Noctuóideos e parasitoides associados à soja não-Bt e Bt (Cry1Ac) no Cerrado

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Zoologia, 2016.O Brasil é o segundo maior produtor de soja do mundo, com áreas de cultivo ocupando 3,5% do território nacional. Grande parte da produtividade é oriunda de cultivares transgênicas que expressam a toxina Cry1Ac de Bacillus thuringiensis Berliner, que visam reduzir densidades populacionais dos lepidópteros praga-chave. A cienciometria realizada nos registros do sítio Web of ScienceTM, aponta um número crescente de pesquisas envolvendo toxinas Cry e os noctuóideos, buscando estratégias e soluções para uma melhor gestão dos agroecossistemas. O trabalho foi desenvolvido em cultivo de soja não-Bt e Bt sem a utilização de inseticidas, na safra 2015/2016, na área experimental da Embrapa Cerrados, Planaltina, DF. Foram listadas 13 espécies de noctuóideos associados à cultura da soja, registrando-se pela primeira vez as espécies Elaphria deltoides (Möschler, 1880) e Utetheisa ornatrix (Linnaeus,1758). A baixa incidência de lagartas em campo não atingiu o nível de controle, no entanto o número de lagartas coletadas na soja não-Bt foi 11,5 vezes superior ao encontrado na soja Bt, indicando os efeitos da toxina Cry1Ac sobre os noctuóideos associados à soja. Dessa forma, reforça-se a necessidade de monitoramento das áreas de cultivos de soja, visando a melhor avaliação dos reais acontecimentos em nível de campo. Ao final, aponta-se que o os parasitoides foram beneficiados pelo manejo da área experimental sem a utilização de inseticidas, proporcionando o controle biológico natural com uma taxa de parasitismo superior a 35%.Brazil is the second largest producer country of soybean in the world, with crop areas occupying 3.5% of the national territory. Most of the productivity comes from transgenic varieties that express the Cry1Ac toxin from Bacillus thuringiensis Berliner, which aim to reduce the population densities of the moth key pests. In the cienciometry carried out by the registries on the Web of ScienceTM, it is pointed out an increase of investigations involving Cry toxins and noctuids, searching strategies and solutions for a better management of the agroecosystems. Our study realized in the 2015/2016 crops in the experimental area of Embrapa Cerrados, Planaltina, DF on non-Bt and Bt soybean cultivation areas without insecticides sprayed reports a total of 13 species of noctuids associated with soybean cultivation, with Elaphria deltoides (Möschler, 1880) and Utetheisa ornatrix (Linnaeus,1758) being registered for the first time. The low incidence of caterpillars in the field did not reach the Control Level, however the number of caterpillars collected in non-Bt soybean was 11.5 times higher than that found in Bt soybean, indicating the effects of the Cry1Ac toxin on the noctuids associated with soybean. Therefore, it is necessary to reinforce monitor soybean crop areas, aiming at the best evaluation of the real events at the field level. It is pointed out that the parasitoids were benefited by the management of the experimental area without the use of insecticides, providing the natural biological control with a parasitism rate up to 35%

CARACTERIZAÇÃO MORFOLÓGICA DOS ESTÁGIOS IMATUROS DE Rachiplusia nu (GUENÉE, 1852) (LEPIDOPTERA: NOCTUIDAE: PLUSIINAE) E LISTA DE PLANTAS HOSPEDEIRAS

Rachiplusia nu (Guenée, 1852) é um noctuídeo cujas lagartas são vulgarmente conhecidas como “falsas-medideiras”. O hábito polífago e a voracidade das larvas têm tornado essa espécie uma das principais desfolhadoras de plantas cultivadas herbáceas no Sul do Brasil e em países do Cone Sul. Esse estudo teve como objetivo caracterizar a morfologia dos estágios imaturos de R. nu (Lepidoptera: Noctuidae: Plusiinae) e fornecer uma listagem atualizada das plantas hospedeiras. Os insetos foram coletados na localidade de Tuiuty em Bento Gonçalves (Rio Grande do Sul - Brasil) com o auxílio de armadilha luminosa. A criação foi conduzida sob as condições controladas 25 ± 1ºC, 70 ± 10% UR e fotofase de 14 horas. As lagartas foram alimentadas com dieta artificial e os adultos com solução de mel a 10%. Para caracterização morfológica foram preservados exemplares de cada fase de desenvolvimento em álcool 70%. Foi verificado na quetotaxia da lagarta que a cerda L3 nos segmentos torácicos T1, T2, T3, nos segmentos abdominais A1-A4, SD1 está presente acima da SD2, vertical a D2, apenas em A10 as cerdas L1, L2, L3, não foram localizadas. Foram registradas 56 espécies de plantas hospedeiras para R. nu pertencentes à 18 famílias botânicas

Movement of \u3ci\u3eStriacosta albicosta\u3c/i\u3e (Smith) (Lepidoptera: Noctuidae) Larvae on Transgenic \u3ci\u3eBt\u3c/i\u3e and Non-\u3ci\u3eBt\u3c/i\u3e Maize

