Laboratory evaluation of the potential efficacy of bacillus thuringiensis israelensis for the control of mosquitoes in malaysia
Laboratory evaluation of the potential efficacy of bacillus thuringiensis israelensis for the control of mosquitoes in malaysia
Lee, H.L.; Cheong, W.H.
Tropical Biomedicine 2(2): 133-138
1985
Laboratory bioassays of Bacillus thuringiensis israelensis (Bti) (IPS-78 standard powder) were conducted against late 3rd/early 4th instar larvae of Aedes aegypti, Ae. albopictus, Ae. togoi, Culex quinquefasciatus, Armigeres durhami, Anopheles balabacensis and Chironomus species. Both Ae. aegypti and Ae. albopictus were highly sensitive to Bti, but very high LC50 and LC90 values were obtained for Chironomus species. The potency of Bti was reduced in alkaline water (pH 10), but no reduction in activity was observed in NaCl solutions of up to 0.5%. Bti powder in suspension settled to the bottom of a 45.0 cm column of water in 3 hours after standing. No toxic effects on the guppy were observed. High Bti selection pressure on Ae. aegypti larvae failed to produce a Bti resistance strain in 8 generations.