Co-Authors:
Wysoki, M., Department of Entomology, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
De Haan, P., Laboratory of Experimental Entomology, University of Amsterdam, Amsterdam, Netherlands
Izhar, Y., Extension Service, Ministry of Agriculture, Ha Qirya, Tel Aviv, Israel
Abstract:
The activity of Toarow CT, a commercial preparation containing dead spores of Bacillus thuringiensis var. kurstaki, was compared with that of two other commercial preparations containing live spores, against the giant looper, Boarmia (Ascotis) selenaria (Schiffermüller), and the honeydew moth, Cryptoblabes gnidiella (Millière). In laboratory experiments Toarow CT was compared with Dipel W.P. and in field trials with Thuricide HP. In laboratory trials 60-80% of B. selenaria larvae aged 8 and 15 days were killed by a product concentration of 0 · 5% and 80-90% by a concentration of 1%, respectively, for Toarow CT and Dipel WP; 100% mortality of 15-day-old giant looper was reached only on the ninth day after initial treatment. In field trials, after 1 week some larvae remained in Toarow CT-treated plots, but after 2 weeks no live larvae were found after Toarow CT and Thuricide HP treatments. Because of the great sensitivity of C. gnidiella to B. thuringiensis preparations, the 6- to 8-day-old larvae were killed on avocado fruit and on artificial medium, between 24 h and 4 days after treatment, depending on their age and the concentration of preparations used. © 1988.