Exposure of lepidopteran pests to Bacillus thuringiensis (Bt) proteins has been shown to affect the behavior of larvae, including increased movement and avoidance of Bt-expressing plants or diet. Therefore, we hypothesized that the behavior of western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), an important pest of maize, could be affected when exposed to Bt plants. To test this hypothesis, we conducted a series of artificial arena and on-plant experiments to determine S. albicosta neonate behavior when exposed to Bt and non-Bt plant tissue. Video tracking experiments presented neonate larvae with the choice of Bt or non-Bt pollen in a Petri dish for 15 min while being video recorded for analysis with EthoVision software. This study showed an increase in mean velocity and total time spent moving for larvae in the presence of Cry1F vs. non-Bt when compared with Vip3A vs. non-Bt or Cry1F vs. Vip3A. However, there was no difference in total distance moved or time spent in the food zone for all scenarios. Maize tissue choice experiments allowed neonatal larvae the choice of feeding on Bt or non-Bt tassel or leaves for 9 h in Petri dish arenas. This experiment showed that larvae preferred tassel tissue over leaves but did not indicate that larvae could distinguish between Bt and non-Bt tissue. In contrast, on-plant experiments (including a whole plant neonate dispersal study under controlled conditions and an in-field silking behavior experiment) indicated that the presence of Cry1F and Vip3A Bt toxins increased plant abandonment, suggesting that larvae are able to detect and avoid Bt toxins. The discrepancy of these results is likely due to the on-plant studies providing more field-realistic environmental conditions and a longer duration of exposure to Bt toxins for the behavioral experiments. Our results represent the first steps in understanding the complex behavior of S. albicosta when exposed to Bt plants. A better understanding of the response of larvae when exposed to Bt traits can aid in the management of this pest, particularly for the design of resistance management strategies and refuge design

Noctuóides (Lepidoptera: Noctuoidea) associados a soja Bt e não-Bt no Cerrado brasileiro

O uso de OGM que expressam toxina Bt na produção de soja tem aumentado significativamente nos últimos anos no Brasil e são utilizados para conter os danos causados ​​pelos lepidópteros pragas. Neste estudo comparamos a riqueza e a abundância de Noctuoides (Noctuoidea) associados à soja Bt e não-Bt. Determinamos as variações temporais em função da fenologia e correlacionamos às variações populacionais das espécies mais comuns com variáveis ​​meteorológicas. A pesquisa foi conduzida na área experimental da Embrapa Cerrados. O método de coleta utilizado foi diferenciado sendo supressivo e absoluto. Um total de 13 espécies foram coletadas, das quais oito ocorreram em soja Bt. Os taxa mais representativos foram Chrysodeixis includens, Anticarsia gemmatalis e Spodoptera spp. O número de larvas pertencentes às espécies alvo da tecnologia Bt foram 10 vezes menores na soja Bt do que em soja não-Bt . Utetheisa ornatrix e Elaphria deltoides foram registradas na soja pela primeira vez, observando-se larvas de ambas espécies na soja não-Bt e as de U. ornatrix também na soja Bt. Somente as larvas de A. gemmatalis se correlacionaram (p <0,05) negativamente com a precipitação. Este estudo forneceu informações em campo sobre a abundância e riqueza de espécies na soja não- Bt, associada aos efeitos da soja Bt. A importância do monitoramento das lagartas é substancial, a fim de tomar a melhor decisão de controle, considerando-se os diferentes níveis de infestação entre cultivares como critério.The use of GMO expressing Bt toxin in soybean production has increased significantly in the last years in Brazil in order to manage the damage caused by lepidopteran pests. In this study, we compared the richness and abundance of owlet moths (Noctuoidea) associated with Bt and non-Bt soybean. We determined the temporal variations as a function of phenology, and correlated the population variations of the most common species with meteorological variables. The research was conducted at the experimental area of Embrapa Cerrados. The collection method used was differentiated being suppressive and absolute. A total of 13 species were collected, of which eight occurred on Bt soybeans. The most representative taxa were Chrysodeixis includens (72.87%), Anticarsia gemmatalis (18.17%) and Spodoptera spp (5.22%). The number of larvae belonging to species targeted by the Bt technology was 10 times lower on Bt than on non-Bt soybeans. Utetheisa ornatrix and Elaphria deltoides were recorded on soybean for the first time, observing larvae of both species in non-Bt soybean and those of U. ornatrix also in Bt soybean. Only A. gemmatalis larvae correlated (p <0.05) negatively with precipitation. This study provided field information on the abundance and species richness of owlet moths on non-Bt soybeans, associated with the effects of Bt soybean. When considering the different levels of infestation between cultivars as a criterion, larvae monitoring is of substantial importance in order to develop the lost control program

