Hornet control

[Chiangmai member]

Its been a long wet season here in Chiangmai, Thailand and there have been large numbers of hornets, esp. Vespa velutina this year. This is the hornet species that is an invasive species in France and is threatening to invade the UK. Its feeding behaviour is to hover in front of the hive entrance and catch returning workers. You can see how they do this on Youtube videos, (search for frelon asiatique). Apis mellifera has only been in Thailand for 50 odd years and has not yet developed any defence against velutina, which is wonderfully well adapted to hunting bees.

One velutina hornet can take up to 30 bees a day, apparently. A few weeks ago, a friend of ours in ChiangDao killed 800 hornets in one morning! Since May, I estimate that we have lost around 50% of our bees to them. The result being that when the rains stop next month and the winter flower nectar flow starts, we will not have enough bees.

We have tried different ways of detering them. Swotting with badminton rackets is effective but brainless. Inverted bottle traps baited with sugar solution or pork catch a few but not enough to reduce pressure on the hives. Reducing the entrance spaces seems to make it even easier for them. Finding the nests is impossible in a suburban environment with modern housing providing many well protected nesting sites.

So heres a challenge. Does anyone have an idea that might deter this pest? The pre-conditions being that the idea can't be labour intensive and it can't involve poisons. Perhaps someone in France has come up with a smart way of detering them. At this stage, any ideas, even crazy ones are welcome.

 

[ratcatcher]

stick me on the crazy list, I stood by my hives blasting them with the 410 shotgun

http://youtu.be/WINE-0GeliE

 

[Torq]

Is it the Asian hornet or the GIANT Asian hornet that is attacking your hives?

 

[wessexmario]

At this stage, any ideas, even crazy ones are welcome.

are they much bigger than the bees?
If so then would a mesh box in front of the hive entrance keep them away from the hive? with a mesh size that the bees can get through but the hornets not.

"Insect prey is usually caught on the wing, with the Asian hornet hovering over the entrance to a hive and catching foraging honey bees returning with nectar or pollen. The hornet forces its prey to drop to the ground before paralysing it and carrying it away"

If the french hornets use the same tactics as the asian ones, how about a couple of horizontal boards in front of the hive?
The bees could fly through, but the boards would disrupt the dive-bombing technique of the hornets.

 

[Torq]

A dartington style floor with a wire queen excluder across the front should keep them out. Youtube has videos of plenty of wire traps that fit to the front of the hive but these seem to be primarily aimed at the giant Asian hornet.

I'm still not convinced that they will colonise these Islands to any great extent. The European hornet is not widespread across the UK and are nonexistent in Ireland. I have a feeling (hope) that they may not be suited to our climate. But I guess that only time will tell and just like in 1066 they will probably invade from Normandy.

 

[Roola]

Chiangmai member, I'm coming travelling to Thailand next month and will be in Chiangmai, do you think there is any way I could pop in and visit? I'd love to see beekeeping in another country and I can get a bee fix whilst I'm away. I know it's cheeky but let me know if it's possible.


Sent from my iPad using Tapatalk

 

[Heffy]

Hey All

As we are brain storming for solutions.

Is there anything that eats hornets and not bees ? Maybe unlikely.

Cheers
Matt

 

[ratcatcher]

I thought about the pane of glass idea, but these were flying around the hives picking off straggles, the guard bees were all on the entrance, but one even landed on that, picked up a bee, dropped to the ground and killed it, before settling on a nearby branch, BANG!!!!! went the gun

 

[Erichalfbee]

Vita have invented a hornet trap. Looks easy to copy if you are handy
Have a look here
http://www.vita-europe.com/news/asian-hornet-trap-launched-combat-latest-honeybee-pest/

 

[MuswellMetro]

A dartington style floor with a wire queen excluder across the front should keep them out. Youtube has videos of plenty of wire traps that fit to the front of the hive but these seem to be primarily aimed at the giant Asian hornet.

I'm still not convinced that they will colonise these Islands to any great extent. The European hornet is not widespread across the UK and are nonexistent in Ireland. I have a feeling (hope) that they may not be suited to our climate. But I guess that only time will tell and just like in 1066 they will probably invade from Normandy.

see pdf of a science paper on were the climate is suitable for the Asian Hornet

The englargement of the maps of possible area shows the SW is likely to be a hotspot but ireland does not escape

 

[Torq]

That was an interesting read! But I'm still none the wiser as to why the European hornet does not cover the whole of the UK mainland. Is it native or invasive? If invasive when did it arrive and what has stopped it's spread?

 

[Chiangmai member]

Thanks for all the ideas. In response:

Torq: The hornet species that we have the problem with in Thailand is Vespa velutina but not the sub-species Vespa velutina nigrithorax which is causing the problems in France, Spain and Italy.

Torq & Wessexmario. The hornet is bigger than the A meliffera but smaller than the European hornet. We are experimenting with mesh cages but the problem is not the hornets getting into the hives, it’s the hawking of returning bees that reduces bee populations and deters bees from foraging. If one puts a cage or screen at the entrance, the hornets just hover outside it and pick off bees as they try and negotiate their way through the mesh. If anything it makes it easier for them. What we need is for a way for the returning workers to enter the hive as quickly as possible.

