Fusion_power
Field Bee
- Joined
- Jan 13, 2016
- Messages
- 774
- Reaction score
- 82
- Location
- Hamilton, AL U.S.A.
- Hive Type
- Other
- Number of Hives
- 24
I'm writing this to give some hands on experience working bees in an area that has hive beetles (Aethina Tumida). I am in Northwest Alabama, U.S.A. which is roughly at the same latitude as Morocco, Africa. My climate is temperate with winter lows around -10C and summer highs near 45C. Spring pollen is usually available the second week of February with a major flow starting about April 20th and lasting until June 1st. June is sporadic with minor flows that rarely produce a surplus. July and August give a nectar dearth but with some pollen available from maize and other plants. Goldenrod blooms in late September followed by aster. We don't normally get a surplus from the fall blooms, but there is usually enough to tide the bees over to next spring.
Hive beetles are a nuisance most times of the year but can become invasive from roughly July through October. They will be present in a hive hiding in cracks and crevices where the bees can't get to them. They have been present in this area for about 10 years but did not cause much trouble until this year. What changed? There has been an explosion of both wax moths and hive beetles in this area. I suspect a beekeeper let several colonies get weak and the hive beetles and wax moths then destroyed the colonies and moved on to other beekeeper's colonies. We also had a very mild winter which suggests warmer winters are favorable to beetle growth and survival.
What do I mean by an "explosion" of moths and beetles? I went out behind my house a few weeks ago about 10:00 pm at night. My house has a rear roof overhang that covers roughly a 3 X 5 meter area. That area was so covered in wax moths that the wall and roof were a pulsing mass of moths. I estimate their numbers in the tens of thousands. Other beekeepers in this area have reported similar experiences. Hive beetles began showing up in my hives by the hundreds about 6 weeks ago. It is impossible to open a hive without finding a few hundred beetles hiding under the edge of the cover or in the rebate where the frame ears rest. This is a major difference from previous years when beetles rarely were above 100 in a hive.
Beetles are opportunist invaders. They wait until the hive is disrupted, then lay several thousands of eggs that hatch into slime spreading larvae. The larvae preferentially feed on sealed brood and pollen in and near the brood nest. They don't feed directly on honey, but will slime the surface of sealed combs. When they are through, the combs are coated with slime and covered in beetle pheromones.
What works to keep beetles under control? Beetle traps have been designed to let the beetles crawl in where they are exposed to various killing materials such as vegetable oil, diatomaceous earth, or chemicals such as fipronil which is deadly to bees. A piece of cardboard cut so the holes are exposed can be used as a beetle trap. The beetles will crawl into the ribs of the cardboard which can then be removed and burned.
Some bees express resistance to hive beetles. The behavior I've seen is for a bee to grab a beetle and buzz wings to spin rapidly while trying to sting the beetle. This trait tends to be variably expressed in my bees suggesting that selection for enhanced resistance is feasible. Beetles tend to run out the entrance and fly away if aggressively pursued by bees.
The beekeeper can take several steps to prevent beetle damage. The first is to maintain queenright healthy colonies, especially from mid-year through November. A colony that goes queenless will be ok for about 3 to 4 weeks until all brood has hatched. They will at some point produce laying workers which will provide a brood area for the beetles to lay eggs. From the first beetle egg laying until total slime out takes about 2 weeks.
Another very helpful measure is to remove all honey promptly and get it extracted and combs placed into storage. Beetles are not attracted to stored combs that have not been used to produce brood. Bees should be maintained on the number of combs they can cover. My colonies currently average covering about 5 or 6 Dadant size frames. I cut them all down to this size using dividers and placing removed combs into protected storage. Leaving empty areas in the hive are not a problem so long as there is no nectar flow. A frame or two of foundation can be placed in the hive if the bees are likely to need it for storage.
Keep the hive floor clean. Check the hive regularly and if any debris has built up, remove it. Beetles will lay eggs in hive debris, then the beetle larvae will crawl up onto the combs to feed.
If you find a slimed out hive, do something about the combs promptly. I've been placing them into a strong plastic bag and freezing them for a week to kill the larvae and eggs. This interrupts reproduction which cuts down the number of beetles next year.
