Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2009
Publication Date: 6/1/2009
Citation: Arbogast, R.T., Baldwyn, T., Willms, S.D., Teal, P.E. 2009. Trophic habits of Aethina tumida (Coleoptera:Nitidulidae): Their adaptive significance and relevance to dispersal. Environmental Entomology. 38(3):561-568.
Interpretive Summary: The small hive beetle is a native of Africa where it is considered a minor pest of honey bees, and until recently it was thought to be limited to that continent. However, it was detected in Florida in 1998 and by 2004, it had spread to 30 states. It now poses a major threat to the beekeeping industry of the United States. The beetle enters hives where it lays eggs and multiplies rapidly, feeding on pollen, honey, and bee brood. It contaminates honey, causing it to ferment and eventually destroys the hive. ARS scientists at the Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, Florida have found that the beetle occurs in woodlands near which there are no managed honey bee colonies, suggesting the possibility that the beetle is able to breed in the absence of bees by utilizing diets other than pollen, honey, and bee brood. Experiments conducted at the Center demonstrated that the beetle is capable of multiplying on diets of various fruit. These findings could have serious implications, because the ability of the small hive beetle to reproduce in the absence of bees may thwart efforts to control populations in honey bee hives and because it facilitates expansion of the beetle’s range. This information will be of use to scientists in developing control methods that will benefit beekeepers directly.
Technical Abstract: Aethina tumida Murray is an African native that has become an important pest of honey bee colonies in North America and Australia. Adults and larvae feed on pollen, honey, and brood in bee hives. The beetle is also able to feed and reproduce on fresh or rotting fruit, but is not known to occur naturally on this diet. We compared the fitness – as measured by progeny production, weight of progeny, development rate, and survival of immature stages – of beetles reared on various diets of fruit and bee products. Fitness levels on all of the diets were sufficient for population growth of the beetle. Using baited flight traps to monitor the presence of A. tumida, we found persistent though tenuous populations in wooded habitats lacking managed bee colonies. On the basis of these findings and the habits of other nitidulid beetles, we propose that A. tumida is an ecological generalist able to maintain adequate levels of fitness in marginal environments but able to reach high levels of fitness in favorable, resource rich environments, such as honey bee colonies. Although our findings support this hypothesis, definitive proof would require rearing beetles from potential hosts collected in various habitats, trapping adults as they emerge from soil, or other methods that would confirm feeding or reproduction at a particular site. The hypothesis has significance for active dispersal and range expansion, because reproduction in the absence of bees would facilitate long range dispersal by flight through successive generations.