Within- and between-individual (co)variance partitioning reveals limited pleiotropic effects of testosterone on immune function,sexual signaling,and parental investment

Behavioral Ecology and Sociobiology - An individual’s home range, or how much space it requires to obtain resources and meet its needs for survival and reproduction, affects the scale of many...     

Age-dependent attractivity of males�� sexual pheromones in Bombus terrestris (L.) [Hymenoptera, Apidae]

Males of Bombus terrestris (L.) adopt a patrolling behaviour during their nuptial parade using cephalic labial gland (CLG) secretions containing sexual pheromones to attract conspecific virgin queens. The changes in chemical composition of their CLG secretions with age are quite well known. In this study, we investigate the evolution of CLG secretions with age in greater detail and compare behavioural reactions of conspecific virgin queens to the secretions. We show that compounds of CLG secretions follow two profiles. Most of the compounds increase from the first day after emergence until the bees are 15-days-old and then decrease. Others are less abundant in 1 to 15-day-old males and then increase (e.g. tricosane, tricosene, henicosane, tetradecanoic acid, pentacosene, pentacosane, heptacosene, heptacosane, nonacosene and geranylcitronellyl tetradecanoate). Differences in secretion composition lead to preferences of virgin queens for males according to the male??s age. Virgin queens prefer the pheromonal gland secretions of bees of the following ages in decreasing order; 1?day?=?3?days?<?7?days?=?30?days?<?15?days?<?10?days. The virgin queens are strongly attracted by secretions containing high amounts of 2,3-dihydrofarnesol, 2,3-dihydrofarnesal, ethyl dodecanoate and hexadecanol. On the contrary, geranylcitronellol is more abundant in 30-day-old males.