The small hive beetle can be a destructive pest of honey bee colonies, causing damage to comb, stored honey and pollen. If a beetle infestation is sufficiently heavy, they may cause bees to abandon their hive. Its presence can also be a marker in the diagnosis of Colony Collapse Disorder for honey-bees. The beetles can also be a pest of stored combs, and honey (in the comb) awaiting extraction. Beetle larvae may tunnel through combs of honey, feeding and defecating, causing discoloration and fermentation of the honey.
It is unknown how this pest found its way into the U.S., but was first discovered to be damaging honey bee colonies in Florida in the late 1990s. It has since spread to more than 30 states, being particularly prevalent in the southeast. The beetles have likely been transported with package bees and by migratory beekeepers, but the adult beetles are strong fliers and are capable of traveling several miles at a time on their own.
In the United States these beetles are usually considered to be a secondary or opportunistic pest, only causing excessive damage after bee colonies have already become stressed or weakened by other factors. Infestations of beetles can put significant stress on bee colonies, which can be compounded by the stress of varroa mites and other conditions. If large populations of beetles are allowed to build up, even strong colonies can be overwhelmed in a short time.
Honey bee colonies appear able to contend with fairly large populations of adult beetles with little effect. However, high beetle populations are able to lay enormous numbers of eggs. These eggs develop quickly and result in rapid destruction of unprotected combs in a short time. There is no established threshold number for small hive beetles, as their ability to devastate a bee colony is related to many factors of colony strength and overall health. By maintaining strong bee colonies, and keeping adult beetle populations low, beekeepers can suppress the beetles’ reproductive potential.
Prevention is the most effective tactic of small hive beetle control. Chemical controls are available, but are of limited use. Good beekeeping management practices in the bee yard and in the honey house are sufficient to contain hive beetle problems in most cases. A combination of cultural and mechanical controls will usually help to maintain beetle infestations within a manageable range.
Keep bee colonies healthy and strong. Reduce stresses from diseases, mite parasitism, and other factors. Maintain and propagate bee stocks with hygienic traits that are better able to detect and remove pests and diseased brood. Eliminate, requeen, or strengthen weak colonies.
Use caution when combining colonies or exchanging combs and hive bodies, because beetles and their eggs can be introduced into other colonies, which can be overwhelmed. Making splits from heavily infested hives can cause a serious outbreak if insufficient numbers of bees remain to protect the hive. Avoid over-supering hives, which increases the area that the bees must patrol.
Maintain a clean apiary and honey house to reduce attraction to beetles. Avoid tossing burr comb onto the ground around hives, which may attract pests. Adult beetles tend to prefer shady locations. If possible, place hives where they receive direct sunlight at least part of the day. Keep hives and frames in good condition. Warped, cracked and rotten hive bodies provide beetles with many places to hide, and make them more difficult to detect by bees or beekeepers. When debris is left to accumulate on a bottom board, beetle larvae can complete pupation inside the hive. Regular cleaning or use of screen bottom boards can prevent this build-up of debris.
Honey that is removed from a colony should be extracted within 1-2 days. Wax cappings are an attractive food for beetles, and should be processed quickly or stored in sealed containers. Honey supers can be removed from weak colonies to lessen the territory of combs that the bees must patrol. If not ready for extraction, these supers can be placed on strong colonies, in a manner similar to protecting them from wax moth infestations. However, if small hive beetles or their eggs are present on the combs, the addition of these beetles can be sufficient to cause the strong colony to collapse. Honey supers can be frozen at -12°C (10°F) for 24 hours to kill all stages of beetles before transferring supers to a strong colony. Store empty supers under conditions of good air circulation and less than 50% humidity.
Pollen traps should not be left on heavily infested hives for extended periods. The unprotected pollen can serve as a substantial protein source for beetles, as well as a protected breeding site.
Utilize mechanical traps in the hive to reduce the number of adult beetles that can produce eggs, while also reducing the need for pesticides.
The pupal stage is a vulnerable time in the beetle life cycle. Slightly moist, loose, sandy soil is optimal for their development. Locating colonies on hard clay or rocky soil, rather than light sandy soil, can reduce the number of beetle larvae that successfully pupate.