Semiochemicals that disrupt foraging by the Argentine ant (Hymenoptera: Formicidae): Laboratory bioassays

Two different laboratory bioassays were developed to quantitatively determine the repellent activity of semiochemicals, such as farnesol and methyl eugenol, against the Argentine ant, Iridomyrmex humilis (Mayr). One assay, based on the ability of ants to cross barriers of beeswax containing different concentrations of test chemicals, was not designed to discriminate between olfactory or gustatory modes of detection, The other was based on the ability of an ant to detect airborne chemicals and, therefore, measured only the olfactory response of ants to the chemicals. Both assays permitted construction of dosage-response curves and determination of a BI50, the concentration that provided 50% behavioral inhibition.