Spread of slow acting bait toxicants and its effect on molting termites across linear foraging distance for Coptotermes formosanus (Isoptera: Rhinotermitidae)

Chitin synthesis inhibitor (CSI)-based baiting programs have been successful in eliminating subterranean termite field colonies. In Coptotermes formosanus, it takes around 3 months to eliminate a colony with noviflumuron (CSI) bait. Although the slow acting CSIs allow the horizontal transfer of the toxicant before the onset of avoidance behavior, there is an incentive to reduce the duration of the treatment for economic purpose.  The time needed for colony elimination depends on 1) the spread of the toxicant in a colony of millions of individuals, 2) the time required for the expression of a toxicant, and 3) the molting event in individual workers. This study provides information on diffusion of a slow acting toxicant- noviflumuron (CSI) over a linear foraging distance of more than 30 m and its effect on workers’ survival. Diffusion of CSI and the observed mortality will be compared with spread of a slow acting toxicant, sulfuramid.