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.
