Impacts of reduced risk pesticides on four life stages of Hippodamia convergens

Reduced risk pesticides are designed to lower human and environmental health risks, however their effects on natural enemy populations are not yet known.  In order to determine their impact on Hippodamia convergens, seven pesticides were tested (Altacor, Cyazypyr, Delegate, Kocide-Manzate, Kumulus, Rimon, and Warrior).   Eggs and pupae were directly exposed to pesticide, while larvae and adults were exposed via three different routes, simultaneously: oral, residual, and direct.  For eggs, the majority of pesticides did not impact hatch rates, with the exception of the insect growth regulator, Rimon (14% survivorship).  For larvae, pesticides lowered survivorship to less than 50%, except for Kocide-Manzate (84%).  Adult survivorship remained comparable to controls, however fertility for adults exposed to Rimon was significantly lowered (1.0%).  For all life stages, the broad spectrum pyrethroid, Warrior, reduced survivorship to nearly 0%.  Overall, these results indicate that impacts vary according to the type of pesticide used and the particular life stage exposed.  Such data may be used to inform conservation of natural enemies and improve pest management decisions.