JUVENILE-HORMONE IN ADULT EUSOCIAL HYMENOPTERA - GONADOTROPIN AND BEHAVIORAL PACEMAKER

Studies on the role of juvenile hormone UH) in adult social Hymenopter a have focused on the regulation of two fundamental aspects of colony organization: reproductive division of labor between queens and worker s and age-related division of labor among workers. IH acts as a gonado tropin in the primitively eusocial wasp and bumble bee species studied , and may also play this role in the advanced eusocial fire ants. Howe ver, there is no evidence that JH acts as a traditional gonadotropin i n the advanced eusocial honey bee or in the few other ant species that have recently begun to be studied. The role of JH in age-related divi sion of labor has been most thoroughly examined in honey bees. Results of these studies demonstrate that IH acts as a ''behavioral pacemaker ,'' influencing how fast a worker grows up and makes the transition fr om nest activities to foraging. Hypotheses concerning the evolutionary relationship between the two functions of IH in adult eusocial Hymeno ptera are discussed. (C) 1997 Wiley-Liss, Inc.