The trail pheromone of the termite, Trinervitermes trinervoides

By using a T-junction choice assay workers of Trinervitermes trinervoides have been shown to lay and follow pheromone trails. The trials are not polarized and there is a quantitative relation between the number of termites laying the trail and the fraction of test termites which follw correctly. Workers reinforce trails whenever they follow them, and the degree of this reinforcement seems to be independent of trail strength. The trail pheromone is volatile and need not be perceived by contact chemoreception. Activity loss from filter paper is approximately exponential with a half-life of about 2 hr. Extracts of papers over which workers had laid trails were used to show a linear relationship, on a log-probit scale, between dose and response. Soldier termites also follow trails about as well as do workers, but workers lay trails that are about six to seven times as strong as soldier trails. No preference of either caste for their own trails could be demonstrated. Thin-layer chromatography indicated that the trail pheromone(s) is a fairly polar substance.