Abstract
The strain IfB01 of Isaria fumosorosea (Paecilomyces fumosoroseus) is a promising myco-insecticide candidate for control of Bemisia tabaci. Joint action of strain IfB01 and four chemical insecticides [spirotetramat (Spi), acetamiprid (Ace), imidacloprid (Imi) and thiamethoxam (Thi)] against the whitefly B. tabaci was evaluated using the cooperative virulence index (c.f.). Substantial synergistic actions were found in the mixtures of IfB01 conidia with Spi, Imi and Thi 2–4 days after treatment. The greatest synergism was recorded in the mixture of IfB01 (2.5 × 106 conidia/L) and Imi (12.5 mg/L), which had a c.f. value of 184 at day 3 after treatment. Furthermore, the shorter LT50 values recorded in mixtures indicated that effectiveness improved when the conidia were applied with the chemical insecticides. However, no substantial synergisms were recorded with Ace and from day 5 onwards.
Acknowledgements
This research was supported by the National Department of Public Benefit Research Foundation (201003065).