Development of a lateral flow immunoassay for rapid field detection of the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae).

The red imported fire ant, Solenopsis invicta, is an aggressive, highly invasive pest ant species from South America that has been introduced into North America, Asia, and Australia. Quarantine efforts have been imposed in the USA to minimize further spread of the ant. To aid the quarantine efforts, there remains an acute need for a rapid, field portable method for the identification of these ants. In this report, we describe two novel monoclonal antibodies that specifically bind the S. invicta venom protein 2 produced by S. invicta. Using these monoclonal antibodies we developed a lateral flow immunoassay that provides a rapid and portable method for the identification of S. invicta ants. The lateral flow immunoassay was validated against purified S. invicta venom protein 2 and 33 unique ant species (representing 15 % of the total species and 42 % of the Myrmicinae genera found in Florida), and only S. invicta and the S. invicta/richteri hybrid produced a positive result. These monoclonal antibodies were selective to S. invicta venom protein 2 and did not bind to proteins from congeners (i.e., S. geminata or S. richteri) known to produce a S. invicta venom protein 2 ortholog. This S. invicta lateral flow immunoassay provides a new tool for regulatory agencies in the USA to enforce quarantine protocols and limit the spread of this invasive ant. Graphical Abstract Field method to detect and identify the red imported fire ant, Solenopsis invicta.