اثرات کشندگی و غیرکشندگی چند حشره‌کش روی زنبور Trichogramma brassicae در تخم های Tuta absoluta

Abstract
Tomato leaf miner Tuta absoluta is one of the most important pests of tomatoes in Iran which first reported at 2009. This pest has evolved resistance to many registered insecticides. Biological control as a promising alternative may be can use as a single strategy or be integrated to chemical control. Biological control agents may have some incompatibility with insecticides. Then selection of proper dose, time and spraying method are essential. In this study lethal effect of chlorantraniliprole, spinosad, abamectin and indoxacarb were evaluated on Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) immature exposed within Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) eggs. On the other hand, sublethal effects of LC25 of these insecticides on T. absoluta eggs and LC50 of Metarhizium anisopliae (Metschn.) Sorokin (Moniliales: Moniliaceae) were assessed on life table parameters of T. brassicae. There is a lack of knowledge in this course in Iran. In this study, different larval instars of T. absoluta were collected from a damaged tomato field in Bilasuvar county, Ardabil province and moved to a greenhouse of the Department of Plant Protection, University of Tabriz. The larvae were nurtured by foliage of greenhouse grown tomato plants to obtain adults. Then it was let them to feed, mate and lay their eggs on plants for 24 hours. Twenty four hour old eggs were used in bioassays. The insecticides and entomopathogen fungus were sprayed on parasitized and non-parasitized eggs by using a Potter spray tower. The fate of the hatched eggs was followed up to death and all events were recorded daily. Life table parameters including gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), generation time (T), doubling time (DT), intrinsic birth rate (b) and intrinsic death rate (d), were estimated according to Carey (1993). Variance of the parameters was estimated using Jackknife pseudovalues. Tukey's multiple range test (P ≤ 0.05) was used to compare the means of the treatments. The LC50 value of chlorantraniliprole was the lowest among the insecticides, so it was the most deleterious insecticide on this parasitoid. On the other hand, indoxacarb had the most detrimental effects on T. brassicae life table parameters. The entomopathogenic M. anisopliae had minor, sometimes non-significant effects compared to control.