36 research outputs found
Aspectos ecológicos de parasitóides em lagartas de Lepidoptera em Caryocar brasiliense Camb. (Caryocaraceae) em um cerrado sensu stricto do Brasil Central
Este estudo quantificou a ocorrência de parasitóides em cinco espécies de lagartas de Lepidoptera que possuem Caryocar brasiliense como planta hospedeira, verificando se existe uma relação direta e positiva entre a abundância do hospedeiro e a proporção de parasitismo; se os abrigos utilizados pelas espécies de Lepidoptera atuam como pistas ou proteção contra os parasitóides; se o tamanho do hospedeiro influencia as taxas de parasitismo e se existe uma maior ocorrência de ataques de Diptera em comparação com Hymenoptera nas lagartas de Lepidoptera no cerrado do Distrito Federal, Brasil. O estudo foi realizado em uma área de cerrado sensu stricto da Fazenda Água Limpa no período de julho de 2003 a junho de 2004, à procura de lagartas folívoras externas. As lagartas foram mais parasitadas quando ocorreram em folhas maduras. Nola sp. (Noctuidae) apresentou a maior proporção de parasitismo em comparação com as outras espécies e foi a única espécie em que se verificou uma correlação negativa entre as taxas de parasitismo e o tamanho de seus indivíduos. As espécies de lagartas que constroem abrigos apresentaram menores porcentagens de parasitismo em comparação com as que vivem expostas. Os parasitóides da ordem Hymenoptera foram mais freqüentes que os Diptera. No geral, para as espécies de Lepidoptera em C. brasiliense, a riqueza de espécies de parasitóides e a porcentagem de parasitismo apresentaram associações com a densidade, a estratégia de vida, a dieta do hospedeiro e a qualidade nutricional da folha de C. brasiliense.This study quantified parasitoid occurrence on five lepidopteran caterpillars species that use Caryocar brasiliense as host plant, trying to verify if there was a direct relationship between host abundance and the proportion of parasitism; if leaf shelters served as cues or protection from parasitoids; if host size influenced the proportion of parasitism, and if attacks by Diptera were more frequent than by Hymenoptera. Searches for external folivorous caterpillars were carried out in an area of cerrado sensu stricto, from July/2003 to June/2004. Caterpillars were more parasitized when occurred on mature leaves. Nola sp. (Noctuiidae) had the highest proportion of parasitism and a negative correlation between their body size and parasitoid attack. Caterpillars that constructed shelters suffered lower parasitism than those exposed. Hymenopteran parasitoids were more abundant than Dipteran parasitoids attacking caterpillars on C. brasiliense leaves. In general, parasitoid species richness and the proportion of parasitism in lepidopteran caterpillar on C. brasiliense showed associations with host population density, their life strategy, diet and leaf nutritional quality
Arctiidae (Insecta: Lepidoptera) of the Boracéia Biological Station (Salesópolis, São Paulo, Brazil)
Uma lista das espécies de mariposas Arctiidae com registro de ocorrência para a Estação Biológica de Boracéia (EBB) é apresentada. Esta listagem foi obtida através da observação de material depositado em quatro coleções científicas brasileiras. Um total de 237 espécies foi registrado. A EBB está entre as localidades mais ricas em espécies de Arctiidae do Brasil.A checklist of the Arctiidae moth species with occurrence in the Boracéia Biological Station (EBB) is presented. The list was obtained from specimens deposited in four Brazilian scientific collections. A total of 237 arctiid species were recorded. The EBB is among the species-richest locations recorded in Brazil
Folivore caterpillars on Roupala montana Aubl. (Proteaceae) in Cerrado Sensu Stricto
No cerrado a riqueza de espécies de lepidópteros é alta e confirmada por registros de adultos, mas o conhecimento sobre as interações das lagartas com suas plantas hospedeiras ainda é incipiente. Os objetivos deste trabalho foram conhecer a riqueza de espécies de lepidópteros folívoros em Roupala montana Abl., a idade relativa das folhas consumidas pelas espécies e suas amplitudes de dietas. Os dados foram coletados em áreas de cerrado sensu stricto de Brasília de 1991 a 2004. As lagartas encontradas foram coletadas e criadas no laboratório. Foram registradas 62 espécies de lepidópteros de 22 famílias, consumindo folhas jovens (8%) e maduras (92%) de R. montana. Cerconota sciaphilina (Zeller) (Elachistidae), duas espécies de Gracillariidae e uma de Gelechiidae consumiram somente folhas jovens e, apresentaram ciclo de vida curto e sincronizado com a fenologia foliar da planta hospedeira. Das espécies que consomem folhas maduras, 36 foram consideradas polífagas e mostraram variação muito grande na utilização do recurso. Vinte e seis espécies foram encontradas somente em R. montana, sendo que 58% delas são bastante raras, o que dificulta análise de amplitude de dieta. As espécies monófagas em R. montana foram Chlamydastis platyspora (Meyrick) (Elachistidae), Stenoma cathosiota Meyrick (Elachistidae), Idalus prop. sublineata (Rothschild) (Arctiidae) e Eomichla sp. (Oecophoridae).Richness of lepidopteran species in the cerrado is high. The confirmation of this richness is based on adult records but knowledge of larvae-host plants interactions is still incipient. The main purpose of this work was to identify folivorous caterpillar species on Roupala montana Aubl. in areas of a Brazilian cerrado sensu stricto, their dietary range, and the relative age of the consumed leaves richness. Three data sets, collected from 1991 to 2004 were used in this study. All caterpillars found on the host plants in the field were collected and reared in the laboratory. Sixty-two lepidopteran species from 22 families were recorded; they were found feeding on new (8%) and mature (92%) leaves of R. montana. Cerconota sciaphilina (Zeller) (Elachistidae), two unidentified Gracillariidae species and, one species of Gelechiidae fed only on new leaves. These species showed a short life cycle, which was very syncronized with the host plant foliar phenology. Among the species feeding on mature leaves, 36 were considered polyphagous and, these showed a large variation in the use of the food resource. Twenty-six species were found only on R. montana, 58% were very rare, a character that difficults the analysis of their dietary range. The monophagous species on R. montana were: Chlamydastis platyspora (Meyrick) (Elachistidae), Stenoma cathosiota Meyrick (Elachistidae), Idalus prop. sublineata (Rothschild) (Arctiidae), and Eomichla sp. (Oecophoridae)
