Asian Hornet heads up for the Scots

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I have no wish to get drawn back into the forum but I think this issue deserves comment because of the potential for wider environmental impact.

IMHO the advice to set traps in spring is plain wrong, naïve, ecologically destructive and absolutely counter productive.

In the fight against Velutina, the best friends that honey bees and bee keepers have are native species of wasp. Why?

Quite simply because wasps compete with Velutina. Remove wasp populations by killing queens in traps set in spring and you create the space which Velutina needs to establish itself. If you have healthy wasp populations they will suppress insect populations that would otherwise support Velutina and they will also compete aggressively and fight with Velutina.

I suspect that the UK has had hundreds of Velutina queens imported silently over the past decade in goods from France and elsewhere but they have failed to establish themselves. The last thing that beekeepers should be doing is creating optimum conditions for Velutina to establish itself by removing the native competition.

Moreover, native wasps around the hive are comparatively easy to deal with if you have the right knowledge. Just ask Millet! Velutina is much harder to control around hives so every little bit helps and that includes maintaining a healthy wasp population.

The best thing to do is simply monitor your hives for signs of hawking Velutina. If and when you see Velutina, that'll be the time to act. Don't be sucked into the maelstrom of paranoia circulated in the media and don't set spring traps on the off chance.

:iagree::iagree: .. I will listen and only listen to you as far as wasps and Hornets are concerned, after my problems a while back you stepped in and offered advice and give me a solution to the problem and lone behold my hive was safe from wasps within minuets of doing what you advised, before you helped i would kill every wasp and queen wasp i seen, now i do not need to as they are of no threat to my hive / hives, simply through one bit of DIY, i have a wasp trap but that is in the shed where it will stay till next year and the year after and so on unless the wasps in late Autumn become a nuisance , however if hornets do turn up and attract to my Apiary they will get the full shebang..:D
 
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Really!
<snip> That means in an average nest each wasp larvae, weighing around 0.1g, eats its way through approx 500g of dead insects, 5000x their own weight in 12-18 days.
<snip?

27000 times their body weight makes wasp larvae look like they're attending weight watchers by comparison!

https://www.thenakedscientists.com/articles/interviews/captivating-caterpillars

That's not for your benefit Beefriendly. That's for the benefit of those reading this thread that might fall for your nonsense and be tempted to set spring traps as a result.

I've done my bit. I'll leave the rest to those responsible bee keepers on this forum to spread the advice to monitor hives but not to trap without confirmation.
 
Explain how they get the elephants worth of larvae into the nest in a month, that's works out at at over 50lbs of dead insects per day per nest and all during daylight hours..... Where does all the excrement go?
Mr Pazic, you need to provide the reference for your wasp claim. A scientific one if it's possible.
 
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A lecture told us that a large wasp colony can shift 2000lbs a month in dead protein.
Is this wrong ?
Explained why they became a problem late season as no brood secreting sugar for the wasps adults.


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A lecture told us that a large wasp colony can shift 2000lbs a month in dead protein.
Is this wrong ?
The logistics of them actually doing this (as I have outlined) suggest it may well be wrong. Perhaps it refers to the total biomass predated per square mile by 1000 nests and a simple mistake in translation has been made by someone at some stage that has then been repeated and propagated by others. Something similar to the "fact" that edible honey was found in the Pharaohs tombs.
 
No idea mate it was at a lecture about them.
I only know they are a pain in the arse come late summer.


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The average vulgaris or Germanic nest requires circa 4 to 5 metric tonnes of insects to mature. There are maximally 1000 nests per square mile depending on topography.

The average honeybee colony is roughly the same size and scientists I trust (Seeley, Winston) report a range of estimates of the amount of pollen they would consume annually at 15-55 kg. Ish. Given that wasps will use some of their protein crop to turn into energy for the colony rather than gather all their requirement as nectar maybe we should double those estimates so let's take a middle part of the honey bee range and double it to say roughly 40-80 kg insects gathered per German wasp colony.

4,500/60 = 75 Karol is maybe 75 fold out. Not 5 elephants but just part of a trunk perhaps.

Ref: Cane and Tepedino (2016) http://onlinelibrary.wiley.com/doi/10.1111/conl.12263/pdf
 
The average honeybee colony is roughly the same size and scientists I trust (Seeley, Winston) report a range of estimates of the amount of pollen they would consume annually at 15-55 kg.

