The small hive beetle (Aethina tumida) was first found in Florida in 1998. Since then it has invaded Canada, Australia and most recently has been found in Cuba and Italy, and Brazil. Arrival of this insect reveals the inherent risk of moving biological material, often encouraged by international trade agreements and complicated by the nemesis effect.
Besides information published at the original epicenter of the infestation, Florida, there are a number of other sites available on the World Wide Web about this pest. Recommendations about controlling small hive beetle have not changed much since it was first introduced and described in Florida. For more history on this insect, see South African literature by A.E. Lundi.
1. Beekeepers should constantly monitor their operations for presence of the beetle. Detection is relatively easy. The larvae can be examined for the six rather large legs on their front end; wax moth larvae have uniform sized prolegs. In contrast to those of the beetle, wax moth larvae do not usually move toward light, leave a colony nor burrow into the soil. Adult beetles are easy to spot, uniform in color and about one-third the size of an adult worker bee. They rapidly run across the combs and can often be found hiding in places that are not accessible to larger-bodied honey bees. Until more is known about the beetle in a particular area, it should be assumed that it is far more aggressive a scavenger than the wax moth and may overwhelm even strong, healthy colonies.
2. If A. tumida is suspected or detected, the following precautions are suggested:
A. Be scrupulously clean around the honey house. Leave filled supers standing only a short time before extraction. Beetles may rapidly build up in stored honey, especially where honey has been stored over pollen.
B. Be careful stacking infested equipment or extracted supers onto strong colonies. Beekeepers doing this before the beetle was identified may have inadvertently dealt a deathblow to unifested, healthy colonies by providing space for the beetles to build up that the bees could not protect.
C. Pay close attention when supering colonies, making splits or exchanging combs; all these activities could provide room for the beetle to become established away from the cluster of protective bees.
D. Monitor colonies for hygienic behavior; are the bees actively attempting to rid themselves of both larval and adult A. tumida? If not, replace them.
E. Experiment with traps in an attempt to keep larvae from reaching the soil where they complete their development. Try moving bees from place to place. Adult beetles can fly, but their range is not known with certainty. Some areas may be much more hospitable to beetles due to local soil conditions than others. Recent information suggests hives in full sun better withstand beetle infestations.
F. Forget chemical control until research promises some answers. No materials are currently registered and therefore not legal. Most compounds that kill beetles will also kill honey honey bees.
Small hive beetle would seem a good pest candidate for integrated pest control measures. A classic example would be the following advice from Florida Bee Inspector Emeritus Laurence Cutts:
1. Control of Varroa will keep beetle populations from exploding, as there are more bees to deal with the problem in the colony.
2. Keep a fluorescent light on all the time shining on the honey house floor. This attracts beetle larvae, which can then be scooped up in a shovel and put in water where they quickly drown.
3. Remove bottom boards from stacks of stored supers so larvae can drop out of the stacks and be attracted to the fluorescent light.
Mr. David Westervelt of the Florida Department of Agriculture and Consumer Services discussed his most recent experiences with small hive beetle during the January meeting of the American Beekeeping Federation in Fort Worth, Texas. Most losses have been around honey houses, according to Mr. Westervelt, and are involved with improperly storing filled and recently extracted supers. Any wax debris is a prime target for infestation and so cleanliness is essential when beetles are present .
When beetles build up near the honey house, they can then be transported by beekeepers to the out yards, Mr. Westervelt said, spreading the insect around. A key element, again, is to control the beetle near the honey house. Adult beetles can be attracted to brood in strategically placed nucleus boxes, and larvae will congregate around fluorescent light shown on honey house floors, where they can be swept up and put in pans of water.
A small number of beetles can produce a big problem because they tend to lay all their eggs at once, Mr. Westervelt said. A correlation is that you can achieve a good measure of control by systematically eliminating as many adults as possible. During the latest meeting of the Honey Bee Technical Council in Gainesville, FL a young hobby beekeeper, Christopher Creel, described an inside-the-colony technique that he found trapped many adults. He cut a hole in the bottom board and attached a jar that was one-third filled with honey. Over the opening, he bolted a square of Plexiglas elevated by a couple of washers. There was just enough room to allow adult beetles, but not bees, to crawl under the Plexiglas. Many of the beetles eventually wind up in the jar. This trapping idea is passive in nature and requires no chemical use. It could be modified in a number of ways by beekeepers and integrated into colony management on a permanent basis. Trapping has become perhaps the most used method to remove adult beetles from a hive and many designs are currently being marketed.
James Baxter of the Weslaco Bee Laboratory described the situation he saw recently in the beetle’s homeland, the Republic of South Africa. Two phenomena he observed were the amount of propolis bees put at entrances and how clean the insects kept the hive’s bottom boards. Thus, entrances were protected from beetle entry and there were fewer places to hide on the bottom board. Mr. Westervelt said that the propolis and wax bumps often seen on bottom boards are great places for adult beetles to hide. The Cape honey bee (Apis mellifera capensis) also aggressively attacks beetles, according to Mr. Baxter, carrying both adults and larvae from the hive, consuming any exposed eggs, and corralling adults into areas where they do not lay eggs. This behavior appears to be a major reason there are so few problems in out yards. South African beekeepers also use cold rooms for storing filled and extracted supers in almost every case due to potential beetle infestation.
See a presentation by Dr. Jamie Ellis, University of Florida for a fuller description of small hive beetle.