EFFECTS OF POPULATION-DENSITY ON TUNNELING BY FORMOSAN SUBTERRANEAN TERMITE (ISOPTERA, RHINOTERMITIDAE) THROUGH TREATED SOIL

Tunneling behavior of Coptotermes formosanus through soil treated with chlordane, chlopyrifos or permethrin was significantly affected by population density. When exposed to each of these termiticides at population densities of 0.03 or 0.003 g of termites per milliliter container volume, termites constructed a greater number of tunnels of greater length at the high population barrier. At a high population density, C. formosanus may be able to bridge a termiticidal barrier. At low population density, termites constructed significantly fewer tunnels in soil treated with permethrin; tunnel height and cumulative tunneling distance were slight, but comparable for chlorpyrifos and permethrin. Cumulative tunneling distance and maximum tunnel height were significantly greater for chlordane than the other chemicals at low and high population densities. -from Author