Better to have it measured scientifically rather than guestimated.
The amount of insects in weight consumed by an average wasp nest is between 1-15kgs maximum (see below).
Karol states 4-5000 kg of insects per nest, which is ludicrous.

The weight in term of insects caught and brought back to the nest (and also honey dew collected) by both V. germanica and V. vulgaris has been determined in New Zealand where the nest sizes are pretty equivalent with those in the UK.
The actual figures show 0.8 and 4.8 million prey loads per hectare per season entered nests in western and northern South Island honeydew beech forests, respectively. This represents a biomass of 1.4 and 8.1 kg/ha collected. They actually trapped wasps and determined exactly what each was carrying, insect, honey dew or in the majority of cases nothing.
Now wasp nest densities vary but they determine that each nest will consume between 1kg to 15kgs of prey, depending on nest size, over a years cycle.
Now 15kgs per nest lets call it 10 as an average maximum insects consumed over a nest cycle is a long long way from the claimed 4-5 metric tonnes(4-5000kg) per nest: about 400x to 500x less, a considerable discrepancy and one that needed correcting.

source- Diet of the wasps Vespula vulgaris and V.germanica in honeydew beech forest of the South Island, New Zealand by Richard Harris
 
Look what I found yesterday, I think you are better off looking in empty hives, sheds etc instead of indiscriminately trapping.
 

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Look what I found yesterday, I think you are better off looking in empty hives, sheds etc instead of indiscriminately trapping.

Thank goodness you are in Portugal....for a minute you had me going!
 
The average honeybee colony is roughly the same size and scientists I trust (Seeley, Winston) report a range of estimates of the amount of pollen they would consume annually at 15-55 kg. Ish. Given that wasps will use some of their protein crop to turn into energy for the colony rather than gather all their requirement as nectar maybe we should double those estimates so let's take a middle part of the honey bee range and double it to say roughly 40-80 kg insects gathered per German wasp colony.

4,500/60 = 75 Karol is maybe 75 fold out. Not 5 elephants but just part of a trunk perhaps.

Ref: Cane and Tepedino (2016) http://onlinelibrary.wiley.com/doi/10.1111/conl.12263/pdf

I expect the true figure will be somewhere in between.
Bear in mind that a large part of the weight in insects wasps bring back to the nest is water.
 
I expect the true figure will be somewhere in between.
Bear in mind that a large part of the weight in insects wasps bring back to the nest is water.

No, the actual observed and measured figure is a maximum of 15kg's of insects per nest. If that is mainly water then the true protein value will be even less. The researchers calculated the weights and amounts of liquid honeydew and nectar brought back separately. But we are debating insect brood food, not wasp food.
 
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I have spoken with one of the SBIs who was sent to Tetbury last year. My recollection is that they found almost no Asian Hornets in apiaries - most were at a forage site where ivy was in flower. The AHs were foraging on anything that came to the ivy - honeybees, wasps, flies, butterflies so spring monitoring using "catch and release" traps does not necessarily have to be done in an apiary - it's probably better to do it where there's good forage for bees etc. where it's convenient to monitor the trap - I have one of the NBU-designed monitoring traps in my garden outside my backdoor where I can check it regularly.

Down here in Cornwall there has been a big education push over the winter so that all beekeepers can identify the Asian Hornet. I've been to 3 events where an SBI has had a session educating beekeepers about the potential pest.

I myself obtained a supply of dead Asian Hornets of Plenty of Honey (Brittany) and put each one in a small see-through plastic container and distributed them via the CBKA around Cornwall. I'm going the a meeting on Monday where I will lead a discussion among local beeks about the Asian Hornet. The main theme will be Recognise the Beast! I will also display the latest NBU design of monitoring trap.

What are the chances of a AH turning up in my monitoring trap? - practically zero but I'd be pretty disappointed if an AH nest was found down the road from me and I had done nothing.

CVB
 
I have been prompted by several private e-mails to respond to the findings in the paper written by Harris (Diet of the wasps Vespula vulgaris and V.germanica in honeydew beech forest of the South Island, New Zealand) as cited by Beefriendly. Sadly the forum archives where I previously addressed the paper by Harris a few years ago on this very same subject no longer appear to be available as the archives only extend back to 2015/2014.

