Journal of Chemical Ecology, Vol. 27, No. 5, 2001 TASK-RELATED CHEMICAL ANALYSIS OF LABIAL GLAND VOLATILE SECRETION IN WORKER HONEYBEES (Apis mellifera ligustica) TAMAR KATZAV-GOZANSKY, 1,* VICTORIA SOROKER, 1,3 ARMIN IONESCU, 1 GENE E. ROBINSON, 2 and ABRAHAM HEFETZ 1 1 Department of Zoology, George S.Wise Faculty of Life Sciences Tel Aviv University Ramat Aviv, Tel Aviv, Israel 2 Department of Entomology University of Illinois Urbana, Illinois (Received October 4, 1999; accepted January 10, 2001) Abstract—Chemical analyses revealed that the labial gland complex of worker honeybees possesses a series of hydrocarbons dominated by odd-numbered carbon chain alkanes along with minor amounts of alkenes and branched alkanes. Foragers contained significantly more secretion than nurse bees. Experiments with bees from colonies induced to have a division of labor independent of age revealed that the differences in the amount of secretion were task, but not age dependent. Key Words—Honeybees, labial glands, exocrine glands, secretion, hydrocar- bons, forager bees, task specificity. INTRODUCTION The labial (salivary) gland complex comprises two pairs of glands, one in the head and one in the thorax, both of which connect through a common duct to the mouth (Cruze Landim, 1967). They are intermittently developed in bees, and little is known about the chemistry or function of their secretion. In the mason bee, Chalicodoma siculum, the head gland secretion is composed of hydrocarbons that are used to waterproof brood cells (Kronenberg and Hefetz, 1984). Male carpenter * To whom correspondence should be addressed. e-mail: katzavt@post.tau.ac.il 3 Present address: Department of Entomology, Institute of Plant Protection, Agricultural Research Organization, Volcani Center, Beit Dagan, 50250 Israel. 919 0098-0331/01/0500-0919$19.50/1 C  2001 Plenum Publishing Corporation