Effect of Insecticides on the Longevity of Apis mellifera L. (Hymenoptera: Apidae)
Hafiz Khurram Shurjeel1, Muhammad Anjum Aqueel2, Ejaz Ashraf3*, Asad Ali4 and Arooba Rubab5
Honey bee Apis mellifera L., are good crop pollinators, however, its population is decreased over the years due to various factors including spraying chemical insecticides for pest management. The present experiment was therefore, designed to look for the effect of some new insecticides (cyhalothrin, nitenpyram, emamectin benzoate) applied at flowering stage of sunflower (variety Hysun-33). After three days of pesticides application, Apis mellifera was exposed to insecticides, placing three honey bee colonies in the center of each plot in the field. Four frames from each colony and twenty cells from each frame were selected as samples for further studies. After egg hatching larval duration was recorded until pupal duration starts. The honey bees were caged after pupal duration starts and marked with permanent marker for adult data recording. The data was recorded daily for 30 days. The effects of different chemical insecticides (nitenpyram @75ml/acre- new chemistry, cyhalothrin; nok-out @200ml/ acre, tycon; emamectin benzoate @ 200ml/acre) on egg presence, egg hatching, larval duration, pupal period and adult longevity were examined. Results revealed that the nitenpyram was found statistically significant which means it was affecting the following stages in honey bees; eggs presence (less number of eggs) df=3, F=8.97, P=<.001, egg hatching (less number of eggs hatched) df=3, f=11.94, p <.001, day to pupation (F=3, df = 5.611, p< 0.001) and less adult emergence rates in the selected cell. The cyhalothrin was also found statistically significant and affecting the honey bees at egg hatching (decreased egg hatching as compared to control) and pupation (less pupation as compared to the control) stages and less toxic at day to adult emergence and day to pupation. While the emamectin benzoate was found affecting on egg hatching with average (0.71) and at pupation rate with average (0.86). The knowledge from this study describes the effects of chemical compounds on honey bees and potentially facilitates beekeeping farmers to avoid the use of chemical compounds for their colonies to reduce colony problems.