Multiplexed lateral flow immunoassay to discriminate Solenopsis invicta, Solenopsis richteri, and Solenopsis invicta × richteri hybrids

Solenopsis invicta and Solenopsis richteri are aggressive, highly invasive ant species from South America that were introduced into North America in the early part of the twentieth century. Biosecurity efforts in the US included the establishment of a quarantine to minimize the human-assisted spread of these ants. A limitation of the quarantine is rapid identification/discrimination of these ants when found entering non-quarantined areas. Using monoclonal antibodies designed toward S. invicta and S. richteri venom protein 2, we developed a multiplexed lateral flow immunoassay that provides a rapid and portable method for the identification of S. invicta, S. richteri, and the S. invicta × richteri hybrid. The multiplexed lateral flow immunoassay was validated against 39 unique ant species, and only S. invicta, S. richteri, and the S. invicta × richteri hybrid were detected. The assay did not detect proteins from the congener S. geminata known to produce a S. invicta venom protein 2 ortholog. The invasive fire ant multiplexed lateral flow immunoassay provides a new tool for regulatory agencies in the US to enforce quarantine protocols and limit the spread of these invasive ants.