On the origin and properties of scent marks deposited at the food source by a stingless bee, Melipona seminigra

Abstract

Some species of stingless bees of the genus Melipona were reported to scent mark food sources but little is known about the chemical signals involved. We studied the origin and some properties of such scent marks in M. seminigra. Results from choice experiments suggested that the bees do not scent mark the food (sugar water) itself and that abdominal droplets were excluded as the signal source. Extracts of the most distal tarsomeres, however, attracted recruits in the same way as natural scent marks. We conclude that M. seminigra scent marks a food source by leaving "footprints" secreted at the leg tips. The footprints of at least 40 visits were needed to effectively scent mark. The chemical signal has an active range of about 1 m and its effect persists for about 2 hours. In the absence of footprints no scent marking effect was seen. This finding excludes the importance of mandibular gland secretions (if at all present) for the scent marking observed.