This is a revised version of my 1999 article. I have seen the adult beetles in colonies again, and imagine some of you might have questions for this pest.
The small hive beetle, Aethina tumida Murray, was a new pest attacking honey bees and hives in US since 1998. Its native range is sub-Saharan Africa; where it is considered minor in its effects, attacking weakened colonies and combs in storage and treatment is seldom necessary. In the following I will discuss briefly its morphology, distribution, biology and control.
1. Classification and morphology: This critter is a member of the beetle family Nitidulidae, which are mostly scavengers (such as sap beetles, strawberry beetles). Adult beetles are about 5-7 mm long, dark brown to nearly black, with clubbed antennae. Move fast and play dead when touched. Larvae are white grubs that can be easily confused with waxmoth larvae, but they move differently (waxmoth larvae tend to undulate while beetle larvae do not). A photo of small hive beetle larva can be seen here.
2. Distribution: SHB is first reported in May 1998 in Florida. It had been in South Carolina for at least a few years before its official discovery. It probably came with bees from a ship from South Africa. Right now it is established in Florida, South and North Carolina, Georgia and Ohio. It has been reported in Minnesota, Wisconsin, Michigan but probably not established yet in these States yet. In Michigan, the beetles seem to be mostly confined to a honey house in SW Michigan. No larvae or adults were found in the 10 apiaries when I checked with a beekeeper during September. Updated distribution map is available at http://ceris.purdue.edu/napis/pests/shb/imap/shball.html.
3. Biology. Adult beetles find honey bee colonies (probably by smell), invade, and lay eggs inside. Both larvae and adults feed on brood, pollen, wax, honey, and damage brood and honeycomb. Larvae would leave slime and bad odor behind so bees would simply abandon the comb or the entire colony. Mature larvae are attracted to light and enter soil to pupate. The duration from egg to adult is abut 38-81 days in Africa and probably similar in Florida. Adults can fly up to 15 miles to find a colony. They can live for about 6 months. It has been shown that they can complete development (egg to adult) on rotten fruits such as cantaloupe and strawberry. Larvae must enter the soil to pupate. Adults emerge and fly to a colony of bees where it takes up residence.
4. Control. The most critical thing is early detection. Check your colonies carefully when you are working with them, pay special attention to top inner cover and bottom board for beetles. Collect them and send them to me (517-353-8136) or Mike Hansen (616-428 2575) for identification. Once positively identified, you can purchase CheckMite+ (also called Bayer Bee Strips, active ingredient is coumophos) from Mann Lake Ltd (1-800-233-6663 ). Michigan has obtained a section 18 (emergency registration) for the use of this pesticide, thanks for the effort by MDA. To use the CheckMite+ strips, prepare a piece of corrugated cardboard (4×4″) and remove the cover of one side to expose the corrugation. Cut a strip in two and staple them to the exposed side of the cardboard and place it near the center of the broom board with the strips down. SHB are attracted to the cardboard as a hiding place and are then killed by contact with the coumophos strip. Treat for 3 – 45 days. It is not recommended to treat more than 4 times per year to prevent resistance from building up. This method probably works only when beetles just recently invaded the colony and have not started laying yet. Larvae would remain in the frames, and not have a chance to reach the cardboard trap, and would not be killed.
Soil treatment would complement the above method since larvae will be killed when trying to enter soil to pupate. GardStar (contains 40% permethrin) can be used for SHB and is available from Blossomland Supply (616-473-3917) or other stores selling cattle pesticides. Use 5 ml of GardStar per liter (0.05% active ingredient) and spray the area underneath the hive and at least 1 ft in the periphery of each direction. If you bring bees from the states where the beetles have established, you should treat the soil before placing the colonies. It is not clear how long the pesticide would stay active in the soil before re-applying is needed.
Right now most damages seem to be in the honeyhouses. We can no longer let honey supers stay for a month before extracting if we have beetles. Extract promptly (within one week), keep the honey house clean, and fumigate the extracted supers before storage or putting them back to the colonies.
6. Outlook for Michigan: The beetle has been here for about 11 years and I have not seen any huge damages in Michigan yet, other than in honey houses. It will only attack weak colonies and/or frames in storage. Beetles will not overwinter in unheated honey houses, but can survive in winter cluster with the bees.
Zachary Huang, Michigan State University
Can they be treated in Sept and Oct in Michigan?
I would say treat now, if you find something. But probably not necessary if anything is found after Oct 15th…the weather will take care of the larvae in the colony, or pupae in the soil. Zachary Huang
Small Hive beetles on Belle Isle
Somehow the Small Hive Beetles have crossed the Detroit River and attacked my two colonies at the back of the belle Isle nature Zoo. so far, no beetles in the three-frame glass observation hive in the Nature Center.
Am using Beetle Blaster type plastic traps and they do catch a number of the beetles, which go through the grid and drown in the salad oil below.
Found several dozen adult beetles in each colony which seem to be reducing in number fast.
Justwhat we need: Another nasty pest attacking our bees!
Steve Burt
Good to hear about Belle Isle bees sleeping with oil as opposed to pesticides. I found a few beetles in two of my hives downtown Detroit. I got a bottom board oil trap from greenhives.com, and caught several beetles and a few larvae. Then I even looked through the whole hive frame by frame and saw no beetles or larvae left. I’m sure it’s not the end of it though.
Belle Isle Update
Between the Beetle Blaster traps and just killing them by hand as we go through the coonies, we have probably killed about 200 beetles in the last six weeks, here at the Belle Isle Nature Zoo. I have not found them yet damaging the combs and honey, and each colony is decently strong for late fall.
I have none so far in my Roseville apiary (Masonic/Beaconsfield area). Four nice, strong colonies there, ready for winter.
In addition to traps, we plan in the spring to install heavy blue or black plastic tarp (12 x 12 feet for a start) on top of the soil under the apiary at Belle Isle for a pupiation barrier.
We are leery of Guardstar or putting past strips within the colonies at an ecologically sensitive site, and I want to be able to continue to produce pure, “Belle Isle” honey, knowing it is as truly as pure as possible. In five years we have never medicated these bees at all and our losses have been <20% in spite of a small but stubborn mite population (Russian/Italian hybrids and screened bottom boards year round).
-Steve Burt
I found SHB in my only colony in March 2011. Had to spend time to find out what they were. I put in a “beetle blaster” in April. It has just been too cold to take the hive apart. I was thinking I would take the lower super out and check out the beetle situation. I might just burn the old bottom board put in a new one and potentially burn the bottom super and put unaffected frames in a new super with beetle blasters or a new beetle bottom board. The colony is strong and survived the winter in good shape but I want those little monsters out of my hive. I just put in two new hives this spring. Questions: how do I eradicate the monsters and what should I do to prevent them from attacking my new hives. Suggestions would be appreciated. I don’t know how to pull the hives apart without causing major problems? Help?
Kay
Use CheckMite+ strips: “To use the CheckMite+ strips, prepare a piece of corrugated cardboard (4×4″) and remove the cover of one side to expose the corrugation. Cut a strip in two and staple them to the exposed side of the cardboard and place it near the center of the broom board with the strips down. SHB are attracted to the cardboard as a hiding place and are then killed by contact with the coumophos strip.”
No need to burn your equipment as the beetles are large can be easily found, unlike spores of AFB or Nosema.
My friend west of Ann Arbor had small hive beetle invade three of his four hives in July 2011.