The Effects of Three Acaricides on Egg Hatchability of Three Populations of the Two-Spotted Spider Mite Tetranychus urticae Koch (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) in all of the irrigated and arid regions either in Jordan and most countries in the world is considered to be a destructive pest all the year around. However, laboratory bioassays were conducted to evaluate the effects of chemical compounds on egg hatchability of the two-spotted spider mite, after treatment of egg stage of Syria, Baq'a and Deir-Alla populations in three successive generations against three acaricides selected from different groups. Mite eggs laid on bean leaves were separately treated with LC50 acaricides' concentrations. The percentages of the eggs that survived after hexythiazox treatments of the females were increased from the first generation up to third generation for Deir-Alla and Baq'a populations. The two field populations treated with hexythiazox had a significant effect on the egg hatching for the three generations. Etoxazole and clofentezine acaricides have a significant decrease of three different populations. Etoxazole had high toxicity to the spider mite eggs since it has a sterilizing effect on the adult female.