Biologia comparada de eulofídeos criados em pupa de Spodoptera cosmioides (Walker, 1858) (Lepidoptera: Noctuidae)

Abstract

Trichospilus diatraeae and Tetrastichus howardi (Hymenoptera: Eulophidae) are parasitoids used in the biological control of insect pests. Spodoptera cosmioides (Lepidoptera: Noctuidae), a common pest in several crops, has raised interest regarding the use of biological control agents to manage its population in the field, as well as its potential use as an alternative host for parasitoid rearing. This study aimed to compare the biological characteristics of T. howardi and T. diatraeae raised on S. cosmioides pupae. The experiment was conducted under controlled conditions (25 ± 1 °C, 70 ± 10% RH, and 14-hour photophase), using pupae aged 24 to 48 hours, which were individually placed in glass tubes (15 × 1 cm) and exposed to parasitoid females for 24 hours. The parameters evaluated were: parasitism rate (%), emergence rate (%), life cycle duration, progeny, sex ratio, and longevity of both males and females. A completely randomized design (CRD) was used, with two treatments, being them, S. cosmioides pupae exposed to T. diatraeae or T. howardi, with 10 replicates of 5 pupaes per species. T. diatraeae showed a high parasitism rate (94%) but no adult emergence, while T. howardi had a low parasitism rate (8%) but a 75% emergence rate from parasitized pupae, with an average of 46 offspring per host. The results indicate that both species recognize S. cosmioides as a host but present developmental limitations highlighting the need for further studies using different female densities per pupa.