Asian Hornets

[Erichalfbee]

Which reminded me of this text from the AHAT website:

"Asian hornets can fly at approximately 3 metres per second. In comparison, the normal top speed of a honey bee would be about 21-28 km per hour when flying to a food source and about 17 km per hour when returning lladen down with nectar and pollen."

I don't know why they've mixed up the units, but 17km/h works out as about 4.75m/s, or over half as fast again as AH, which makes me wonder what point they're trying to make.

James

No idea.
It’s pretty obvious that bees leaving the hive to forage zoom out.
Coming back they are much much slower. It’s hardly surprising.

 

[JamezF]

Talking to Jeremy Vine (not a fan so don’t shoot me but a friend messaged me to say he was doing a piece so I thought I’d listen) Simon said the hornets reduced the bees in such numbers the wasps moved in unchallenged and when the colony was wiped out Velutina moved in to take all the larvae.

That suggests to me a "rookie error".

If he knew that a number of the hives were low on numbers because of hawking by hornets, why not unite them, reduce the entrance and move them away? I'm sure that if he'd said "I'm neck-deep in AH problems and desperately need a place or two for two or three hives until the hornets die off and I can get things sorted" that someone in his local BKA would have helped out or known someone who could.

James

 

[fian]

Which reminded me of this text from the AHAT website:

"Asian hornets can fly at approximately 3 metres per second. In comparison, the normal top speed of a honey bee would be about 21-28 km per hour when flying to a food source and about 17 km per hour when returning lladen down with nectar and pollen."

I don't know why they've mixed up the units, but 17km/h works out as about 4.75m/s, or over half as fast again as AH, which makes me wonder what point they're trying to make.

James

Maybe that's why they wait for them at the entrance, that is, when the bee has to slow down to avoid crashing into the spout. Even so, the success rate of a hornet is 1 to 5 but its presence reduces recognition dances and ventilation tasks.

 

[JamezF]

It’s pretty obvious that bees leaving the hive to forage zoom out.
Coming back they are much much slower. It’s hardly surprising.

I assume AH don't actually pick them off so much until they go "flaps down" ready to stop on the landing board or hive front.

I'm vaguely aware that one of the defences against AH is to put a "mesh cage" ahead of the entrance that the bees can fly through and AH can't. I guess if it extends far enough that the bees are still at full throttle when they pass through it then perhaps that makes the hornet's life more difficult. Bonus points for electrifying the cage like a fly killer

James

 

[jenkinsbrynmair]

I'm vaguely aware that one of the defences against AH is to put a "mesh cage" ahead of the entrance that the bees can fly through and AH can't.

Another wrinkle I read was to leave the area in front of the hive get overgrown so the bees could fly through the foliage but the AH would have problems picking them off.

 

[fian]

I assume AH don't actually pick them off so much until they go "flaps down" ready to stop on the landing board or hive front.

I'm vaguely aware that one of the defences against AH is to put a "mesh cage" ahead of the entrance that the bees can fly through and AH can't. I guess if it extends far enough that the bees are still at full throttle when they pass through it then perhaps that makes the hornet's life more difficult. Bonus points for electrifying the cage like a fly killer

James

Yes, we already know mesh boxes, and also electric harps as protection methods.

 

[JamezF]

Several claims of AH in south-east Somerset today it seems. I'm doubtful. I suspect they'll be V. crabro. I had six (of the latter) tapping on the window outside my office wanting to be let in yesterday evening.

James

 

[The Poot]

I wondered how honeybees in Asia cope with the hornet and I found a report that stated the bees strategy is to fly at full speed into the hive, unlike our bees that throttle back. I’m wondering if modified entrances would help - but how? Bigger to allow full speed in, but it would allow wasps entry too! The hornets don’t generally enter the hives that are strongly defended.It’s a bit of a conundrum.

 

[JamezF]

I wondered how honeybees in Asia cope with the hornet and I found a report that stated the bees strategy is to fly at full speed into the hive, unlike our bees that throttle back. I’m wondering if modified entrances would help - but how? Bigger to allow full speed in, but it would allow wasps entry too! The hornets don’t generally enter the hives that are strongly defended.It’s a bit of a conundrum.

