Wasps

[PBee]

.......It would help if the 'basis' of your challenges was accurate in the first place. If you have a genuine interest then ask the questions and I will be happy to share what I 'understand' about wasps. If you elect a more adversorial approach don't be surprised if I suggest you go away and do a little more homework to improve the basis of your challenges where I see inaccuracies in them.

The basis of my remarks is the currently accepted science on wasp biology as taken from texts by Spradbury, Archer etc. If these cannot be accepted as a basis for debate then it ends up in unconstructive, diversionary argument over motive etc.. In my opinion, it is unrealistic to suggest that 4-5 metric tonnes of insect prey is foraged to the average wasp nest in the British Isles. It is also incorrect to suggest that high wasp numbers reduce varroa. So we will agree to differ.

 

[Karol]

The basis of my remarks is the currently accepted science on wasp biology as taken from texts by Spradbury, Archer etc. If these cannot be accepted as a basis for debate then it ends up in unconstructive, diversionary argument over motive etc.. In my opinion, it is unrealistic to suggest that 4-5 metric tonnes of insect prey is foraged to the average wasp nest in the British Isles. It is also incorrect to suggest that high wasp numbers reduce varroa. So we will agree to differ.

To disagree is healthy.

Interesting turn of phrase - currently accepted science!

Depends on whether you scrutinise the scientific method behind much of the work that has been done or whether you accept it blindly. My training has always taught me never to trust any source unless it is independently robustly corroborated. The level of corroboration and scientific diligence in the study of wasps leaves a fair bit to be desired. There is some good work but there is also work which whilst it provides an insight, doesn't provide a conclusive picture. There's nothing absolute when it comes to wasps.

It's interesting for example that the authors concede that results might have been skewed because there's no guarantee that all adult wasps were captured during sampling. So, in how many of the studies did they specifically define in the method that sampling was carried out in the middle of the night to ensure all wasps were resident within the nest and the measures taken to prevent escape? And, once a nest is sampled the destructive process interrupts further study so how is the population of the nest referenced to the developmental stage of the nest when each year the staging is different based on weather patterns. Moreover, what's an average nest? In 2011 I think it was, there was a wasp nest found in Southampton which was almost 3m in diameter! In Oz, the largest nest was 7m in diameter with millions of wasps in the colony. Go figure!

As for the NZ papers, why initiate sampling on foraging rates when the wasps were in the sweet feeding phase of their life cycle? Mid-January in NZ is equivalent to mid-July in the UK, i.e. after the bulk of the brood had been raised and hatched into adults! Sampling should have started at the beginning of October if not earlier. It's no wonder at all that the results only delivered a few kilos!

It's not surprising that overwintered nests send out sweet foragers that go after honeydew. What's surprising is that these nests have any further brood at all although that's not especially clear from the methodology either because presence of brood is used to define an overwintering colony and the presence of brood is not confirmed beyond that point (from recollection). So IMHO the picture is confused in NZ because there are 2nd year colonies that provide sweet feeding wasps at the same time that 1st year colonies have hunting wasps going after insect prey for larval development.

As for your challenge regarding 4 to 5 metric tonnes of protein to raise approximately 1 Kg of wasps, then this is plainly silly as the bulk of an insect is not protein. The exoskeleton of insects is made from chitin which is a complex sugar. So the bulk (IMHO) of the 4-5 metric tonnes of insects is carbohydrate used to 'fuel' the activities of the nest during larval development.

As for motive well you questionned mine before you even started asking technical questions which kinda set the scene. Bit of a shame really.

Why is it incorrect to suggest that high wasp numbers reduce varroa?http://www.beekeepingforum.co.uk/showthread.php?t=26258&page=3

 

[Chris Luck]

Why is it incorrect to suggest that high wasp numbers reduce varroa?

I think you have missed the point. The earwigs in the thread you linked to are postulated to have eaten the dead or perhaps nearly dead mites that fell from the OM hive base.

There can be no suggestion that wasps enter honey bee colonies and eat mites....

.....although I suppose by some peoples thinking if wasps hasten the demise of a honey bee colony that sort of reduces the varroa.

Chris

 

[Karol]

I think you have missed the point. The earwigs in the thread you linked to are postulated to have eaten the dead or perhaps nearly dead mites that fell from the OM hive base.

There can be no suggestion that wasps enter honey bee colonies and eat mites....

.....although I suppose by some peoples thinking if wasps hasten the demise of a honey bee colony that sort of reduces the varroa.

Chris

I think you've provided your own answer. I have always maintained that wasps improve bee fitness by weeding out diseased and weakened colonies and they provide a form of 'quarantining' by limiting the further spread of disease.

