Acknowledgment: Extract taken from an article written by BC Peters and CJ Fitzgerald, Queensland Forestry Research Institute, P.O. Box 631, Indooroopilly, Qld 4068 and published in the April 1998 edition of PESTALK
“For the past 30 years, or so, subterranean termite management in Australia has relied mainly on chemically-treated soil barriers using the highly persistent cyclodiene (oganochlorine) insecticides (aldrin, dieldrin, chlordane and heptachlor). These chemicals were de-registered and withdrawn from use on the 30th of June 1995.
Alternative strategies for subterranean termite management in buildings and structures have been developing, well before this withdrawal. One of those strategies, which uses so-called “termite baiting systems”, is introduced in this publication. The concept of termite baiting, the aggregation of termites in the baiting station and the application of toxicants are discussed.”
Concept of termite baiting
“A bait is a food, or some substance. used to attract, entice or lure a specific organism to a desired location. Therefore, baiting for subterranean termites is not strictly “baiting” because the termites are not strictly “attracted, enticed or lured” to most baits. The deficiency may be with the baits used and not with the term. However the principal of the baiting techniques is to have a susceptible substance in an aggregation device (“bait station”) on which the termites aggregate and continue to feed once they have found the bait station. Bait stations can be placed in below-ground or above-ground situations. Placements of the baits in areas conducive to termite activity (“directed placement”) enhances the chance of making contact with the foraging termites.
Some bait toxicants eliminate the colony while others suppress the colony. however, both methods reduce potential to cause further damage to timbers.
Termite baiting is most beneficial when used as part of an integrated-pest-management strategy. Colony elimination or suppression should be followed by hazard reduction and regular inspections. Monitoring should continue because only a small amount of toxin is used and does not prevent foraging by other termites that may be present in the foraging range of a timber structure.”
“There are few critical dimensions or material. Typically, boxes are about 500x300x200mm high and are constructed of polystyrene (broccoli box) or untreated timber box, buried in soil to about 100mm. The lid should be seal tightly, to prevent the entry of ants and drying of the contents inside the box. Holes in the bottom of the box permit the entry of termites. A small window covered by clear plastic in the top or end of the box facilitates inspection. A sheet of white paper (blotting or tissue) against the inside of the window may be used to detect termites (once termites have eaten or stained the paper) without disturbing them. Wetted-corrugated cardboard and thin strips of susceptible wood are alternated in layers as the bait substrate. These are easily removed to obtain the termites.”
Placement of baits
“In Australia the main problem with baiting techniques has been the inconsistency of termites locating and accepting the baits.
Direct placement of in ground stations should be in dark, moist quite places, rather than at regular intervals around a structure. Primary areas for directed placement include: areas around drains, areas adjacent to “wet areas” (bathroom, kitchen and laundry) where plumbing may enter the structure, garden beds adjacent to the structure and around standing trees or stumps.
With above-ground stations, baits placed in contact with infested timbers are often by-passed and not eaten. Stations placed at feeding sites, rather than on termite “highways” appear more successful. Electronic devices to detect feeding sites are under development.
Competing food sources for termites usually cannot be removed and thus food choices are always available to the termites being baited. In some cases, baits have been pre-decayed with a suitable fungus to enhance bait acceptance. The fungus used varies with the termite species. Similarly, nitrogen additives, principally urea and selected amino acids , have been used to increase the feeding on baits by Coptotermes spp.”
“Termite baiting is still a combination of art and science. Termite baiting systems are largely in a developmental or refinement phase in Australia. They are most beneficial when used as part of an integrated-pest-management strategy and are not the complete answer to termite management. Colony elimination or suppression should be followed by hazard reduction and regular inspection. A better understanding of termite foraging habits and behaviour will enhance bait-station design and placement for termite aggregation and bait-toxicant application.”