Small Hive Beetle Larvae
The small hive beetle (SHB), Aethina tumida Murray (Coleoptera: Nitidulidae), was identified from honey bee colonies (Apis mellifera) in Florida by M.C. Thomas of the Florida Department of Agriculture, June 1998. This was the first report of this insect in the Western Hemisphere; it was previously known only in sub-Saharan Africa. Adult beetles are 5mm long, dark brown to black and can be found within honey bee colonies. Eggs are laid in concealed areas and empty cells and larvae seek out pollen bee brood and honey to feed upon. The feeding of larvae causes honey to drip from the cells and often ferment, leaving a repellent on combs that can cause adult bees to abandon the comb and leave the hive. Beetle larvae complete their feeding on bee combs and then migrate outside to pupate in the soil. Development from egg to adult beetle takes 30-80 days. Reports from South Africa suggest that the beetle is rarely a significant pest with African bees. However, since beekeepers in the United States manage a different race of honey bee than in South Africa, the effects of this pest on U.S. beekeeping are largely unknown.
Distribution in the United States
The small hive beetle has been found in 30 states, most of which are East of the Mississippi River, as of October 2001. Migratory beekeepers transport bee colonies from areas known to be infested with the small hive beetle and the probability that this pest is more widespread is very real due to the migratory pollination demands within the U. S.
Nature of the problem
The small hive beetle is considered a secondary pest in South Africa, attacking small or weak hives but rarely affecting strong hives. The honey bees in South Africa are primarily Apis mellifera scutelata, an aggressive bee that has excellent housecleaning and defensive traits. In contrast, the bees kept in North America are predominately A. m. ligustica or A. m. carnica and differ in behavior from African bees. The difference between races of bees coupled with different climatic and colony management styles between South Africa and the United States make it difficult to predict the impact of this new pest on the U. S. beekeeping industry. Reports from states with SHB have indicated occasional problems with beetles infesting and destroying hives in the apiary. However, more problems have been reported from damage by SHB to stored honey.
Damage to colonies and stored honey
Small hive beetle larvae affect combs of stored honey and pollen and will also infest brood combs. During the feeding action by larvae an associated repellent sticky substance is laid down on the combs and this can result in bees abandoning the hive. When honeycombs are removed from colonies, bees then no longer protect the combs allowing larvae to feed uninhibited. The management practice of removing honey and then storing it in warehouses prior to extraction will need to be changed with the introduction of this beetle. Additionally, the handling of wax cappings and honey in areas known to have the small hive beetle will require increased sanitation. Our research has shown that reducing relative humidity below 50% where honey is stored will inhibit SHB eggs from hatching and thus reduce or eliminate larval damage in honey.