There are two critical factors which undermine the relevance of the findings of Harris compared to the UK.

The first and most important is that the work conducted by Harris singularly failed to take into account the different dietary behaviour of wasps depending on where they are in their life cycle and the amount of brood in the nest. Sampling of wasps in the Harris study in both years occurred during the sweet feeding phase, i.e. the equivalent of August through to October in the UK. Typically the hunting phase in the UK comes to an end in July (January in New Zealand) when the queen stops brood production which peaks with the production of sexual castes. It is no surprise therefore in the Harris paper that the prey loads retrieved were miniscule because the nests that were sampled contained little if any brood.

The observation is further corroborated in the Harris paper by the disproportionately high number of foragers returning with nectar filled crops. Moreover, during the sweet feeding phase, foraging behaviour changes dramatically in terms of nest aggregation. During the hunting phase adult wasps are fed regurgitated carbohydrates digested from insect skeletons by the grubs which encourages a significantly higher traffic rate. During the sweet feeding phase, when there is rapidly declining or no brood to feed the adult population, individual wasps spend most of their time away from the nest sweet feeding so the traffic rate falls away drastically and the nests almost appear deserted.

The second major factor which undermines the relevance of the Harris study to the UK is the difference in the availability of honey dew which skews both dietary behaviour (away from hunting) and population densities. The UK simply doesn't have the carbohydrate profile that exists in New Zealand. The Harris paper quotes a wasp biomass in the Nelson region as 5,200 g/ha, i.e. 1,346,800g/sqm. The average weight of a wasp is between 0.07 and 0.1g which calculates through to 13,468,000 wasps per square mile or 2,694 nests (based on an average nest size of 5000 adult wasps). This far exceeds the population dynamics of wasps in the UK and understandably so.

What is interesting though is that the Harris paper quotes the amount of honeydew taken per hectare as between 78 litres and 343 litres, i.e. 78,000g to 343,000g (assuming roughly the weight per ml to be 1) per hectare or 20.2 tonnes to 88.8 tonnes per square mile.

Honeydew contains between 16% (at 9.00am) and 40% (around noon) and up to 70% (on standing) glucose. Insects typically contain between 3 and 6% glucose. Assuming that wasps need to consume the same amount of carbohydrates irrespective of where they are in their life cycle, this extrapolates the tonnage to 202 to 888 tonnes per square mile of glucose equivalent insect mass in free (as opposed to fixed) carbohydrate poor environments.

Nominally the pay load carried by wasps doesn't tend to exceed 30mg. Interestingly wasps manipulate their prey into convenient pay loads by dismembering and dissecting their prey so much of the prey doesn't make it back to the nest. Insect weights vary tremendously from a few mg to tens of grams. The Harris paper quotes wasps feeding on wetas which are large crickets typically between 3 to 6g in weight, i.e. between 100 to 200 times the weight of the average wasp pay load. Just extrapolating by a conservative 10 fold gives 2020 to 8880 tonnes per square mile of insects required to sustain wasps (which should not be confused with the pay load weight).

Taking into account the 2694 nests this gives a figure of circa 3.3 tonnes per nest and these inferences drawn from the Harris paper put the tonnage into the right ball park.

Incidentally, the figure of 4 to 5 metric tonnes is one that I read in a reference book which at the time I thought was a 1000 fold mistake. (For the life of me I can't dig out the reference but it's not too dissimilar to what Nige.Coll posted) and I spent quite a bit of time trying to disprove it but finally came to the conclusion that it is a realistic figure.

Anyway, perhaps the most interesting conclusion from the Harris paper is that wasps represent the most important predatory group preying on insect pests and we eradicate them injudiciously at our peril.

Please please don't set spring traps for Velutina unless its presence has been confirmed. Doing so will IMHO only serve to open the door to allow it to become established.
 
If you have healthy wasp populations they will suppress insect populations that would otherwise support Velutina and they will also compete aggressively and fight with Velutina.

The wasps will suppress many of the smaller insect populations... but the wasps themselves would also provide a good food source for the Asian hornets, and a favorite food of the European Hornet.
 
Critique of scientific papers advice for beginners....

