The U.S. Fish and Wildlife Service’s (FWS) nationwide final biological opinion (BiOp) for Malathion has prompted EPA to take steps to protect a number of endangered species that were identified as being threatened by the insecticide. Malathion is an organophosphate insecticide use on a wide variety of food and non-food crops to kill insects systemically and on contact. It is also used as a mosquito adulticide. The BiOp was prompted after EPA released a biological evaluation on malathion in January 2017EPA’s evaluation found the insecticide was likely to affect both aquatic and terrestrial animals by inhibiting and enzyme necessary for synapse and neuromuscular function, leading to sublethal effects and mortality.
FWS collaborated with EPA and the malathion technical registrants to create the BiOp. The BiOp also includes information provided by stakeholders, non-governmental organization, and members of the public who commented on EPA’s initial evaluation. The BiOp states that malathion is likely to jeopardize 78 different species and destroy or adversely affect 23 habitats. FWS proposed mitigation measures that would reduce the application rates, create no spray zones, and apply label changes for the pesticide users to follow. One proposed mitigation measure for reducing the application rates would restrict application when rain is predicted and when certain types of crops are in bloom. The purpose of these mitigation measures is to minimize the likelihood of exposure to different species and reduce the affects to their development and habitats.
The BiOp states specific measures and mandatory label instructions will be available through EPA’s Bulletins Live! Two website, which provides information on endangered species, along with other relevant information. Registrants were asked to submit amended labels to EPA by June 29, 2022.