UFE with the entrance slot in the middle rather than towards the front, perhaps? Have the "landing board" slope upwards so the space available for hornets gets smaller as they go deeper? Or extend the UFE landing area forward of the hive, perhaps? Make the top from perspex so you can still watch them come and go Experimentation would be required I think.

James

 

[The Poot]

UFE with the entrance slot in the middle rather than towards the front, perhaps? Have the "landing board" slope upwards so the space available for hornets gets smaller as they go deeper? Or extend the UFE landing area forward of the hive, perhaps? Make the top from perspex so you can still watch them come and go Experimentation would be required I think.

James

I guess the French have tried many ideas, but I think this needs the attention of an Englishman in his shed……

 

[North End Bees]

Simon said the hornets reduced the bees in such numbers the wasps moved in unchallenged and when the colony was wiped out Velutina moved in to take all the larvae.
I still can’t understand why there is this single reported incident of carnage and no other.

I think it's really unfortunate that Simon has apparently become the unofficial spokesman for the AH experience in Kent, for the BBC at least.

Not only are his personal losses detracting from the overall seriousness of the situation but he is unintentionally muddying the waters with his facts about AH predation in general.

He said in the interview that AH take 40-60% of foragers and then local wasps come in to finish off the hive. (Despite the fact that he's actually a pest controller by profession and said he had wasp control measures on all his hives.)

Findings in France (53 mins in in the Andrew Durham video) showed that there is a 40-60% reduction of foragers actually going out when AH hawk the hives (not eaten, they're staying at home.) Foraging paralysis quickly follows and, with no food coming in, the colony starves.

Simon said he'd been monitoring the hives frequently but somehow didn't check on any colony's stores?

In France absconding is not unusual when the colony gets to this point but apparently none of Simon's absconded but were finished off by the hornets coming in to eat the remaining brood.
Why didn't he move the hives before they got to this point? AH generally forages 700m max. He could have left an empty bait hive same as you'd do with a hive being predated by wasps.

Personally, I think his losses of 14/17 hives is due to his own management and isn't reflected generally. But the sensationalism of this particular instance unfortunately results in scepticism of the genuine threat of AH to us all.

 

[Karol]

Talking to Jeremy Vine (not a fan so don’t shoot me but a friend messaged me to say he was doing a piece so I thought I’d listen) Simon said the hornets reduced the bees in such numbers the wasps moved in unchallenged and when the colony was wiped out Velutina moved in to take all the larvae.
I still can’t understand why there is this single reported incident of carnage and no other.

The hornet lifecycle generally lags that of wasps because it is a top predator. More likely wasps in sweet feeding mode overwhelmed the bee hives going after honey and lack of bee husbandry experience allowed frenzied feeding to occur which is driven by distress pheromones and would account for the hives 'roaring' before collapse. Roaring is a good description of the cacophony made during a frenzied wasp attack. Wasps in sweet feeding mode would have little interest in the brood. Velutina on the other hand, still in protein feeding mode, would readily accept the boon in larvae. One comfort to be drawn from this is that this is a sign that sexuals have not been released yet.
Whilst possible that Velutina destroyed the hives it's unlikely just from an understanding of numbers. A single hawking Velutina is unlikely to take more than 3 bees per hour. 40 hawking Velutinas would take something like 1400 bees in one day. 10 bee hives equates to some 200,000 bees. For that many hives to collapse in such a short time would require many hundreds of hawking hornets and if there were that many then other apiaries would more than likely also report a high level of predation.
All that said, the caveat remains that this is still conjecture.

 

[Tony Warren]

