A REVIEW OF THE EVALUATION CRITERIA FOR BAIT-TOXICANT EFFICACY AGAINST FIELD COLONIES OF SUBTERRANEAN TERMITES (ISOPTERA)

Three variables; 1) foraging activity, 2) foraging territory, and 3) f oraging population size, have been used for evaluation of toxicant-bai t efficacy against field colonies of subterranean termites. Of these 3 variables, foraging activity was used in all studies. Presence or num ber of termites in treated or untreated food, or consumption of treate d or untreated food were used to measure foraging activity. Use of tox icant-bait consumption to measure the effects of bait toxicant on fora ging activity is misleading because it may only represent bait avoidan ce by termites. Measurement of the consumption of untreated baits plac ed in the vicinity of a target colony may be a more accurate reflectio n of the effects of bait-toxicants on overall foraging activity. Ideal ly, foraging territory of the target colony needs to be delineated usi ng dye markers or radioisotopes, so that bait-toxicant placement can b e associated with a given colony. The 3rd variable, foraging populatio n size, may not be necessary when the objective and outcome of baiting is colony elimination. Estimate of population size, however may be an essential variable for demonstration of population suppression.