OSU Honey Bee Lab

The Small Hive Beetle (SHB; Aethinatumida murray) is the newest bee hive pests to invade some honey bee colonies in various Southeastern, Midwestern, and Northeastern states. The SHB appears to be primarily a pest of stored equipment—especially full honey supers awaiting extraction. In states where the beetle has become established, it has proved to be a problem in some areas while being of little consequence in other areas within the same state.

Many beekeepers are using the Varroa mite introduction experience as a protocol for the arrival of the SHB. So far, this has not been the case. Though the beetles, under specific conditions, can be very destructive, they have not proven to be anywhere as serious as the Varroa mite.

The Small Hive Beetles' Life Cycle

What they look like

The adult SHB beetle is dark brown to black and about one third the size of a worker bee. Larvae are elongated, whitish grubs that have three pairs of legs and can be mistaken for wax moth larvae. However, SHB larvae do not spin cocoons and must complete their development outside the bee hive in the soil. In severe infestations, larvae may be seen crawling out of the hive entrance or from stored honey supers.

Eggs to adult within 45 days

Figure 1. The Adult and larval stage of the Small Hive Beetle. (Adult ³/₈" in length)

Beetles, like moths and bees, undergo complete metamorphosis. The beetles' life cycle starts with eggs which are laid in the hive and within two to three days hatch into larvae. Ten to sixteen days later, the larvae crawl from the hive and drop to the ground outside, where they burrow into the soil and pupate. In about three to four weeks they emerge as adult beetles and re-enter the hive a week later. This process may repeat itself several times a year, especially during the warmer months.

Bees abandon the hive

Colony damage does not occur when only a few adult beetles are present in the colony. The SHB must build up its population significantly before it can take over and destroy a hive. The beetles, in their various development stages, feed on honey and pollen in the hive, foul the honey, and destroy the comb and bee brood. The beetles' armor resists attempts by bees to sting them. The destruction eventually causes the bees to leave the hive.

Honey destruction

Because they defecate in the honey and the resulting fermentation and odor make it unattractive to the bees, larvae of the SHB are most objectionable to adult bees. The SHB larvae also damage wax honey combs — especially newly drawn, delicate combs. When wax combs stand for a few days to a few weeks in the honey house, ready to be extracted, beetle larvae infestation can be most troublesome. This damage to honey combs happens when beetles are actively reproducing in the colony and are taken into the honey house.

Finding the Beetle in the Hive

Figure 2. An adult Small Hive Beetle on a screen inner cover.

Beekeepers are urged to call the Ohio Department of Agriculture at (800) 282-1955 if they suspect their colonies are infested by the SHB. Also, all beekeepers should check their colonies at least monthly—especially beekeepers who have purchased packaged bees from outside Ohio.

Difficulty in Finding the Small Hive Beetle

Looking for SHB in a colony may be difficult—the adult beetle is dark-colored, moves fast, and avoids light. Beetles are likely to be found in crevices in the hive or on the bottom board—although when temperatures are cooler, the beetles remain with the bee cluster and do not move onto the bottom board. Many times when separating a hive consisting of two deep hive bodies, the beetle may be found along the frame rest grooves.

Follow these steps

Figure 3. A deep hive body positioned on an outer cover. If present, adult beetles can be seen crawling in the outer cover.

A simple technique used to look for beetles in bee colonies is to remove the outer cover, place the cover upside down on the ground, remove the deep super, or brood chamber, and place on the up-turned outer cover. If beetle are present, they will move out of the super away from the light and into the outer cover, and may be seen crawling in the cover.

How to Rid Hives of the Small Hive Beetle

Diagnose properly

Preventative use of unapproved insecticides in and around bee hives is potentially risky and is not recommended. Beekeepers should become familiar with the SHB in order to properly diagnose and manage the beetle should it occur. Populations of the SHB are known to be established in Georgia, Florida, and South Carolina. Sound pest management begins with positive diagnosis of the pest. Again, for verification of suspected SHB, call: (800) 282-1955.

Good hive management

There are several colony management tools, which are effective against infestations when integrated with the use of available insecticides. They are:

1. Maintain a strong bee population in each hive.
2. Inspect every hive at least once a month.
3. Moving the hive will disrupt the life cycle of the beetle.
4. Maintain close mowing or bare ground around the hive to facilitate chemical controls and provide less shelter for beetle larvae leaving the hive to pupate.

