Biological control of bruchid Callosobruchus maculatus (F.) in blackgram

Abstract

Pulse beetle, Callosobruchus maculatus (F.) (Bruchidae: Coleoptera) is a major pest of stored blackgram, greengram, cowpea and other pulse grains. Nnatural incidence of bruchid parasitoid Dinarmus sp. (Pteromalidae: Hymenoptera) have been recorded in the stored blackgram seeds and also at field level. 500 blackgram seeds were released with 2 pairs of fresh bruchid adults in 5 different sets (A to E) with three replications. Two pairs of freshly emerged adult parasitoids were released at 5, 10, 15 and 20 days (A to D) after bruchid inoculation. A set of control (E) was maintained with no parasitoid release. Among the treatments, parasitoid released on 5th and 10th day had more adult parasitoid emergence (9.0 and 11.0) in the first generation and bruchid adult emergence was low (3.0 and 2.0) in the treatments. The parasitoid and bruchids were allowed up to four generations in the same set of seeds. The adult parasitoid emergence was the highest in second generation and in subsequent generation the emergence of parasitoid and bruchid was the least. After second generation the seeds were totally damaged in the control. The mass culturing techniques of the parasitoid and the feasibility for large scale release to control bruchids to be studied in future. © JBiopest.