In the case of varroa then they will take 'dropped' varroa. In the case of colonies that have collapsed as a consequence of varroa then wasps will take the varroa as well thereby reducing risk to robbing bees picking up the mites.

 

[Chris Luck]

I think you've provided your own answer. I have always maintained that wasps improve bee fitness by weeding out diseased and weakened colonies and they provide a form of 'quarantining' by limiting the further spread of disease.

In the case of varroa then they will take 'dropped' varroa. In the case of colonies that have collapsed as a consequence of varroa then wasps will take the varroa as well thereby reducing risk to robbing bees picking up the mites.

As I thought we need to stop killing wasps, must be why my bees are so healthy because all the wasps and hornets are too busy eating all those mites from my untreated hives.

Chris

 

[Karol]

As I thought we need to stop killing wasps, must be why my bees are so healthy because all the wasps and hornets are too busy eating all those mites from my untreated hives.

Chris

We do certainly need to stop killing wasps indiscriminately. In my opinion they need to be managed for the benefit that they bring. Healthier wasp populations significantly decrease the need for garden pesticides which improves the environment for bees and other pollinators. In my book, there is a much bigger environmental picture here that doesn't get enough attention.

 

[Putnamsmif]

We do certainly need to stop killing wasps indiscriminately. In my opinion they need to be managed for the benefit that they bring. Healthier wasp populations significantly decrease the need for garden pesticides which improves the environment for bees and other pollinators. In my book, there is a much bigger environmental picture here that doesn't get enough attention.

The current watchword is, I believe, biodiversity. A natural balance is what's needed, however our countryside is not by any stretch of the imagination in a natural balance, and never will be again. The destruction of a few individual nests for the benefit of our bees is never going to have a massive impact on the overall wasp numbers, but a hundred yards away there's almost certainly going to be another nest so is it going to have a beneficial affect on the bees anyway?

 

[Karol]

The current watchword is, I believe, biodiversity. A natural balance is what's needed, however our countryside is not by any stretch of the imagination in a natural balance, and never will be again. The destruction of a few individual nests for the benefit of our bees is never going to have a massive impact on the overall wasp numbers, but a hundred yards away there's almost certainly going to be another nest so is it going to have a beneficial affect on the bees anyway?

Well there's a question. Personally I don't like the destruction of wasp nests unless they are a clear and direct threat. Experience shows that destruction of the odd nest doesn't really have much impact on overall nuisance wasp levels for the reason you suggest.

What's also interesting is that if the nest is destroyed at the wrong time in the wrong way then there is the potential to actually create more nuisance wasps than if the nest were left alone. Nest destruction can in certain situations therefore 'precipitate' or increase the level of wasp attack on hives.

Nothing is quite what it seems with wasps!

 

[mbc]

Nothing is quite what it seems with wasps!

Apart from the fact that they are little beasties who respond to stimuli same as all other beasties, they can be trapped in very simple and inexpensive traps and once they are dead they're not a nuisance.

 

[jenkinsbrynmair]

Nothing is quite what it seems with wasps!

Was out fishing Sunday in balsam land and many a wasp I saw plastered in Balsam pollen - maybe someone is re-training them after hearing all the hand wringing this year about the demise of the honeybee?
Pure Cothi valley wasp honey? - doesn't have the same ring somhow. Maybe pure raw cold filtered and bottled Cothi valley wasp honey sounds better

 

[Karol]

Apart from the fact that they are little beasties who respond to stimuli same as all other beasties,

True but understanding what those stimuli are and how they respond to them is key.

they can be trapped in very simple and inexpensive traps and once they are dead they're not a nuisance.

I have to abide by forum rules so can't comment.

 

[Karol]

Was out fishing Sunday in balsam land and many a wasp I saw plastered in Balsam pollen - maybe someone is re-training them after hearing all the hand wringing this year about the demise of the honeybee?
Pure Cothi valley wasp honey? - doesn't have the same ring somhow. Maybe pure raw cold filtered and bottled Cothi valley wasp honey sounds better

Wasps are quite prolific pollinators during the sweet feeding periods. They do lay down honey but it's crystalline in nature and in such microscopic quantities that no one knows why they do it. My pet theory is that it's sugars that have crystallized in the crop that wasps can't digest and are then forced to regurgitate. Anhydrous glucose is very difficult to dissolve especially in concentrated sugar solutions.

 

[AdrianSmith]

The basis of my remarks is the currently accepted science on wasp biology as taken from texts by Spradbury, Archer etc. If these cannot be accepted as a basis for debate then it ends up in unconstructive, diversionary argument over motive etc.. In my opinion, it is unrealistic to suggest that 4-5 metric tonnes of insect prey is foraged to the average wasp nest in the British Isles. It is also incorrect to suggest that high wasp numbers reduce varroa. So we will agree to differ.