Sampling of wasps in the Harris study in both years occurred during the sweet feeding phase, i.e. the equivalent of August through to October in the UK. Typically the hunting phase in the UK comes to an end in July (January in New Zealand) ].
Point no.1, Get your facts right.
Summer (i.e the time of wasp number expansion. the hunting phase) in New Zealand is usually defined as the period from January through to the end of March early April. Google it if you think I've got the timings wrong. I haven't.
The sampling in the paper was performed at 1 site between 2nd Feb and 7th of May and at another between 18th Feb and 10th April. So the sampling was conducted at a time that wasps were actively foraging for insects. Y

Point no. 2. If you have decided the data is flawed then it is fatal to your argument to use that data in support of your own hypothesis.

Hope that proves of some help to you in the future.

What neither of us have mentioned is the reason this study took place. It was because of the potential detrimental effect that wasps preying on insects may be having on the native insectivorous bird life.
Invertebrate prey are a limiting resource for insectivorous birds in honeydew beech forest, as is thought to be in other habitats (Gibb 1960; Catterall 1985), and is the case for Kaka feeding on honeydew (Beggs & Wilson 1991), one would predict that the carrying capacity of beech honey dew forests for insectivorous birds would be reduced when wasps are present.

One could suggest that in this country wasps will impact on our native insectivorous songbird numbers by competing for similar prey.
Perhaps a reason to trap queens to lower nest density in the spring to allow our native insectivorous bird life to thrive.
 
Point no.1, Get your facts right.
Summer (i.e the time of wasp number expansion. the hunting phase) in New Zealand is usually defined as the period from January through to the end of March early April. Google it if you think I've got the timings wrong. I haven't.
The sampling in the paper was performed at 1 site between 2nd Feb and 7th of May and at another between 18th Feb and 10th April. So the sampling was conducted at a time that wasps were actively foraging for insects. Y

Point no. 2. If you have decided the data is flawed then it is fatal to your argument to use that data in support of your own hypothesis.

Hope that proves of some help to you in the future.

What neither of us have mentioned is the reason this study took place. It was because of the potential detrimental effect that wasps preying on insects may be having on the native insectivorous bird life.
Invertebrate prey are a limiting resource for insectivorous birds in honeydew beech forest, as is thought to be in other habitats (Gibb 1960; Catterall 1985), and is the case for Kaka feeding on honeydew (Beggs & Wilson 1991), one would predict that the carrying capacity of beech honey dew forests for insectivorous birds would be reduced when wasps are present.

One could suggest that in this country wasps will impact on our native insectivorous songbird numbers by competing for similar prey.
Perhaps a reason to trap queens to lower nest density in the spring to allow our native insectivorous bird life to thrive.

Having lived in South Africa ie Southern hemisphere and celebrated Christmas in summer heat, surely in New Zealand the springtime/summer are also 6 months ahead/behind our Norther hemisphere seasons? October, November, December would be their springtime going into summer. January would be their midsummer heading into Autumn when the wasps finish brood rearing and sweet feeding begins if I've understood correctly.
 
January would be their midsummer heading into Autumn when the wasps finish brood rearing and sweet feeding begins if I've understood correctly.
The more relevant question would be more along the lines of why would a scientist investigating the biomass of insects predated by wasp choose a time when they weren't feeding on insects? The timings are fine, but an exact transcribing of events in the UK to New Zealand is probably not.
Look at the wasp life cycle timings in New Zealand.
http://www.landcareresearch.co.nz/s...ates/invasive-invertebrates/wasps/ife-history
In spring, queens emerge from hibernation and make a new nest;
Over summer the nest expansion and the number of workers increases;
In autumn the nest produces males (drones) and females (new queens) which can reproduce;
In winter, new queens fly away from the nest and hibernate and the nest usually dies (sometimes nests can survive winter and thus skip the ‘new nest’ phase).

The question still be answered is how do they get 5 Elephant weights into such a small nest in such a short time.....that is the real implausible.
 
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The question still be answered is how do they get 5 Elephant weights into such a small nest in such a short time.....that is the real implausible.

The only way to explain that - because we KNOW a brood nest and stores cannot be that heavyy is the weight has been consumed and left the hive either as dead insects of excrement.

If true, the entrances - or rather the ground near them - should be covered in many centimeters of dead insects and excrement...
 

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