CHEMISTRY AND BIOCHEMISTRY OF INSECT BEHAVIOR, PHYSIOLOGY AND ECOLOGY
Location: Chemistry Research Unit
Title: Estimating reproductive success of Aethina tumida (Coleoptera: Nitidulidae) in honey bee colonies by trapping emigrating larvae
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 27, 2011
Publication Date: February 1, 2012
Citation: Arbogast, R.T., Torto, B., Willms, S.D., Fombong, A.T., Duehl, A.J., Teal, P.E. 2012. Estimating reproductive success of Aethina tumida (Coleoptera: Nitidulidae) in honey bee colonies by trapping emigrating larvae. Environmental Entomology. 41(1):152-158.
Interpretive Summary: The small hive beetle was known only as a minor pest of honey bees in sub-Saharan Africa until its detection and spread in the United States (1998) and Australia 2002). The massive expansion of it geographic range and its ability to seriously damage European honey bee colonies in the newly occupied regions have demonstrated its invasive capability and serious pest potential. Adult beetles enter hives, where they lay eggs and feed on pollen, honey, and bee brood. The larvae have the same food habits but inflict more damage. Full grown larvae leave the hive, burrow into the soil and pupate. Adults emerging from the soil may re-enter nearby hives or disperse over the landscape in search of other hosts. Researchers seeking to understand the habits of the beetle to better control it have made great strides, but much remains to be learned about how population levels of the beetle are influenced by conditions in the hive. Progress along these lines has been hampered by lack of a non-intrusive method for sampling beetle populations in hives to estimate their abundance and changes in abundance over time. ARS scientists at the Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, have developed a hive entrance trap that captures most emigrating larvae as they reach the edge of the bottom board. Their numbers reflect the beetle’s reproductive success, and the trap provides an accurate estimate of their numbers. The trap will be useful to researchers for studies of beetle population dynamics in hives. Although we regard the traps primarily as a research tool, they could find limited application as a control method, as for example in hobby bee yards or other small operations.
We describe a trap that fulfills the need for an effective, non-intrusive means of sampling small hive beetle (Aethina tumida Murray) populations in honey bee hives. Counting the numbers of mature larvae leaving hives for pupation in the soil provides an estimate of progeny production within the hive; mature larvae are also the easiest stage to trap and count. Assuming there are no holes in the hive, the larvae must exit through the hive entrance, to which they are strongly attracted by light. An appropriately designed and situated trap should capture virtually all emigrating larvae. Our trap is attached to the bottom board, flush with its outer edge. It consists of two rectangular sections of clear acrylic plastic held together by stainless steel catches. The lower section is a trough containing water and detergent to kill the larvae, and the upper section has a narrow gap that allows larvae to enter and then fall through a screen that excludes bees. Releasing the catches allows trough removal to count or dispose of captured larvae. Experiments showed that the efficiency of the trap is at least 94% and revealed its potential as a research tool for study of beetle population dynamics in bee hives.