Percent lipid is associated with body size but not task in the bumble bee Bombus impatiens.

In some group-living organisms, labor is divided among individuals. This allocation to particular tasks is frequently stable and predicted by individual physiology. Social insects are excellent model organisms in which to investigate the interplay between physiology and individual behavior, as division of labor is an important feature within colonies, and individual physiology varies among the highly related individuals of the colony. Previous studies have investigated what factors are important in determining how likely an individual is, compared to nestmates, to perform certain tasks. One such task is foraging. Corpulence (i.e., percent lipid) has been shown to determine foraging propensity in honey bees and ants, with leaner individuals being more likely to be foragers. Is this a general trend across all social insects? Here we report data analyzing the individual physiology, specifically the percent lipid, of worker bumble bees (Bombus impatiens) from whom we also analyze behavioral task data. Bumble bees are also unusual among the social bees in that workers may vary widely in size. Surprisingly we find that, unlike other social insects, percent lipid is not associated with task propensity. Rather, body size closely predicts individual relative lipid stores, with smaller worker bees being allometrically fatter than larger worker bees.

Effects of home access and availability of alcohol on young adolescents' alcohol use.

AIMS: The purpose of the present study was to examine the effects of parental provision of alcohol and home alcohol accessibility on the trajectories of young adolescent alcohol use and intentions. DESIGN: Data were part of a longitudinal study of alcohol use among multi-ethnic urban young adolescents who were assigned randomly to the control group of a prevention trial. SETTING: Data were collected from a cohort of youth, and their parents, who attended public schools in Chicago, Illinois (2002-2005). PARTICIPANTS: The sample comprised the 1388 students, and their parents, who had been assigned randomly to the control group and were present and completed surveys at baseline, in the beginning of 6th grade (age 12). The sample was primarily low-income, and African American and Hispanic. MEASUREMENTS: Students completed self-report questionnaires when in the 6th, 7th and 8th grades (age 12-14 years; response rates 91-96%). Parents of the 6th grade students also completed questionnaires (70% response rate). FINDINGS: Student report, at age 12, of parental provision of alcohol and home alcohol availability, and parental report of providing alcohol to their child and the accessibility of alcohol in the home, were associated with significant increases in the trajectories of young adolescent alcohol use and intentions from ages 12-14 years. Student report of receiving alcohol from their parent or taking it from home during their last drinking occasion were the most robust predictors of increases in alcohol use and intentions over time. CONCLUSIONS: Results indicate that it is risky for parents to allow children to drink during early adolescence. When these findings are considered together with the risks associated with early onset of alcohol use, it is clear that parents can play an important role in prevention.