Transfer of pyriproxyfen to nectar sources and insect pollinators associated with autodissemination approaches used for mosquito control

Autodissemination is a method of pesticide self-delivery, which is premised on the use of insects as the delivery agent. This method has recently attracted attention for mosquito control, particularly to target container breeding species such as Aedes aegypti and Aedes albopictus. The intended goal and appeal of autodissemination approaches are that small amounts of a highly potent IGR are delivered to cryptic mosquito breeding sites. Current field studies suggest that these strategies can be successful in reducing mosquito populations. However, while direct targeting of cryptic locations seems like a significant advantage over large-scale applications of insecticides, this could be more harmful to non-target organisms by delivering these highly potent long-lasting growth inhibitors to the exact places that other beneficial insects visit, such as nectar sources. Here we discuss experiments that examined for non-specific transfer of pyriproxyfen (PPF) to artificial nectar sources, honey bees, and painted lady butterflies associated with the use of autodissemination approaches. Data suggests male Ae. albopictus dusted with PPF deliver non-lethal doses to artificial nectar sources and insect pollinators. However, exposure to non-lethal doses by mosquitoes may improve the success of autodissemination approaches. The results are discussed in the context that with any pesticidal approach, there are risks to non-target organisms and the risk may be acceptable in times of mosquito control need, particularly in association with disease outbreaks. However, it’s important to understand the level of risk to non-targets and not assume any effects are negligible because PPF is used in small amounts.