How smal does a gap have to be to stop asian hornets

[charentejohn]

Hopefully not as daft a question as it sounds.
I have searched everywhere for a minimum size, it just says 5.5mm will exclude them. I believe this will also trap drones inside ?

So, bees can get through 5.5mm ok. Drones can get through ?? ok.
Asian hornets can get through ?? at a push.

Can anyone fill in the blanks ? Sites say how long hornets are but never how wide.
I have some ideas for later when attacks may start that will allow the bees to fly through but slow the hornets. Only problem is that hornets will sometimes 'walk' inside defences. Once on the landing board they can enter the hive, this, in a way, killed my last lot of bees.
Hornets are not happy being trapped inside a mesh barrier but will do it sometimes. They will walk down the hive and through the mesh.

Just fyi. I have tried the 13mm sq mesh and does slow bees down and they can be caught by hornets on the mesh.
So I saw in Spain someone using 25mm chicken wire, bees whizz through, hornets can only just make it so slow down.
Works until a hornet goes inside, bees will chase it from the landing board but it usually has to drop the bee to get out. So they tend to learn to stay outside the mesh. Just trying to guess best guard size to keep them out of the actual hive.

 

[Murox]

Just some ramblings and I am probably totally up the creek hear - but if the incoming hornets have to slow down it gives the edge to the bees. The same could be true for outgoing bees - they reach speed X as they go through the mesh and as the hornet would be hovering it will be slightly slower as it moves to attack the bees. How fast can a bee fly versus hornet ? If the local keepers use 25mm mesh it must work to some extent, also how far from the landing board/hive is the mesh placed ? Can a bee fly flat out through a mesh of say 20mm and what would that do to the hornet?
You will just have to catch a hornet and measure its body width and wing span.

 

[eltalia]

Hornets take bees on the wing yeah..?... least the euro type(wasp)
in Sou'Aussie do. Chicken mesh (~17mm) stops them flying right
in.
Off the top of me head 5.9mm is the number for drones.
Should be g00glable as a Fact check.

Bill

 

[Anduril]

The Nicot hive door anti-Asian hornet is 5.5mm, designed to stop hornets and drones as well, its use needs to be limited. Then you have the shields which look as though they have limited success. When the seasonal bee inspector came to inspect my hives, he commented that my apiary was already set up for the Asian hornet. What you need to do is have an untidy front to the hive, either allow the weeds to grow in front, nettles, grass, goose grass, etc., or stick a maze of bamboo in front, this stops the hornets hawking the hive. One French beekeeper doesn't have a problem with the hornets because he has chickens in the apiary gobbling up all the hornets.

 

[MartinL]

The Nicot hive door anti-Asian hornet is 5.5mm, designed to stop hornets and drones as well,

Anti Asian hornet door", bet the marketing boys were chuffed when they came up with that name?
I may be wrong but, I didn't realise Asian Hornet (velutina) actually entered the hive.

With that in mind, does that make my front door (in the midlands, 400ft above sea level) an Anti tsunami door?

One French beekeeper doesn't have a problem with the hornets because he has chickens in the apiary gobbling up all the hornets.

Don't chickens eat bees too??

The Asian hornet thing is something we'll all eventually have to look into, Maybe Boris can help?

 

[Anduril]

Anti Asian hornet door", bet the marketing boys were chuffed when they came up with that name?
I may be wrong but, I didn't realise Asian Hornet (velutina) actually entered the hive. With that in mind, does that make my front door (in the midlands, 400ft above sea level) an Anti tsunami door?

Don't chickens eat bees too??

The Asian hornet thing is something we'll all eventually have to look into, Maybe Boris can help?

From the map I saw, your front door would be underwater. Can you convert it to a pressurised house, shall we say to 200m.
It's all about the hawking and yes chickens do eat bees.

 

[Murox]

........edit..........
Don't chickens eat bees too??

In my experience the chickens hoover up the dead mainly and occasionally peck one out of any beard on the hive. Hovering hornets and other hovering insects make an easy target if they are within pecking range as they are almost stationary.

 

[MartinL]

From the map I saw, your front door would be underwater.

Not in my lifetime

 

[Anduril]

Not in my lifetime

Never say never!

 

[eltalia]

Anti Asian hornet door", bet the marketing boys were chuffed when they came up with that name?
I may be wrong but, I didn't realise Asian Hornet (velutina) actually entered the hive.

Those that get there get 'cooked' by bees, accordig to Vietanamese anecdotal.

With that in mind, does that make my front door (in the midlands, 400ft above sea level) an Anti tsunami door?

One needs a plate shift to get one going, according to BBC TV it'd take a good part
of Europia to split assunder to get that going, Brexit in spades!

Don't chickens eat bees too??

Not in Texas... apparently Scuttella (sp?) own balls way bigger than beekeepers!

The Asian hornet thing is something we'll all eventually have to look into, Maybe Boris can help?

News here in Aussie today says Boris carn't handle the horny(ette) he's locked
onto, nevermind being concerned with the problems of mere plebes. Heh
/grinz/

Bill

 

[Anduril]

Those that get there get 'cooked' by bees, accordig to Vietanamese anecdotal.

Bill

True with Apis Cerana, Apis Mellifera have not adapted yet.

 

[charentejohn]

Fun posts aside so far a comment that 5.9mm allows drones through, which is good to know as the differences are tiny. So If I made a 6mm or 6.2mm arch all should be able to get in and out but could a hornet squeeze in.
I have searched the net and can't find a thing on the actual minimum size. Traps say drill 9mm holes so I assume we are now somewhere in between.