Chemical controls

A pesticide selected for application within or around a bee hive must have usage directions specifically for the control of hive beetles. To protect themselves, their bee colonies, and the honey, beekeepers must read and follow all use precautions on the pesticide label.

Pesticide treatment inside the hive

An emergency exemption has been approved by the US Environmental Protection Agency (EPA) for beekeepers to use pest control strips containing the chemical "coumophos." The strips can be used in Alabama under the trade name CheckMite+ Bee Hive Pest Control Strip. The insecticide is impregnated into a plastic strip which is placed in the bottom of the hive body. There, the beetles absorb a lethal dose of insecticide when they contact the strip.

Basic Precautions for Using CheckMite+

Figure 4. Paint paddle attached to a corrugated board with CheckMite+ strips attached.

CheckMite+ can be used for control of Varroa mites, but the use directions are very different for control of the hive beetle — such as when and where the chemical should be applied and how long the treatment should last. For example, CheckMite+ strips should be placed in the hive for no more than seven days at a time when treating for the beetle. A hive should be treated with this pesticide no more than four times per year. A hive, having honey destined for human consumption, should not be treated with any chemical including CheckMite+. Specifically, honey supers must not be on the hive during treatment (whether for SHB or Varroa) to avoid this pesticide coming in contact with honey intended for human food. Coumaphos works better when the air temperature is over 70° F. Complete use directions are listed on the product label.

Prepare a piece of corrugated cardboard box, approximately four inches by four inches, by removing one side, thereby leaving a series of paper ridges. Remove a CheckMite+ strip from the original packaging and cut the strip in half across the center. Staple the CheckMite+ strip halves to the ridged side of the four inch by four inch corrugated cardboard. Place this cardboard as close to the center of the bottom board as possible, with the strips facing down. Leave the card board and strips on the bottom board for at least three days, but not more than the time specified on the label. For convenience of installation, a paint paddle can be stapled to the cardboard. Again, always follow directions as listed on the product label. Beetles will crawl beneath the cardboard into the paper ridges to hide and will be exposed to the chemical coumaphos.

Pesticide treatment outside the hive

Beekeepers will also want to exploit a vulnerable point of the beetles' life cycle, when mature larvae enter the soil near the hive to pupate, GardStar 40% EC is a concentrated formulation containing the insecticide permethrin and is commonly used to control fire ants. This product is directed at control of the hive beetle larvae — it kills the larvae when they come into contact with insecticide-treated solid near the hive.

Basic precautions for Using GardStar 40% EC

GardStar 40% EC poses a higher risk to bees and humans than does CheckMite+. Follow these instructions: Permethrin is highly toxic to bees, so beekeepers must use extra caution when applying it around a bee hive. If a hive is SHB-infested, here are two ways to approach the problem.

1. Moving a hive to a site where GardStar 40% EC has been previously applied should reduce potential insecticide exposure to bees.
2. Dilute GardStar 40% EC in water and apply to soil in front of the hive using a sprinkling can or low-pressure sprayer – even small amounts of pesticide spilled or sprayed onto the hive can be dangerous to bees. Caution: GardStar 40% EC in concentrated from can cause irreversible eye damage if splashed in the eye. Wear a face shield or safety glasses when mixing concentrate from the original container.

General Overview Comments

CheckMite+ has only been given a temporary use permit. The future use of this product as a control material for the SHB is not guaranteed.

Additionally, there are reports that the SHB has been found in Bumble Bee nests. These reports will need to be confirmed this season. If, in fact, the SHB is found in bumble bee nests, the overall seriousness of these beetles will greatly increase. Since bumble bees are not maintained in artificial domiciles (hives), the effects of these beetles could threaten the bumble bee population making pollination even more of an issue. At this time, these reports are not confirmed.

Acknowledgments

The information in this brochure was predominantly compiled by the Ohio Department of Agriculture in cooperation with Ohio State University Extension and the Ohio Department of Agriculture.

Dr. James E. Tew State Specialist, Beekeeping The Ohio State University