Trail communication during foraging and recruitment in the subterranean termite Reticulitermes santonensis De Feytaud (Isoptera, Rhinotermitidae)

The search for food in the French subterranean termite Reticulitermes santo nensis De Feytaud is organized in part by chemical trails laid with the sec retion of their abdominal sternal gland. Trail-laying and -following behavi or of R. santonensis was investigated in bioassays. During foraging for foo d termites walk slowly ton average, 2.3 mm/s) and lay a dotted trail by dab bing the abdomen at intervals on the ground. When food is discovered they r eturn at a quick pace ton average, 8.9 mm/s) to the nest, laying a trail fo r recruiting nestmates to the food source. While laying this recruitment tr ail the workers drag the abdomen continuously on the ground. The recruitmen t trail is highly attractive: it is followed within a few seconds, by more nestmates, and at a quicker pace ton average, 6.4 mm/s) than foraging trail s ton average, 2.9 mm/s). The difference between foraging and recruitment t rails in R. santonensis could be attributed to different quantities of trai l pheromone. A caste-specific difference in trail pheromone thresholds, wit h workers of R. santonensis being more sensitive to trails than soldiers, w as also documented: soldiers respond only to trails with a high concentrati on of trail pheromone.