The biology of Earias vittella (Fabricius) and Earias insulana (Boisd)(Lepidoptera-Noctuidae ) and their biological control by Bacillus thuringiensis, Berliner.

Abstract

The experimental work was conducted during the period of March–September (2005) in the laboratories of the College of Agricultural Studies Shambat of Sudan University of Science and Technology to study the life cycle of two species of the Egyptian bollworm Earias insulana (Boisd) and Earias vittella (F.), and to assess the effect of three concentrations of Bacillus thuringiensis (4, 7, and 10 gm/l) on the larvae. The design of the experiment was the Complete Randomized Block with four replicates. The life cycle studies showed that the two species Earias inuslana (Boisd) and Earias vittella (F.) completed development in 32.1 ± 4.6 and 31.1 ± 5.2 days respectively under the laboratory conditions (temp. 26 ± 3°C & RH 42%). Treatment of the 1st instar larvae in the 2 species with Bacillus thuringiensis (Agerin®) gave a very high mortality (93-100%). The few individuals which survived gave small size adults when compared with adults of untreated control.