New Pest Alert - Small Hive Beetle Found in Tennessee
by John A. Skinner
Extension Apiculturist
University of Tennessee
The small hive beetle, Aethina tumida, has recently been positively identified from honey bee colonies in Polk County, Tennessee. We had anticipated the arrival of the beetle in Tennessee after it's discovery in Florida, Georgia, South and North Carolina, and published an alert in 1999 (The small hive beetle - a new pest of honey bees; University of Tennessee Entomology and Plant Pathology Info 637) that has been widely distributed to warn beekeepers about this pest including how to identify adult and larval beetles and methods to detect the pest. Our inspections in Memphis, Sequatchie Valley, Johnson, Giles and Lincoln Counties sponsored by USDA CAPS Program failed to detect beetles in honey bee colonies. This alert will describe the initial find in detail by a beekeeper who quickly notified Dr. Ray McDonnell, Tennessee State Apiarist. This information was provided by Mr. Walker Gray Haun, Plant Certification Administrator of the Tennessee Department of Agriculture
September 14, 2000: A beekeeper contacted Dr. Ray McDonnell about black beetles and larvae he discovered in a dead honey bee colony. He had melted the remaining wax comb and found adults in the wax as well as adults and larvae in the hive.
September 19, 2000: Dr. McDonnell sent the beetle specimens to Dr. Jeff Pettis at the USDA-ARS Bee Laboratory in Beltsville, MD for identification.
September 22, 2000: Dr. McDonnell inspected 52 colonies in Polk County near the location where the original specimens were found. In an apiary of 48 colonies he found 15 colonies with the suspect beetles. All colonies were placed under a stop movement action until further investigation could be undertaken.
September 25, 2000: Dr. Jeff Pettis from USDA reported to Dr. McDonnell that the beetle specimens were positively identified as the small hive beetle.
September 29, 2000: Dr. McDonnell inspected 73 honey bee colonies in two apiaries and found no small beetles hive beetles.
October 2, 2000: In summary a total of two apiaries owned by two different beekeepers in Polk County, Tennessee were found to contain small hive beetles.
November, 2000: Efforts continue to further determine distribution and plan for treatment to contain and reduce the infestation. The University of Tennessee will be assisting The Tennessee Department of Agriculture in this effort, especially to provide any new information to beekeepers.
Small Hive Beetle - Overview:
We thank Dr. Mike Hood (Clemson University) and Dr. Keith Delaplane (University of Georgia) for providing information included in the material presented below.
It is unknown how the small hive beetle entered the US. Although this beetle is considered a minor hive pest in South Africa where it is a native pest of the African honey bee, it has caused considerable damage to honey bee colonies in southeastern US, especially in Florida where beekeepers were entirely unprepared and knew little about the pest. This beetle could cause serious damage to Tennessee bee colonies. Therefore, we should make sure beekeepers know how to detect the beetles and how to treat to control them. The beetles have spread to 13 states in the US mainly due to movement of beetle infested colonies. We are not aware of the presence of any natural enemies (predators, parasites, pathogens) in the US that could reduce the number of beetles substantially. To date small hive beetles have been identified in Florida, Georgia, Iowa, Maine, Massachusetts, Minnesota, New Jersey, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee and Wisconsin.
Beetle Biology: The adult beetles are 1.4 inch (6mm) long, dark brown to black, flattened , oval to oblong in shape. The adults enter colonies of honey bees and lay eggs which develop into whitish, elongate larvae, tapered at the anterior and posterior ends. The larvae burrow through combs in the colony where they feed on honey and pollen. As they feed they damage combs, uncap honey and the fermenting honey may be observed to run out of the colony entrance. As the number of beetles increase, larval feeding and defecation induces bees to abandon their colony. The larvae leave the colony, burrow into the ground and pupate in the soil to emerge later as adults. Adult beetles survive the winter among the clustering honey bees.
Control Strategies: Two products are currently available for control of small hive beetle in Tennessee. Gardstar (40% permethrin, Y-Tex Corp. Cody, WY ) was registered in the US in 1999 to be used as a soil drench under and around bee colonies to kill beetle pupae and interrupt the life cycle. The drench should be used in abandoned apiary sites where beetles have been found. Label directions should be followed when using this or any chemical for pest control.
An emergency-use (Section 18) registration was granted by the EPA for many states including Tennessee to use Check Mite+ (10% coumaphos, Bayer Corp., Shawnee, KS) as an in- hive treatment to kill beetles inside the honey bee colony. This material cannot be used when bee colonies are producing honey. Chemical resistant plastic gloves (eg. Nitrile) must be used when handling the chemically impregnated strips. To apply CheckMite+ a strip is cut in two equal parts horizontally, stapled to the underside of a piece of corrugated cardboard (4 in x 4 in) that has been stripped to expose the corrugations. Place the cardboard (plus CheckMite+) on the colony bottom board for at least 3 days and no longer than 45 days.
The small hive beetle is suspected to be a problem around honey houses. Therefore, immediately extract comb containing honey after being removed from the colony. Improve sanitation around honey houses by cleaning up unprotected comb, wax cappings, slumgum and spilled honey.
Research is currently being conducted to develop traps to effectively detect beetles and improve current control strategies.
Please notify this office or Dr. Ray McDonnell, State Apiarist of the Tennessee Department of Agriculture (865-594-6098) if any suspect beetles are located.