Recruitment of the Red Imported Fire Ant, Solenopsis Invicta, to Soybean Oil Baits

Abstract

A field investigation was conducted to compare the diel periodicity and rates of recruitment of the red imported fire ant, Solenopsis invicta Buren, to soybean oil presented in two forms. Bimodal patterns of recruitment were usually observed to corn cob particulates saturated with oil but not to cotton wicks saturated with oil. Recruitment to both rates was usually higher at night but not always significantly ($P @? 0.05$) different from rates observed during the day. Significantly ($P @? 0.05$) higher rates of recruitment occurred to the particulate oil bait relative to the liquid oil bait at most times studied. The size of ants recruited to the two baits varied significantly ($P @? 0.05$); however, no consistent or explainable pattern in the size of ants recruited over each 24-hour period was observed for either bait. Ants of the media worker subcaste were generally recruited at significantly ($P @? 0.05$) greater rates to both baits relative to minor and major workers. Standard multiple regression analyses revealed that changes in air and soil temperatures had a significant ($P @? 0.05$) impact on recruitment; however, changes in air and soil moisture did not appear to influence rates of recruitment to the baits.