Biological and biochemical effects of chronic exposure to very low levels of dietary cypermethrin (Cymbush) on honeybee colonies (Hymenoptera: Apidae).

Cymbush (100 g of pure cypermethrin/liter of petroleum ether) was added to sucrose syrup at 12.5 microg/L and given to honeybee colonies (Apis mellifera mellifera, L.) in their diet for 5 months (July to November). Many perturbations have been recorded in treated groups in contrast to controls placed in the same area. Mortality in the hive, bee behavior, brood areas, supersedure, glucosemia, trehalosemia, and (Na+,K+)ATPase activity are many factors significantly affected over the 18-week test following sublethal treatment. Results suggested that long-term exposure of honeybees to cypermethrin-contaminated diets at concentrations not immediately lethal to worker adults may cause significant hidden damage to colonies.