Life history traits and population growth of Encarsia formosa Gahan (Hymenoptera: Aphelinidae) local population from Serbia

Abstract

Life history traits (longevity, development time, parasitism rate and adult emergence) and population growth (instantaneous rate of increase) of six local populations of the parasitoid wasp Encarsia formosa Gahan, 1924, from several regions in Serbia (without a tradition in using commercial strains of the parasitoid for biological control of greenhouse whitefly) and the Dutch strain (D) were investigated in laboratory bioassays. The populations were reared on tobacco plants infested with greenhouse whiteflies Trialeurodes vaporariorum Westwood. The data acquired in the present study show that females of the local E. formosa population Bujanovac (B) showed most promising results for integrated control of whitefly in Serbia, with regard to their longevity and reproductive potential; the females B had the highest values of adult longevity in host absence (20.65 days), adult longevity in host presence (12.45 days), total parasitism (199.53 pupae/female), adult emergence (171.18 adults/female) and instantaneous rate of increase (0.240-0.303 day(-1)). The life history traits of females B were significantly different from those of females in all other studied populations, except population D, for all parameters except longevity in host presence, and population Svilajnac (S), but only for adult longevity. Population S had the longest development time (15.70 days), significantly longer than all other populations (14.00-14.67 days), except population Zemun (Z) with 15.16 days. The females of local populations B, S, and the commercial population D had higher survivorship than those of the other four studied local populations. Our experiment provided initial data for further assessment of local populations of this parasitoid wasp as a biological agent to be used in control of greenhouse whiteflies in Serbia.