The effects of some pesticides on fecundity and lifespan of Panonychus ulmi (Koch) and Neoseiulus californicus (Mc Gregor): hormoligosis

Farmers generally prefer to use chemical control methods against many of diseases, pests and weeds that cause economic losses in agricultural production. There are disadvantages of pesticides used in the control of pest, they disrupt the natural balance, causing directly or indirectly poisoning of people and animals, they have harmful effects on natural enemies which result in increase in pest populations and hormoligosis. Sublethal doses of some pesticides result in increase of the fecundity in insects and mites. This is called hormoligosis. In this study, the effect of some pesticides commonly used in apple orchards was investigated on the reproductive rate and lifespan of European red mite (Panonychus ulmi Koch.) (Acari: Tetranychidae) that is one of the main pests and predator mites Neoseiulus californicus (Mc Gregor) (Acari: Phytoseiidae). Pesticides were directly applied by sprey tower on 0-24 hours larvae of both mite that is on the leafs (plum or beans) on wet cotton in the Petri dish with spray tower. The average lifespan (larvae+nymphs+adults) of P. ulmi larvae exposed to distilled water (control), cypermethrin, imidacloprid, deltamethrin, spirodiclofen + abamectin and thiacloprid was found to be 25.50, 24.92, 23.97, 23.77, 21.60, 23.85 days, respectively. The average lifespan of N. californicus larvae exposed to control and same insecticides was detected to be 27.72, 26.94, 25.40, 27.94, 25.71, 26.88 days, respectively. The average number eggs of P. ulmi larvae exposed to same experimental-conditions was 33.79, 35.15, 37.62, 36.17, 33.95, 36.75 eggs/female. The average oviposition for N. californicus larvae exposed to control and same insecticides was determined to be 36.03, 46.44, 47.46, 46.43, 35.43, 42.38 eggs/female. Except for abamectin + spirodiclofen, other pesticides caused a limited increase of eggs in individually female P. ulmi while they caused a greater increase of egg predatory mite, N. californicus.