D3097: Investigating the compatibility of insecticide applications with natural enemies for the suppression of alfalfa pests

The alfalfa weevil (Hypera postica Gylenhall) and a complex of aphids including the pea aphid (Acyrthosiphon pisum Harris) and blue alfalfa aphid (Acyrthosiphon kondoi L.) are considered the most serious pests in alfalfa production and are routinely managed using insecticides. However, the reduced number of insecticide-active ingredients and their overuse has led to evidence of insecticide resistance for alfalfa weevil and aphids. Moreover, these broad-spectrum insecticides also can harm natural enemy communities, which are known to provide an important ecosystem service of natural pest suppression. What is unclear is how the transition to newer insecticide classes will impact the conservation of natural enemy communities and their phenology. Therefore, this project aims to evaluate the impact of current and new insecticide modes of action used for alfalfa pests on natural enemy diversity and phenology, and their ability to suppress pest populations. Our findings will help growers to manage alfalfa pests effectively with a lower environmental cost, reducing insecticide resistance risk and protecting beneficial insects.