Data from: Neonicotinoid insecticides serve as inadvertent insect contraceptives

There is clear evidence for sublethal effects of neonicotinoid pesticides on non-target ecosystem service providing insects. However, their possible impact on male insect reproduction is currently unknown, despite the key role of sex. Here, we show that two neonicotinoids (4.5 ppb thiamethoxam and 1.5 ppb clothianidin) significantly reduce reproductive capacity of male honey bees (drones), Apis mellifera. Drones were obtained from colonies exposed to the neonicotinoid pesticides or controls, and subsequently maintained in laboratory cages until they sexual matured. While no significant effects were observed for male teneral body mass and sperm quantity, the data clearly showed reduced drone lifespan, as well as reduced sperm viability (proportion living vs. dead) and living sperm quantity. Our results demonstrate for the first time that neonicotinoid pesticides can negatively affect male insect reproductive capacity, and provide a possible mechanistic explanation for managed honey bee queen failure and wild insect pollinator declines. The widespread prophylactic use of neonicotinoids may have previously overlooked contraceptive effects on non-target insects, thereby limiting conservation efforts.