Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 28, 2010
Publication Date: May 1, 2010
Citation: Torto, B., Fombong, A.T., Mutyambai, D.M., Muli, E., Arbogast, R.T., Teal, P.E. 2010. Aethina tumida (Coleoptera: Nitidulidae) and Oplostomus haroldi (Coleoptera: Scarabaeidae): Occurrence in Kenya, Distribution within Honey Bee Colonies, and Response to Host Odors. Annals of the Entomological Society of America. 103(3):389-396. 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 bee 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. Several larger beetle species are also known to invade honeybee hives in Africa and to damage honey combs, although they do not reproduce in the hives. These beetles, often referred to as large hive beetles, could become invasive pests if they were accidentally introduced into the US, so their habits and distribution are of interest to scientists in this country. ARS scientists at the Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, are collaborating with scientists at the International Center for Insect Physiology and Ecology (icipe), Nairobi, Kenya, in studying the distribution and habits of large hive beetles, as well as the small hive beetle, in Africa. A species of large beetle not previously known to invade bee hives was found on honeycombs in beehives at four major beekeeping locations in Kenya. Small hive beetles were also found, but these were mostly on the bottom boards of the hives, not on the combs. This information is of interest to scientists responsible for preventing introduction and spread of invasive species into the US, and to the beekeeping industry.
Technical Abstract: Aethina tumida Murray is considered a minor parasitic pest of African honey bee colonies, but little information is available on other coleopteran pests. We surveyed for A. tumida and other beetles in honey bee colonies at four major beekeeping locations: Watamu, Chawia-Taita, Matuu, and Nairobi in Kenya and compared their distribution within the colonies. The presence of A. tumida was confirmed in all the colonies surveyed, while Oplostomus haroldi Witte was found for the first time to be associated with honeybee colonies in varying numbers at all sites, except that none were found in colonies in Nairobi. Over 90% of A. tumida and O. haroldi were found in Watamu and Chawai, located within the coastal province of Kenya. While A. tumida was found mostly on the bottom board of the hives, consistent with previous reports, O. haroldi was found on the frames. Laboratory bioassays using a two choice olfactometer showed that both species were significantly attracted to worker honey bee volatiles and commercial pollen dough inoculated with the yeast Kodamaea ohmeri associated with A. tumida. Based on these findings, we report for the first time O. haroldi as a pest of honeybee colonies in Kenya. We propose that differences in their numbers recorded in the colonies may be due to dissimilarities in the colony environments in the areas surveyed and that odor-baited traps that have been used successfully to manage populations of A. tumida will also be suitable against O. haroldi.