Three concentrations of the bistrißuron were used:0(untreatedcontrol),0.5,and1.0% over an 8 wk period.Both doses of bistrißuron bait eliminated (viz. termites absent from nest or mound) termite colonies:83% of colonies (10 of 12) were either eliminated or moribund (viz. colony had no reproductivecapacity and decreased workforce) after 8 wk, compared with none of the control colonies.
There maining two treated colonies were deemed to be in decline.Early signs that bistrißuron was affecting the colonies included: 3 wk after baiting mound temperatures showed a loss of metabolic heat, 4 wk after baiting foraging activity in feeding stations was reduced or absent,and dissection of two mounds at 4 wk showed they were moribund.Colony elimination was achieved in around half or less the time,and with less bait toxicant,than other bait products tested under similar conditions in the field,because of either the active ingredient, the high surface area of the pellets, or a combination of both. This suggests the sometimes long times reported for control using baits may be reduced signiÞcantly. The use of a mound building species demonstrated clearly colony level effects before and after termites stopped foraging in bait stations