Abstract

Using pesticides with less side-effects on predators can be helpful in success of integrated pest control. We studied effects of the least recommended doses of two pesticides, spirodiclofen and azadirachtin (0.18 and 0.3 µl/ml, respectively) on some biological traits and predation of Neuseiulus californicus. In first experiment the same-aged eggs of the predator were individually transferred on bean leaves and then were dipped in pesticide dilutions. Hatchability of the eggs was recorded. In the second experiment adult females were transferred into closable glass cages dipped in pesticide dilutions and supplied with sufficient immature stages of two -spotted spider mite as food. Survival and oviposition were checked for 13 days. Also, predation rate was recorded for 10 days. 100 and 99.07 percent of the treated eggs were hatched in azadirachtin and spirodiclofen treatments, respectively. Females’ adult longevity showed significant decrease in both pesticide treatments (7.80, 12.39 and 17.51 in azadirachtin, spirodiclofen and control respectively). Mean number of egg s produced per female were 0.83 and 0.55 in spirodiclofen and azadirachtin treatments, respectively. Azadirachtin caused 82.5 percent mortality while the mortality caused by spirodiclofen was 51.3 percent after 13 days. Mean daily consumption by females were 9.63 and 12.38 prey in spirodiclofen and azadirachtin treatments, respectively. Overall, it seems these pesticides do not have significant adverse effects on the predatory mite and especially spirodiclofen could be used in IPM programs. Keywords: Biological control, Predatory mite, Side-effects, Reproduction