RESUMO O uso de inseticidas não seletivos na produção agrícola pode reduzir ou eliminar agentes biológicos que regulam os insetos indesejáveis para o homem no processo produtivo. Neste estudo, o efeito da toxicidade de produtos sintéticos foi avaliado para o parasitoide Encarsia hispida tendo como hospedeiro a mosca-branca, Bemisia tabaci biótipo B, em algodoeiro. O estudo foi realizado através do uso de bioensaios, usando-se delineamento inteiramente casualizado em esquema fatorial. Nos bioensaios foram utilizadas pupas e adultos de E. hispida, as quais foram submetidas à pulverização com os seguintes produtos químicos: tiametoxam, deltametrina, imidacloprido e piriproxifem, nas proporções de 1,0 g L-1, 1,0 mL L-1, 4,0 mL L-1 e 2,5 mL L-1, respectivamente, e um tratamento controle (água destilada). Foram utilizadas pupas com 1 e 3 dias de idade para exposição tópica, mediante aplicação na região dorsal do tegumento. Nos adultos do parasitoide, com idade de 1 e 15 dias de emergência, foram utilizados um bioensaio de contato residual para determinação da toxicidade dos inseticidas. Os inseticidas tiametoxam e imidacloprido são inócuos ao estágio de pupa, no entanto, os mesmos são nocivos à fase adulta de E. hispida. Os inseticidas deltametrina e piriproxifem são nocivos para ambas fases pupal e adulta de E. hispida. | ABSTRACT The use of non-selective insecticides in agricultural production can reduce or eliminate biological agents that regulate insects that are undesirable to humans in production processes. Here, the toxicity of synthetic products on the parasitoid Encarsia hispida was evaluated, the host of which is the whitefly, Bemisia tabaci biotype B, found on cotton plants. The study was carried out using bioassays, in a completely randomized design in a factorial scheme. Pupae and adults of E. hispida were used in the bioassays, which had been sprayed with various chemicals (thiamethoxam, deltamethrin, imidacloprid, and pyriproxyfen) at different concentrations (1.0 g L-1, 1.0 mL L-1, 4.0 mL L-1, and 2.5 mL L-1). The control treatment was distilled water. Chemicals were topically placed in the dorsal region of the tegument of 1 and 3-day old pupae. Then, between 1 and 15-days of emergence of adult parasitoids, residual contact bioassay were used to determine the toxicity of the insecticides. The insecticides thiamethoxam and imidacloprid were harmless to the pupal stage of E. hispida, but were harmful to the adult stage. The insecticides deltamethrin and pyriproxyfen were harmful to both pupal and adult stages of E. hispida.

ABSTRACT The aim of this study is to document the heretofore unrecorded natural occurrence of the larval parasitoid Digonogastra sp. on Diatraea flavipennella Box, 1931 (Lepidoptera: Crambidae) in sugarcane fields. The collections were made in the Usina Santa Clotilde area, in Rio Largo municipality, Alagoas State, Brazil. This is the first record of Digonogastra sp. parasitizing caterpillar of D. flavipennella in Brazil. The parasitism rate was found to be 14.06%. The occurrence of this parasitoid indicates potential for natural regulation of that pest in sugarcane crop. | RESUMO O objetivo deste estudo foi registrar a ocorrência natural do parasitoide larval Digonogastra sp. em Diatraea flavipennella Box, 1931 (Lepidoptera: Crambidae) em cana-de-açúcar. As coletas foram realizadas na Usina Santa Clotilde (9º25’S, 35º49’W, 127m de altitude), no município de Rio Largo, Estado de Alagoas, Brasil. Este é o primeiro registro do gênero Digonogastra parasitando lagartas de D. flavipennella no Brasil. A taxa de parasitismo verificada foi de 14,06%. A ocorrência deste parasitoide indica um potencial de regulação natural da referida praga em cana-de-açúcar.

ABSTRACT Chalcididae is a family of parasitoids with wide distribution and great richness, with almost 1,500 described species. Its diversity might be greater than that known today, mainly due to the few existing studies and its taxonomic complexity. Studies in semiarid regions are scarce and necessary to contribute to the biogeographic knowledge of the neotropical fauna. Therefore, the objective of this work was to record Chalcididae species that occur in the municipality of Barra do Choça, in the Semiarid region of the state of Bahia, Brazil. Five Malaise traps were distributed in two areas with native vegetation and an area with eucalyptus plantation, which were monitored monthly for two consecutive years. The insects were sorted and specimens of the family Chalcididae were identified at the species level, when possible. A total of 182 specimens from five genera (Aspirrhina Kyrbi, 1883; Brachymeria Westwood, 1829; Conura Spinola, 1837; Dirhinus Dalman, 1818, and Haltichella Spinola, 1811), and 18 species were identified and 32 were morphotyped. The genus Conura was the most abundant and the most diverse, with 12 species identified and 30 potential new species. The native vegetation presented higher abundance and higher taxonomic wealth, mainly in the area at initial stage of succession (capoeira). The eucalyptus area presented low diversity, with predominance of Brachymeria species. The species C. nigricornis presented the highest relative frequency. This study constitutes the first list of Chalcididae species in the Semiarid region of Brazil. The sampling carried out in the state Bahia showed an important diversity of Chalcididae species when compared to other regions of Brazil.