genética , Receptor de Insulina/genética , Asas de Animais/anatomia & histologia , Animais , Feminino , Duplicação Gênica , Heterópteros/genética , Heterópteros/crescimento & desenvolvimento , Insetos/anatomia & histologia , Masculino , Asas de Animais/crescimento & desenvolvimento
18.
Neotrop Entomol ; 49(2): 191-202, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31989407

RESUMO

Aquatic systems have been degraded by environmental changes aimed at increasing the productivity of farmland and ranches. These changes affect aquatic assemblages at both local and regional scales. The hypothesis of this study is that in-stream environmental conditions are more important determinants of species richness and composition of Gerromorpha assemblage, given that they are affected directly by changes that occur within the stream, rather than by landscape conditions. To test our hypothesis, we collected at 20 sites of agricultural and forested regions in the Brazilian Cerrado. We relate predictors of the landscape and sites, of the streams with the assemblages of Heteroptera. While landscape metrics play an important role in the formation of stream conditions, local and physico-chemical variables had a significant influence on the structure of the Gerromorpha assemblages in the study area. This indicates that these organisms are more dependent on the processes that occur within the stream than those that occur outside the area of the gallery forest, considering the spatial scale of this study.


Assuntos
Heterópteros/crescimento & desenvolvimento , Rios , Agricultura , Animais , Brasil , Florestas , Pradaria , Dinâmica Populacional
19.
Int J Mol Sci ; 21(2)2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31963875

RESUMO

The existence of a temperature effect of insecticides frustrated the control of the green plant bug Apolygus lucorum (Meyer-Dür). Previous studies mostly focused on the application of insecticides, but the underlying mechanism remains incompletely understood. Here, we report a transcriptome profiling of A. lucorum treated by three kinds of temperature coefficient insecticides (TCIs) (positive TCI: imidacloprid, negative TCI: b-cypermethrin and non-effect TCI: phoxim) at 15 °C, 25 °C and 35 °C by using next- and third-generation RNA-Seq methods. A total of 34,739 transcripts were annotated from 277.74 Gb of clean data. There were more up-regulated transcripts than down-regulated transcripts in all three kinds of TCI treatments. Further Venn diagrams indicate the regulatory transcripts and regulatory modes were different at the three temperatures. The responses to imidacloprid involved more detox and stress response transcripts such as cytochrome P450 (CYP450), carboxylesterase (CarE) and catalase (CAT) at 35 °C, which was the case for beta-cypermethrin at 15 °C. UDP-glucuronyltransferase (UGT) and heat shock protein (HSP) transcripts were heavily involved, and thus deserve particular note in the temperature effect of insecticides. This high-confidence transcriptome atlas provides improved gene information for further study on the insecticide temperature effect related physiological and biochemical processes of A. lucorum.


Assuntos
Perfilação da Expressão Gênica/métodos , Heterópteros/crescimento & desenvolvimento , Proteínas de Insetos/genética , Inseticidas/farmacologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Heterópteros/genética , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Compostos Organotiofosforados/farmacologia , Piretrinas/farmacologia , Análise de Sequência de RNA , Temperatura
20.
Insect Sci ; 27(5): 1125-1134, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31420911

RESUMO

Development of conservation biological control programs requires the identification of sources that contribute to predator colonization of crops. Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) is an efficient polyphagous predator used in biological control programs in vegetable crops in Europe. We have developed a marking method based on spraying with a solution of the brine shrimp Artemia spp. (Anostraca: Artemiidae) cysts, followed by a PCR detection of Artemia DNA to monitor M. pygmaeus dispersal from banker plants to tomato crops. Experiments conducted in climatic chambers show that the topical application of this marking solution on M. pygmaeus does not significantly reduce adult longevity and that it is detected up to 6 d after the application. When this Artemia solution was applied on Calendula officinalis L. banker plants harboring M. pygmaeus and maintained outdoors, Artemia DNA was still detected on 62% of the insects after 6 d. The conducted field applications in commercial greenhouses have confirmed the usefulness of this method to monitor M. pygmaeus dispersal from banker plants to a newly planted tomato crop. This method can be used to assess arthropod movement, being an interesting molecular approach for further improving future pest management strategies.


Assuntos
Distribuição Animal , Heterópteros/fisiologia , Controle Biológico de Vetores/métodos , Reação em Cadeia da Polimerase/métodos , Comportamento Predatório , Animais , Feminino , Heterópteros/crescimento & desenvolvimento , Controle de Insetos/métodos , Solanum lycopersicum/crescimento & desenvolvimento , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia
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