Biological control against Bemisia tabaci
An integrated pest management programme against Bemisia tabaci (EPPO A2 quarantine pest) has been tested on Poinsettia (Euphorbia pulcherrima) and Hibiscus grown in a commercial glasshouse in Florida (US). The main component of the program was the use of an entomogenous fungus Paecilomyces fumosoroseus which was applied as a conidial suspension (1.0 x 107 conidia per ml). The strain used (PFR 97), recently isolated in Florida, has been found highly virulent against B. tabaci. The following applications were made: dipping of cuttings and drenching of pots during the propagation stage and three foliar treatments in the production greenhouse (at 5 to 7 day-intervals) followed by additional treatments if the threshold level of one adult per plant was exceeded. Every week, plants were inspected and whitefly populations were estimated. The IPM programme was compared with a conventional chemical programme. The authors concluded that the final quality of plants protected with P. fumosoroseus was fully comparable with the quality of plants protected by chemicals, and noted that in order to suppress the population density of B. tabaci equally, respectively 18 and 21 insecticide treatments were needed to protect Poinsettia and Hibiscus.
Sources
Osborne, L.S.; Landa, Z. (1994) Utilization of entomogenous fungus Paecilomyces fumosoroseus against sweetpotato whitefly, Bemisia tabaci.
IOBC WPRS Bulletin, 17 (3), 201-206.