HARRISON, J.F.*; FEWELL, J.H.; GRAYSON, D.L.; HUNT, G.J.; BARND, B.D.; Arizona State University; Arizona State University; Arizona State University; Purdue University; Purdue University: An Environmental Physiologist Perspective on the Invasion of the Americas by Africanized Honey Bees

Africanized honey bees are a classic invasion species: introduced by man, spreading rapidly, and out-reproducing native species including the conspecific European honey bee. This invasion has had major human health and economic effects, some of which may further increase. Physiological and ecological approaches were used to successfully predict the distribution limits of Africanized bees. Behavioral differences (honey storage) rather than thermal tolerances or heat production appear to explain range differences between bee races. Multiple traits appear to account for the success of Africanized vs. European honey bees, including: 1) faster colony growth rate, 2) reproduction at smaller colony size, and 3) greater dispersal tendency and ability. Several studies suggest that faster colony growth rates relate to a greater tendency to forage for pollen vs. nectar, which allows a higher intake of protein for brood production. Africanized worker honey bees have greater mass-specific flight metabolic rates but do not appear to use these capacities to bring in more resources. However, the higher flight metabolic capacities of reproductives may facilitate the greater dispersal capacities of Africanized swarms and possible reproductive advantages of Africanized males. Quantitative trait loci mapping has identified specific loci correlated with both behavioral and physiological trait differences between Africanized and European bees, and provides beginning steps toward determination of the specific genes responsible for the invasive success of these bees. Supported by NSF IBN 093410 to JHF, JFH and GJH.