Roola: More than happy to show you around some apiaries in Chiangmai. Call me on 0849503740, when you arrive in Thailand or you can email me on [email protected]

Heffy. Good question but so far all I can find are bee eaters and drongos both of which like bees

Ratcatcher: will try and pane of glass idea, which may work as the hornets hunt by sight and it may confuse them to an extent.

Erichalfbee: Yes I’ve seen the Vita trap but I don't think its going to stop the hornets from bee hawking.

Muswelmetro: Thanks very much for the paper. I had not seen it and it looks a good read.

One other idea perhaps worth pursuing is to use extracts from flowers of the Dendrobium sinense orchid in traps to attract hornets. This orchid, native to Taiwan, mimics the alarm pheromone of bees to attract hornets for pollination purposes.

Thanks again for all the ideas.

 

[Gilberdyke John]

Thanks for all the ideas. In response:

Torq: The hornet species that we have the problem with in Thailand is Vespa velutina but not the sub-species Vespa velutina nigrithorax which is causing the problems in France, Spain and Italy.

Torq & Wessexmario. The hornet is bigger than the A meliffera but smaller than the European hornet. We are experimenting with mesh cages but the problem is not the hornets getting into the hives, it’s the hawking of returning bees that reduces bee populations and deters bees from foraging. If one puts a cage or screen at the entrance, the hornets just hover outside it and pick off bees as they try and negotiate their way through the mesh. If anything it makes it easier for them. What we need is for a way for the returning workers to enter the hive as quickly as possible.

Roola: More than happy to show you around some apiaries in Chiangmai. Call me on 0849503740, when you arrive in Thailand or you can email me on [email protected]

Heffy. Good question but so far all I can find are bee eaters and drongos both of which like bees

Ratcatcher: will try and pane of glass idea, which may work as the hornets hunt by sight and it may confuse them to an extent.

Erichalfbee: Yes I’ve seen the Vita trap but I don't think its going to stop the hornets from bee hawking.

Muswelmetro: Thanks very much for the paper. I had not seen it and it looks a good read.

One other idea perhaps worth pursuing is to use extracts from flowers of the Dendrobium sinense orchid in traps to attract hornets. This orchid, native to Taiwan, mimics the alarm pheromone of bees to attract hornets for pollination purposes.

Thanks again for all the ideas.

Since the hornets are taking protein is there some poison that could be applied to bait which the hunters could take home to their nests? Nippon ant killer used to be available in the uk for domestic use and would clear an ant problem in a few days. It seems to have much less potency nowadays which I put down to EU or H&S rules but you may not be afflicted by the same beauracracy.

 

[dclewis]

Simple bottle traps are used extensively this side of the Channel, bates used change with the season, but are basically a mix of beer, cheap plonk, and blackcurrent or other sweet fruit juice. Recently there was an article in the French bee mag regarding the use of a sort of electric fence arrangement placed close to the hives but I have not seen either how effective or what it costs, but its got to be a lot more than the simple bottle traps. See utube if you look up:
Film Montage harpe Apiprotection

 

[ratcatcher]

Since the hornets are taking protein is there some poison that could be applied to bait.

but what about non target species???? if a hornet can get in, then so could all other insects of the same size or smaller

 

[Bosleeu]

If they come to the UK, we can catch a few live ones, anaesthetise them with CO2,and fit them with those little trackers they used in the BBC beekeeping program. After they wake up we can release them, track them to their nests, and destroy them.

 

[Chiangmai member]

Out of desperation, we have been trying something new. An experienced local beekeeper told us that the way to reduce hornet predation on bees is to catch 20 live hornets that are visiting your bees, put them in a jar and dust them liberally with the insecticide Sevin, (Carbaryl (1-naphthyl methylcarbamate)). Then let them go; The idea being that the hornets will then take the insecticide back to their nests.

Sevin is a fine white powder and the hornets are completely white when they fly off. The dusting process kills some of the hornets but at least 50% of them fly off in a way that suggests they want to get home quickly. As hornets are social insects its possible that on reaching the colony, other hornets groom the contaminated one and in this way the insecticide is spread through the colony.

We are porbably too late to have much of an effect this year but this technique could be useful at the start of the wet season, when hornet colonies are small. Today there are no hornets on our bees but that may be because its the end of the period when they need bee protein to raise brood and new queens. Or maybe.......?

I am not a fan of insecticides. (I run a small organic farm north of chiangmai) but I must say that I like the idea of the precise targeting of offending hornet nests that this technique allows for.

Carbyl is banned in the UK but is used extensively in the US and seems to be permitted in France.

 

[dclewis]

With this lovely weather we have been having this September the European hornets are continuing to raise brood and are increasing their predation on my bees in the apiary at the moment. Anything up to a dozen flying around the hives at any one time, so the traps are out. The Asian hornets are now in the department but have yet to see one in my neck of the woods.