Species composition and temporal activity of Arctiinae (Lepidoptera: Erebidae) in two cerrado vegetation types
Arctiinae moths include nearly 11,000 species worldwide, of which approximately 700 species occur in the Brazilian Cerrado. The aim of this study was to describe the species composition of Arctiinae, as well as the variation in annual and nightly moth activity, in two Cerrado vegetation types. We sampled moths one night per month from September 2008 to June 2009, in the gallery forest and in the cerrado sensu stricto in the Jardim Botânico de Brasília. We collected 395 tiger moths belonging to 65 morphospecies; 74% of the species belonged to the tribe Arctiini and 26% to Lithosiini. Thirty-one species (47.7%) occurred only in the gallery forest, 13 (20%) occurred only in the cerrado sensu stricto, and 21 (32.3%) occurred in both vegetation types. Additionally, we found the greatest species richness between 7:00 p.m. and 8:00 p.m., and these hours were associated with 21 and 22 species, respectively. Most species (51.8%) were active for up to three hours during the night. In general, the species composition differed between the dry and rainy seasons, and the similarity of the fauna also varied hourly. Based on our results, we suggest that rapid inventories of Arctiinae be performed in both rainy and dry seasons, and sampling should be carried out the entire night
Defenses induced by herbivory and specific interactions on the tri-trophic system soybean-stink bug-egg parasitoids
O objetivo deste trabalho foi avaliar a influência de voláteis de soja, induzidos pela herbivoria dos percevejos Euschistus heros e Nezara viridula, no comportamento de busca de hospedeiros dos parasitoides Telenomus podisi e Trissolcus basalis. Plantas injuriadas pela alimentação dos percevejos foram utilizadas como estímulos em bioensaios com fêmeas dos parasitoides, em olfatômetro de dupla escolha tipo Y. Telenomus podisi respondeu somente a voláteis liberados pela soja após a herbivoria de E. heros, seu hospedeiro preferencial. Trissolcus basalis não foi influenciado pelas plantas injuriadas pelos percevejos. Os resultados obtidos indicam existência de interações espécie-específicas no sistema tritrófico soja-percevejos-parasitoides de ovos.The objective of this work was to evaluate the influence of soybean volatiles, induced by the herbivory of the stink bugs Euschistus heros and Nezara viridula, on the host searching behavior of the parasitoids Telenomus podisi and Trissolcus basalis. Plants injured by the feeding activity of the stink bugs were used as stimuli in bioassays with parasitoid females in a two-choice Y type olfactometer. Telenomus podisi responded only to volatiles released by soybean after herbivory injury of E. heros, their preferential host. Trissolcus basalis did not respond to plants injured by the stink bugs. The obtained results indicate the existence of species-specific interactions in the tri-trophic system soybean-stink bug-egg parasitoids
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
Life history and immature stages of Chlamydastis platyspora (Elachistidae)
Volume: 58Start Page: 75End Page: 7
Seasonality of vespid species (Hymenoptera: Vespidae) in a central Brazilian cerrado
Foraging habitats as well as the tluctuations in vespid species' abundance in Mato Grosso State, Brazil, were deterrnined,t hrough sampling effon per hour per collector in four cerrado sensu lato habitats," campo úmido" (Cu)," campo sujo" (es), "cerrado sensu stricto" (Css), and "gallery forest" (Mg), during four periods consisting of two dry (August 1988 and June 1989) and two wet (October and December 1988) season periods. For "campo úmido", sorne species seern to be highly seasonal, either in the dry or wet seasons, whereas very few species occur year-round. The abundance, species composition and richness varied between habitats types and between seasonsForaging habitats as well as the tluctuations in vespid species' abundance in Mato Grosso State, Brazil, were deterrnined,t hrough sampling effon per hour per collector in four cerrado sensu lato habitats," campo úmido" (Cu)," campo sujo" (es), "cerrado sensu stricto" (Css), and "gallery forest" (Mg), during four periods consisting of two dry (August 1988 and June 1989) and two wet (October and December 1988) season periods. For "campo úmido", sorne species seern to be highly seasonal, either in the dry or wet seasons, whereas very few species occur year-round. The abundance, species composition and richness varied between habitats types and between season
Seasonality of vespid species (Hymenoptera: Vespidae) in a central Brazilian cerrado
Foraging habitats as well as the fluctuations in vespid species abundance in Mato Grosso State, Brazil, were determined, through sampling effort per hour per collector in four cerrado sensu lato habitats, "campo úmido" (Cu), "campo sujo" (Cs), "cerrado sensu stricto" (Css), and "gallery forest" (Mg), during four periods consisting of two dry (August 1988 and June 1989) and two wet (October and December 1988) season periods. For "campo úmido", some species seem to be highly seasonal, either in the dry or wet seasons, whereas very few species occur year-round. The abundance, species composition and richness varied between habitats types and between seasons