Bioactivity of Croton blanchetianus Baill (Euphorbiaceae) essential oil on the Callosobruchus maculatus Fabricius, 1775 (Coleoptera: Chrysomelidae)

Abstract

The toxicity was calculated by contact, the oviposition and emergence rate of C. maculatus on cowpea treated with the essential oil of Croton blanchetianus and the residual effect in different periods of storage, and additionally the lethal concentrations (CL50 and CL90) were determined. The contact toxicity test and order to the oviposition and emergence rates of C. maculatus was carried out in Petri dishes, using 6 concentrations (0, 2.5, 5, 7.5, 10 and 12.5 μL/20g). In the residual test, the cowpeas were submitted to different storage periods (0, 30 and 60 days). The results showed that the C. blanchetianus essential oil showed contact toxicity on the beetle C. maculatus. It was observed that lethal concentrations were considered low. This oil also reduced oviposition and emergence of adults. On the other hand, during different periods of storage the oil's action diminished, presenting potential to be used in management programs of C. maculatus in stored beans.