Two factors that influence age at onset of foraging in honey bees are juvenile hormone (JH) and colony age demography (older bees inhibit rate of behavioral development of younger bees). We tested the hypothesis that genetic variation among bees for these factors influences genetic variation in behavioral development. Pairs of colonies showing genetic differences in rates of behavioral development were identified and then bees from these colonies were used for physiological and behavioral assays. Six pairs were assayed, three with European bees only and three with both European and Africanized bees. Genetic variation existed for the following four components: 1) production of JH in 4 out of 6 pairs; 2) sensitivity to JH in 3 out of 6 pairs; 3) sensitivity to social inhibition in 3 out of 6 pairs; and 4) potency of social inhibition in 4 of 6 pairs. Cross-fostering experiments, which allowed all four components to be evaluated simultaneously, revealed genetic variation for production of JH, sensitivity to JH or sensitivity to social inhibition in 5 of 6 pairs; and potency of social inhibition in 5 of 6 pairs. Often there was evidence for genotypic differences in more than one component, and no consistent pattern of association among any of the components. Africanized bees had faster rates of behavioral development than did European bees, but there were no racial differences in patterns of variation among the four components. These results indicate that there are at least several, apparently distinct, physiological processes associated with JH and colony age demography that can be acted upon by natural selection to alter the rate of behavioral development in honey bees.Representative Publications
Giray T, Guzman-Novoa E, Aron C, Zelinksy B, Fahrbach SE, Robinson GE (2000) Genetic variation in temporal polyethism and colony defensiveness in the honey bee, Apis mellifera. Behav. Ecol. 11:44-55. (pdf)
Giray T, Huang Z-Y, Guzman-Novoa E, Robinson GE (1999) Physiological correlates of genetic variation for rate of behavioral development in the honeybee, Apis mellifera. Behav. Ecol. Sociobiol. 47:17-28. (pdf)
Giray T, Robinson GE (1994) Effects of intracolony variability in behavioral development on plasticity of division of labor in honey bee colonies. Behav. Ecol.