Hornets do enter hives, killed my bees so I do know this. I had them nearby and an exterminator came and injected white powder insecticide. Loads flew around covered in it. Returning ones found the dying nest and went nuts looking for what did it I guess. I saw two enter the hive, will have been more, and they were in a while but probably had insecticide on them, so the bees died too.
When they get desperate they will go into the hive if the bees won't come out.

Chickens are possibly a help but they can't catch them all. The hornets are smart and learn quickly. Of I approach they fly away, they are not aggressive if the can move away. When I leave they come back.

Lots of anti hornet ideas here, especially spain where they sem to have a real hold.
They hawk but also land and grab bees. The bees can't stop them, I have seen them mob a hornet once that then flew off.
Problem is they hawk near the entrance and pin the bees down, so they are weakened and can starve. Pushing them back from the entrance helps.
Not sure cooking hornets will work if the hornets are arriving en mass as they do later in the year.
I don't think cooking will work with a relentless hornet attack ? Attrition is the key, imagine a line of 10,000 hornets being cooked one at a time by a ball of bees. Who would run out of energy first.
Bees seem to attack if the hornet lands so it works but they can't keep it up forever. The bees that entered my hive, because they were annoyed, just barged straight in and the bees couldn't stop them. Even if they attacked them inside they could have killed the queen (late October).

Not great is the 13mm sq mesh, the bees have to land on it and get caught. Hornets can get inside this but immediately want to get out.
The conclusion is they don't like tight spaces that stop them manouvering. Hence the 25mm mesh.

My plan this time is to use two barriers. First a 10cm sq 'tube' of 25mm chicken wire covering the entrance and landing board. Outside that another tube about 30mm from the inner one. Made to hook onto the hive for easy removal. This should slow the hornets. I have watched them and it is like a penalty shoot out. Bees come in and hornets dive to catch them, they miss and swerve to catch another.
With a guard (called a muzzle here) the bees are not pinned down. If only one or two hornets the bees are ok, dozens and probably not. I need to know what sort of reducer size to use as if a hornet gets to the hive entrance they may panic when unable to manouvre.

I am also thinking of putting a second double layer exclusion zone. This is where I got the idea (can't post link so search for youtube.com/watch?v=fFji7gVzxww
He uses fencing wire (easily formed into a cube) but he covered it in fine mesh. I liked the bird netting though, hornets should hate that, can't land on it and it moves in the wind.
I think just a box of fence mesh in front of the hive will do, hornets come from under the entrance too but that should stop them. Then cover the fence mesh (large openings) with 25mm chicken wire. Add a covering of 25mm anti bird fruit netting spaced outside the chicken wire, also inside hanging like a curtain.

Best you can do is hold them away from the hive. They will dive for the bees but the bees can avoid them. Once it is inside the netting the hornet has to let it go and try another. They will catch a few but they can live with it.

So do we think a 7mm arch would work ?
I just missed out on some replacement black bees and will take them if they come round again.

Long video but 1:30 in he mesures a hornet... (Can't post link) so use youtube.com/watch?v=MBfaKcT0hPg Seems 5mm wide and 30+mm wingspan. Seems to use a massive tent arrangement. Should work as the hornets can't cover it all they need to be 15-20cm from the entrance.

 

[mazzamazda]

They don't go inside the hive until it has failed, I have had them inside mating nucs but generally they do all their hunting outside the hive.

 

[MartinL]

I may be wrong but, I didn't realise Asian Hornet (velutina) actually entered the hive.

OK, maybe twice

They don't go inside the hive

they do all their hunting outside the hive.

3rd time lucky?

Hornets take bees on the wing yeah..?...

They don't go inside the hive until it has failed, .

Can't wait for November

 

[charentejohn]

Could be true on the entering only when the hive is weak, mine wasn't but they were really angry. So they will go in if mad enough.
After this incident they resumed hawking for the rest of the season until winter. Bee numbers reduced but that would be the insecticide. They never recovered.

Not much enters a strong hive but if they weaken it then they just might. I am a, hope for the best but plan for the worst type.

Still no response to the main question as to sizes. Best is the last video where someone measured one at 5mm wide. Allowing for wings and the hornet not wanting to squeeze through I will look at 6.5mm excluders. Better to have it and not need it than need it and not have it.
I have a single Warre hive so they can get by on less and an excluder may make some difference.

 

[eltalia]

"Traps say drill 9mm holes so I assume we are now somewhere in between."
The 9mm number is derived from a theoretical space required for bees
to drag "stuff" out via the cone, inclusive of live bees, the queen in particular.
Having run them at 6mm and as large as 25mm I have found it is more
important to cover the cone up to 60m from the opening, 'forcing' bees
toward the light.
Buuuut another topic for another day... likely in a few weeks time whereon
these swarms now topical will have lodged in some poor buggers eaves
or brickwork.

Bill

 

[mazzamazda]

Could be true on the entering only when the hive is weak, mine wasn't but they were really angry. So they will go in if mad enough.
.

I haven't ever seen an angry asian hornet, of the thousands I have killed only one went for me and I'm sure that was a mistake, disorientated after being pinged by my hive tool. They are very docile, hovering outside makes them really easy targets. I am yet to see a hornet even try and get inside a strong hive so I think any effort in making parts would be better made in killing them.

 

[MartinL]

Why would they want to enter the hive when they can only deal with one at a time?

 

[Millet]

Why would they want to enter the hive when they can only deal with one at a time?

I have watched a video where a group of Asian Hornets entered a hive and destroyed the full colony fairly quickly..it takes them a second to kill a bee and move onto the next one..pretty savage to watch.

 

[For want of a better word]

I have watched a video where a group of Asian Hornets entered a hive and destroyed the full colony fairly quickly..it takes them a second to kill a bee and move onto the next one..pretty savage to watch.

Like your Terriers on rats!