Comparação de duas dietas artificiais para criação de Elaphria agrotina

Com a crescente importância de Elaphria agrotina (Guenée) (Lepidoptera: Noctuidae) em cultivos de milho, especialmente no Bioma Cerrado, o presente trabalho objetivou comparar o seu desenvolvimento e sobrevivência em dieta artificial de Greene e Poitout & Bues (25±1ºC, 70±10% umidade relativa [UR] e fotofase de 12h). A dieta de Poitout & Bues foi mais adequada que a dieta de Grenne, proporcionando maior sobrevivência (77.51% e 5.57%), menor tempo de desenvolvimento (49.81 dias e 55.24 dias) e maior fecundidade (167.65 ovos e 84.9 ovos), respectivamente. Todas as lagartas alimentadas com dieta de Poitout & Bues passaram por seis instares, enquanto que praticamente metade das provenientes da dieta de Greene passou por um instar a menos. Lagartas alimentadas com dieta de Greene, apresentaram maior valor do tempo médio de cada geração (T) e menores valores das taxas líquida de reprodução (Ro), intrínseca de aumento (rm) e razão finita diária de aumento (λ). Os resultados deste estudo indicam a recomendação da dieta de Poitout & Bues para manutenção de colônias e criação massal de E. agrotina quando comparada com a dieta de Greene.Given the increasing importance of Elaphria agrotina (Guenée) (Lepidoptera: Noctuidae) in corn crops, especially in the Brazilian Savannah biome, the present research aimed to study its development and survival on Greene’s and Poitout & Bues’s artificial diets (25±1°C, 70±10% relative humidity [RH] and 12h photophase). Poitout & Bues’s diet was more suitable than Greene’s diet, providing higher survival percent (77.51% vs. 5.57%), lower development time (49.81 days vs. 55.24 days) and higher fecundity (167.65 vs. 84.9 eggs), respectively. All the caterpillars reared on Poitout & Bues’s diet passed through six instars, while almost half of the larvae reared on Greene’s diet went through one less instar stage. Regarding the main reproductive parameters, higher average time of generation (T) and lower values of net rates of reproduction (Ro), and increased (rm) intrinsic and finite reason of increase (λ), were observed for larvae reared on Greene’s diet. Results presented in this study indicated that Poitout & Bues’s diet is more suitable for maintenance of colonies of E. agrotina as compared to Greene’s diet

Comparison of two artificial diets to rear Elaphria agrotina

ABSTRACT: Given the increasing importance of Elaphria agrotina (Guenée) (Lepidoptera: Noctuidae) in corn crops, especially in the Brazilian Savannah biome, the present research aimed to study its development and survival on Greene’s and Poitout & Bues’s artificial diets (25±1°C, 70±10% relative humidity [RH] and 12h photophase). Poitout & Bues’s diet was more suitable than Greene’s diet, providing higher survival percent (77.51% vs. 5.57%), lower development time (49.81 days vs. 55.24 days) and higher fecundity (167.65 vs. 84.9 eggs), respectively. All the caterpillars reared on Poitout & Bues’s diet passed through six instars, while almost half of the larvae reared on Greene’s diet went through one less instar stage. Regarding the main reproductive parameters, higher average time of generation (T) and lower values of net rates of reproduction (Ro), and increased (rm) intrinsic and finite reason of increase (λ), were observed for larvae reared on Greene’s diet. Results presented in this study indicated that Poitout & Bues’s diet is more suitable for maintenance of colonies of E. agrotina as compared to Greene’s diet

Parasitoides associados com Helicoverpa armigera em áreas de refúgio de algodão, no Oeste da Bahia, Brasil

<div><p>ABSTRACT: Natural biological control is one of the major causes responsible for reduction of pest population in agricultural ecosystem. However, natural biological control importance is usually minimized by not being estimated. This study reports the occurrence of Campoletis sonorensis (Cameron, 1886) (Hymenoptera: Ichneumonidae), Archytas marmoratus (Townsend, 1915) and Archytas incertus (Macquart, 1851) (Diptera: Tachinidae) associated with Helicoverpa armigera (Hübner, 1809) (Lepidoptera: Noctuidae). The rate of larval parasitism was up to 41% in structured refuge areas of cotton, without chemical control with insecticides. This study strengthens our knowledge relating to parasitoids associated with natural control of H. armigera in the American continent. In addition, it documents the rule that structured refuge areas could play as a source of natural enemies, besides their contribution to production of non-selective populations to Bt technology.</p></div

Comparison of two artificial diets to rear Elaphria agrotina

<div><p>ABSTRACT: Given the increasing importance of Elaphria agrotina (Guenée) (Lepidoptera: Noctuidae) in corn crops, especially in the Brazilian Savannah biome, the present research aimed to study its development and survival on Greene’s and Poitout & Bues’s artificial diets (25±1°C, 70±10% relative humidity [RH] and 12h photophase). Poitout & Bues’s diet was more suitable than Greene’s diet, providing higher survival percent (77.51% vs. 5.57%), lower development time (49.81 days vs. 55.24 days) and higher fecundity (167.65 vs. 84.9 eggs), respectively. All the caterpillars reared on Poitout & Bues’s diet passed through six instars, while almost half of the larvae reared on Greene’s diet went through one less instar stage. Regarding the main reproductive parameters, higher average time of generation (T) and lower values of net rates of reproduction (Ro), and increased (rm) intrinsic and finite reason of increase (λ), were observed for larvae reared on Greene’s diet. Results presented in this study indicated that Poitout & Bues’s diet is more suitable for maintenance of colonies of E. agrotina as compared to Greene’s diet.</p></div