Be very careful if raising queens. A weak mating nuc or any "disrupted" hive is a candidate for beetle invasion. I've found that making up mating nucs with 3 full size frames of bees and brood is sufficient to prevent problems. This is much more bees and brood than most queen producers can spare! This is during my seasonal dearth so splitting a dozen colonies into 20 or 30 nucs does not cost my honey crop.
Hive beetles are a nuisance most times of the year but can become invasive from roughly July through October. They will be present in a hive hiding in cracks and crevices where the bees can't get to them. They have been present in this area for about 10 years but did not cause much trouble until this year. What changed? There has been an explosion of both wax moths and hive beetles in this area. I suspect a beekeeper let several colonies get weak and the hive beetles and wax moths then destroyed the colonies and moved on to other beekeeper's colonies. We also had a very mild winter which suggests warmer winters are favorable to beetle growth and survival.
What do I mean by an "explosion" of moths and beetles? I went out behind my house a few weeks ago about 10:00 pm at night. My house has a rear roof overhang that covers roughly a 3 X 5 meter area. That area was so covered in wax moths that the wall and roof were a pulsing mass of moths. I estimate their numbers in the tens of thousands. Other beekeepers in this area have reported similar experiences. Hive beetles began showing up in my hives by the hundreds about 6 weeks ago. It is impossible to open a hive without finding a few hundred beetles hiding under the edge of the cover or in the rebate where the frame ears rest. This is a major difference from previous years when beetles rarely were above 100 in a hive.
Beetles are opportunist invaders. They wait until the hive is disrupted, then lay several thousands of eggs that hatch into slime spreading larvae. The larvae preferentially feed on sealed brood and pollen in and near the brood nest. They don't feed directly on honey, but will slime the surface of sealed combs. When they are through, the combs are coated with slime and covered in beetle pheromones.
What works to keep beetles under control? Beetle traps have been designed to let the beetles crawl in where they are exposed to various killing materials such as vegetable oil, diatomaceous earth, or chemicals such as fipronil which is deadly to bees. A piece of cardboard cut so the holes are exposed can be used as a beetle trap. The beetles will crawl into the ribs of the cardboard which can then be removed and burned.
Some bees express resistance to hive beetles. The behavior I've seen is for a bee to grab a beetle and buzz wings to spin rapidly while trying to sting the beetle. This trait tends to be variably expressed in my bees suggesting that selection for enhanced resistance is feasible. Beetles tend to run out the entrance and fly away if aggressively pursued by bees.
The beekeeper can take several steps to prevent beetle damage. The first is to maintain queenright healthy colonies, especially from mid-year through November. A colony that goes queenless will be ok for about 3 to 4 weeks until all brood has hatched. They will at some point produce laying workers which will provide a brood area for the beetles to lay eggs. From the first beetle egg laying until total slime out takes about 2 weeks.
Another very helpful measure is to remove all honey promptly and get it extracted and combs placed into storage. Beetles are not attracted to stored combs that have not been used to produce brood. Bees should be maintained on the number of combs they can cover. My colonies currently average covering about 5 or 6 Dadant size frames. I cut them all down to this size using dividers and placing removed combs into protected storage. Leaving empty areas in the hive are not a problem so long as there is no nectar flow. A frame or two of foundation can be placed in the hive if the bees are likely to need it for storage.
Keep the hive floor clean. Check the hive regularly and if any debris has built up, remove it. Beetles will lay eggs in hive debris, then the beetle larvae will crawl up onto the combs to feed.
If you find a slimed out hive, do something about the combs promptly. I've been placing them into a strong plastic bag and freezing them for a week to kill the larvae and eggs. This interrupts reproduction which cuts down the number of beetles next year.
Be very careful if raising queens. A weak mating nuc or any "disrupted" hive is a candidate for beetle invasion. I've found that making up mating nucs with 3 full size frames of bees and brood is sufficient to prevent problems. This is much more bees and brood than most queen producers can spare! This is during my seasonal dearth so splitting a dozen colonies into 20 or 30 nucs does not cost my honey crop.