The effect of bait design on bait consumption in termites (Isoptera: Rhinotermitidae) T.A. Evans * and P.V. Gleeson CSIRO Entomology, Canberra, ACT 2601, Australia Abstract The efficacy of baiting as a pest control method relies on the bait appealing to the pest species. In the case of wood-eating termites, bait stations should be designed to encourage termite presence and to maximize their consumption of bait matrix in order to expedite control in minimal time. A field experiment examined the effect of bait size (one large bait or four small baits of equivalent total size, with commensurate inspection and replacement schedules), compaction (tightly rolled or loosely folded) and composition (paper only or paper plus wood) on termite presence and on untreated bait paper removal rates over four months. All three factors were significant, with bait size the most important factor, followed by compaction and then composition. The least effective baits were small, compacted (rolled) paper-only baits with monthly inspections; these had the highest abandonment rate (70%) and had the least paper removed (mean of 24 g). The most effective baits were large, folded paper-plus-wood baits with inspections at two months; these had the lowest abandonment rate (20%) and had the highest paper removal (mean of 112 g). The more than four-fold difference between these baits types demonstrates that bait efficacy can be altered considerably merely by changing bait design without adding new ingredients to the bait matrix. Keywords: termites, bait size, bait compaction, bait composition, control Introduction Baiting has been promoted as a desirable method of termite pest control. It is lauded as environmentally sound as it uses very small amounts of insect specific toxicants that are administered in localized baits that are targeted at the pest species (i.e. not large amounts of toxicants spread over large areas around a house). However, in order for baiting to work successfully, termites must find and consume the bait matrix and for the toxicant contained therein to be transferred back to the nest. These requirements are not inconsequential: a successful baiting programme can take up to nine months (e.g. 3–9 months Su, 1994; 7 months Tsunoda et al., 1998; 3–7 + months Su & Scheffrahn, 2000), which is much slower control than that provided by other methods. How can control using baiting be accelerated? A good understanding of termite foraging behaviour, and in particular food preferences, may contribute to the design of a bait station ‘optimized’ for termite foraging. ‘Optimized’ in this context means that the preferred termite food is presented in the most appealing fashion so that termites collect the bait matrix and return it to their nest faster, which in turn should increase the speed at which control occurs. It is important to put such activity in the context of total foraging activity of a termite colony as the bait stations will be in competition with other food sources for attention from foragers (Forschler, 1996; Perrott et al., 2004). Work has been conducted on termite food and foraging preferences (e.g. Howard & Haverty, 1979; Rust et al., 1996; Suoja et al., 1999), yet little of this appears to have been included into bait station design. This is because most economically important, wood-eating termite species evolved to eat relatively large pieces of timber (which is the reason why these species are pests), including whole trees (e.g. Coptotermes species; Hill, 1942; Greaves, 1962, 1967; * Fax: +61 2 6246 4000 E-mail: Theo.Evans@csiro.au Bulletin of Entomological Research (2006) 96, 85–90 DOI: 10.1079/BER2005397