Reproduction and development of Eretmocerus eremicus (Hymenoptera: Aphelinidae) on Trialeurodes vaporariorum (Homoptera: Aleyrodidae)

摘要

Eretmocerus eremicus is the most abundant parasitoid of the Bemisio complex in North America, k can parasitize equally successfully the most common whiteflies in greenhouses, Trialeurodes vaporariorum and the Bemisio complex. The parasitoid is used inEurope for whitefly control, either alone or in combination with releases of Encarsia formosa. Life-cycle and demographic parameters of this parasitoid were evaluated using T. vaporariorum as a host. Fecundity, developmental time, juvenile mortality, sex ratio and longevity were determined under laboratory conditions (25 ± I °C, 50-60% RH, 12:12 (L:D) h photoperiod) to be able to calculate the intrinsic rate of natural increase of the parasitoid on tomato plants, cultivars Moneymaker and Hayslip. Thelife-cycle parameters of the parasitoid did not differ significantly on the two tomato cultivars. The mean fecundity of E. eremicus was 162 ± 20 (mean ± s.e.) eggs on Moneymaker and 167 + 20 eggs on Hayslip tomato cultivar. The developmental time was22 ± 0.04 days, the juvenile mortality was 7% and the sex ratio was close to 1:1. Adult longevity was 14 ± 1.35 days. Life-cycle parameters indicate that the net reproduction (Ro) was 91 and 86. the mean generation time (Tt) was 28 and 27, and the intrinsic rate of natural increase (rm) was 0.161 and 0.165 on the cultivars Moneymaker and Hayslip, respectively. The r_m ranges among the r_m's registered for other parasitoids used to control Bemisio sp. and Trialeurodes sp. Thus, E. eremicus seems a goodcandidate for biological contro) of two of the most important whitefly pests in greenhouses.