Realized heritability of resistance to dicrotophos in greenhouse whitefly

Realized heritability ( h 2 ) of resistance to dicrotophos in greenhouse whitefly, Trialeurodes vaporariorum Westwood, was estimated from a laboratory selection experiment. Five generations of selection increased the LC 50 approximately 13‐fold. Estimated h 2 of resistance to dicrotophos was 0.40 when calculated with the method of Tabashnik (1992) and 0.35 with the method of Tanaka & Noppun (1989). These results suggest that 35 to 40% of the total phenotypic variation in resistance was caused by additive genetic variation. For thirteen previously reported estimates of h 2 of insecticide resistance in other insect pests, the mean was 0.29. The relatively high h 2 of dicrotophos resistance for T. vaporariorum is consistent with rapid resistance development in field populations.