Dennis R. Ring, Wilson, Gary K.
In Africa the small hive beetle (SHB) is a secondary pest that scavenges weakened colonies. Here in the United States, the larvae tunnel through combs, killing bee brood and ruining combs. The SHB eats pollen, brood, honey, dead adult bees and combs. The beetles defecate in honey and cause it to ferment, producing a frothy mess that leaks out of the combs. The contaminated honey that smells like rotting oranges cannot be sold and is unpalatable to bees. The bees will abandon combs and colonies as the infestations grow and spread.
Adult beetles are attracted to honeybee colonies to reproduce. It takes a combination of honey, pollen and adult bees to attract them. Research is underway to identify the chemical signals that SHBs use to locate apiaries. Colony odors released during hive inspections serve as a stimulus for beetles to hone in on the apiary. Hives that are shaded, stressed or weakened are the first to be invaded. Weak or queenless hives are more susceptible to SHB damage. Maintaining strong, healthy colonies with young productive queens is one of the management techniques for resisting SHB damage.
Colonies with strong house cleaning and defensive traits are more resistant to small hive beetles. Strong colonies will remove larva, confine beetles in propolis and prevent access to the colony by aggressively harassing adults trying to enter the colony. Small hive beetles protect themselves from bee attacks by retracting their head and legs under their exoskeleton protected body. Bees will chase the beetles until they find a corner or crevice in which to hide.
Most traps are designed to use one or more of the small hive beetles normal actions against them. When they enter the hive by the bottom board, bees chase them around until they find a corner or crevice. Bottom board traps have slots too small for bees to enter, but small enough for SHBs to escape into. The pans or catch basins into which they drop are filled with oil. The non-toxic vegetable oil coats and suffocates the beetles. The original bottom board traps were made from corrugated cardboard or plastic with the outside paper removed to reveal the corrugation. They were placed corrugated side down on the bottom board toward the rear of the hive. The beetles would seek refuge under the cardboard and be killed by the plastic CheckMite + impregnated strip. The active ingredient is coumophos and it is important to follow the label instructions when using this material. There are traps that may be used within the hive. One replaces a portion of comb and fastens to the bottom bar of a frame, it is partially filled with vinegar or vegetable oil and has small slots into which the SHBs may escape the harassing honeybees. There are also smaller traps that rest between the top bars and are partially filled with vegetable oil.
The odors of decaying or fermenting hive products (vinegar, pollen and honey) are extremely attractive to SHB. Some trapping has been done with an external trap using a bait made of pollen dough conditioned by allowing male SHB to feed on it for three days. Small hive beetles bring in yeast that grows on the pollen and as it ferments it releases compounds that mimic honey bee alarm pheromones. This chemical signal is highly attractive to other bees. Experimentation will continue until the perfect aggregating pheromone is isolated and commercialized. Managing for strong, healthy colonies and practicing good sanitation will be our best defense against small hive beetles until then.