Field evaluation of attraction and susceptibility of treated monitoring stakes to Australian subterranean termites (Isoptera: Rhinotermitidae)

Two aspects of treated termite monitoring stakes were evaluated in field experiments near Townsville, northern Queensland and at Beerburrum, southeastern Queensland, Australia. First, we examined the attraction of treatedmonitoring stakes to termites, compared with that of untreated stakes, by measuring the rate at which the termites located these stakes. Second, we quantified differences in susceptibility of the 2 types of stakes by recording their mass losses due to termite feeding. The treated stakes had been impregnated with a carbohydrate and protein mixture or with a nominal retention concentration of 2.5% mass/mass (m/m) urea or 5.0 % m/m urea in oven-dry (OD) timber. In Experiment 1 at Townsville, and in Experiment 2 at Beerburrum, there was no significant difference between 20 treated stakes and 20 untreated stakes, with respect to the rate of location and feeding by Coptotermes acinaciformis (Froggatt) (Experiment 1) and Schedorhinotermes seclusus (Hill) and Heterotermes paradoxus (Froggatt) (Experiment 2). In Experiment 3 at Beerburrum, C. acinaciformis, S. seclusus and H. paradoxus were recorded. While there were no significant differences in the rate of location and feeding, with respect to treatments, differences in feeding, with respect to C. acinaciformis and S. seclusus were significant. C. acinaciformis displayed greater feeding-site tenacity than S. seclusus. The terminology commonly employed when referring to the management of termite populations using baits is discussed briefly. We suggest that the term 'bait susceptibility' is preferable to 'bait palatability'. Further, our results suggest that laboratory studies are not a definitive measure of the attractiveness of a compound to termites. Increased consumption of baits, due to the addition of a phagostimulant, needs to be demonstrated in the field before claims can be made of an increase in the efficacy of baits in a termite management program.