FORMULATING FARNESOL AND OTHER ANT-REPELLENT SEMIOCHEMICALS FOR EXCLUSION OF ARGENTINE ANTS (HYMENOPTERA, FORMICIDAE) FROM CITRUS TREES

Lemon trees banded with experimental formulations of farnesol and othe r natural ant repellents were examined for efficacy of disruption of t he foraging of the Argentine ant, Linepithema humile (Mayr), at varyin g periods of time after application. Excellent disruption of foraging was achieved by the use of a band constructed from a single strand of cotton twine permeated with 40 mg each of farnesol and Stickem per cen timeter of twine. An ''ant tape,'' consisting of twine similarly perme ated with farnesol and Stickem and covered with a strip of waxed paper , was under some conditions superior in duration of disruption of ant foraging to the noncovered, treated twine. Efforts to produce an effec tive barrier from farnesol mixed with Stickem and beeswax and formulat ed into a paste, which was then applied around tree trunks, have not b een successful. The better formulations of famesol tested have given b etween 2 and 3 mo of complete ant exclusion from banded trees. Other t ested repellent compounds have not been as active or provided as long a duration of effectiveness as farnesol.