I would recommend that you all view Andrew Durhams presentation to BBKA, its on YouTube, it provides all the answers to the questions raised here. I have been to the apiary several times and witnessed what is happening. The hornets hawk the hives and catch the flying foragers, after a short while the hive is severly weakened and stops foraging. Then the wasps move in, an easy hit as the hive is weak. The brood is then taken by the hornet. The hornets then move on to the next weak target, and it repeats. The hornets then predate on the wasps. The apiary is absolutely full of wasp/hornets traps whcih catch a large number of hornets, but an insignificant number compared with the attacking force. We estimate that there are 4 hornet nests over the cliff in the area between the clifftop and the sea. It is likely a critical mass issue, the numbers of hornets, that close simply overwhelm.
As for moving the apiary, where to? How many people can move 17 colonies to another location, this is his only apiary? He has moved the last 3 hives, these are quite agressive which may be the reason they have survived, but there are hornets along the whole coast line from dover to Hythe (and probably further) so where to? As per Andrew Durhams presentation (part 2), there are preventions you can take, the best being the electric harp, but that runs in at £100+ and you then need a power supply, say leisure battery + spare for each hive etc etc, an expensive option.
The NBU are clearing the nests as there are sightings but there has until recently been very little done to bring it to the attention of the general public. We are, within our means, trying to get the message out there. Where there are no nests, eg in the Essex port towns, it could simply be that no-one is looking out for them. There have been nests all along the north kent coast, it is inconceivable that they are not in Essex on the the opposite shore.
The NBU remain very secretive about where the nests have been found, but it seems that there are new find almost daily/every other day. There have been another in Whitstable, ones in Medway, Hackney, Clapham and North Devon coast(?).

 

[North End Bees]

I would recommend that you all view Andrew Durhams presentation to BBKA, its on YouTube. I have been to the apiary several times and witnessed what is happening. The hornets hawk the hives and catch the flying foragers, after a short while the hive is severly weakened and stops foraging.

I would agree with everyone watching both of Andrew's presentations. Personally I've seen them several times over the years. He did an in-person talk for our division a few years ago (he's local to us). Always good to have a refresher!

But that still doesn't explain Simon's experience. The beekeepers in France and Jersey are not having 14/17 losses. If there are multiple nests in the area why didn't he move his colonies when the hawking started to escalate?

 

[jenkinsbrynmair]

If there are multiple nests in the area why didn't he move his colonies

if there are multiple nests in the area and clouds of hawking Velutina, why aren't the NBU all over the place? especially as these people seem to know where the nests are?

 

[ericbeaumont]

nests over the cliff in the area between the clifftop and the sea

people seem to know where the nests are

Recall reading that some of the nests are inaccessible.

 

[Parsonage Bees]

I would recommend that you all view Andrew Durhams presentation to BBKA, its on YouTube. I have been to the apiary several times and witnessed what is happening. The hornets hawk the hives and catch the flying foragers, after a short while the hive is severly weakened and stops foraging. Then the wasps move in, an easy hit as the hive is weak. The brood is then taken by the hornet. The hornets then move on to the next weak target, and it repeats. The hornets then predate on the wasps. The apiray is absolutely full of wasp/hornets traps whcih catch a large number of hornets, but an insignificant number compared with the attacking force. We estimate that there are 4 hornet nests over the cliff in the area between the clifftop and the sea. It is likely a critical mass issue, the numbers of hornets, that close simply overwhelm.

So now NBU is looking for a bee inspector with abseiling skills. Probably not in the job description.

Wondering just how stressed the current containment effort is. Email from our area bee inspector yesterday confirming the sighting in Hull. Another port.

 

[rolande]

I would recommend that you all view Andrew Durhams presentation to BBKA, its on YouTube. I have been to the apiary several times and witnessed what is happening. The hornets hawk the hives and catch the flying foragers, after a short while the hive is severly weakened and stops foraging. Then the wasps move in, an easy hit as the hive is weak. The brood is then taken by the hornet. The hornets then move on to the next weak target, and it repeats. The hornets then predate on the wasps. The apiray is absolutely full of wasp/hornets traps whcih catch a large number of hornets, but an insignificant number compared with the attacking force. We estimate that there are 4 hornet nests over the cliff in the area between the clifftop and the sea. It is likely a critical mass issue, the numbers of hornets, that close simply overwhelm.

What's the current situation with the remaining colonies? Are the three survivors (at time of the radio interview) still ok or have they too succumbed to the onslaught?

As someone with two clifftop apiaries the idea of AH building nests half way down the cliff face is something I've had at the back of my mind for quite some time.

 

[rolande]

So now NBU is looking for a bee inspector with abseiling skills. Probably not in the job description.

As I understand it the inspectors only track and find, the actual destruction is carried out by a different team.

But you're spot on with regards the extent to which the inspectors must be seriously stretched. I speculated earlier in this thread about possible disease spread in future years as a result.

 

[Karol]

Recall reading that some of the nests are inaccessible.

Hmmm. A drone with pesticide spray should be able to dispense with cliff face nests and there is always fipronil custard as a last resort.