I've almost certainly missed something in my speed-reading attempt at catching up, so forgive me if this has already been covered. One of the references to one of the papers was:
Lozada M, D’Adamo P. 2006. How long do Vespula germanica wasps search for a food source that is no longer available? Journal of Insect Behavior 19 (5): 591-600.
Have you seen it? I could only find versions I had to pay for, and I'm not that interested.

It occurred to me that feeding animals leads to unrealistic observations (foxes and chicken coups springs to mind), and that 4-5 metric tonne figure might be skewed by such effects. Nature tends to keep things hungry and a summary of the above paper might give you an idea of how to unskew the figures.

 

[Karol]

I've almost certainly missed something in my speed-reading attempt at catching up, so forgive me if this has already been covered. One of the references to one of the papers was:
Lozada M, D’Adamo P. 2006. How long do Vespula germanica wasps search for a food source that is no longer available? Journal of Insect Behavior 19 (5): 591-600.
Have you seen it? I could only find versions I had to pay for, and I'm not that interested.

It occurred to me that feeding animals leads to unrealistic observations (foxes and chicken coups springs to mind), and that 4-5 metric tonne figure might be skewed by such effects. Nature tends to keep things hungry and a summary of the above paper might give you an idea of how to unskew the figures.

Thanks Adrian. I have seen the paper. Don't really have much to add save that in my experience it also depends on the nature of the food source and the foraging technique being used. So for example, hunting wasps behave very differently to scavenging wasps and pin point swarm feeding wasps behave differently to terrain feeding wasps, etc, etc.

Any scientific work which results in an interaction will skew results. The figure of 4-5 metric tonnes itself is not so important - angels and pin heads etc. What is important is that the figure is 'large' and has a significant ecological impact. What is also important is that wasps need to be valued and that control of wasps needs to be judicious and sustainable.

 

[mbc]

Any scientific work which results in an interaction will skew results. The figure of 4-5 metric tonnes itself is not so important - angels and pin heads etc. What is important is that the figure is 'large' and has a significant ecological impact. What is also important is that wasps need to be valued and that control of wasps needs to be judicious and sustainable.

All of this I can readily agree with.
Well put too.

 

[PBee]

Moreover, what's an average nest? ..... Go figure!

You have answered this ....

Did you know that an average wasp nest, a little bigger than a large football, will eradicate between 4 to 5 metric tons of insects in one year. That’s enough insects to fill a 5000 sq ft warehouse and there are about 1,000 wasp nests per square mile!

To put it into context, the larval brood maximum in an average nest of wasps in the UK would cover half a national brood frame.

As for the NZ papers, why initiate sampling on foraging rates when the wasps were in the sweet feeding phase of their life cycle? Mid-January in NZ is equivalent to mid-July in the UK, i.e. after the bulk of the brood had been raised and hatched into adults! Sampling should have started at the beginning of October if not earlier. It's no wonder at all that the results only delivered a few kilos!

You are mangling wasp biology beyond all recognition. Based on Archer 2008 Taxonomy and nesting biology ….. In both England in mid-July and New Zealand in January, vulgaris colonies are in small cell colony phase and are still developing. The maximum number of workers occurs in the large cell colony phase which begins in early August in England and in March in NZ......

In New Zealand, colonies are initiated from mid-September until late November with peak initiations in early October. Probably the first workers emerge from mid-October. Large-cell building is started during March with the first queens emerging from early April and colony termination from late May until early June. Colony cycle is about eight months (240 days)…….
P. vulgaris. In England, colony initiation is from mid-May, the first workers emerging from early June, large-cell building from early August, the first queens emerging from mid-September or earlier and colony termination by the end of October. Colony cycle is about 5.5 months (170 days).

Honeydew foraging is equally high in January (SCC), March (Early LCC) and May(Late LCC) in NZ so occurs when the colony is actively rearing brood and close to termination of the colony.

Honeydew drops produced by beech scale insects (Ultracoelostoma assimile) on beech trees (Nothofagus) in a relict beech forest within a pine plantation near Nelson, New Zealand, were measured on 3 areas of trunk: an unprotected control area, an area screened to allow insects but not birds to feed on the honeydew, and an area screened to exclude all insects and birds. The experiment showed honey-eating birds (tui (Prosthemadura novaeseelandiae), bellbirds (Anthornis melanura) and silvereyes (Zosterops lateralis)) had little effect on the honeydew, but that cropping by German wasps (Vespula germanica), and particularly by common wasps (V. vulgaris), in the summer and autumn months markedly reduced the number, size, and sugar concentration of the honeydew drops. The energy in drops per unit area of tree trunk was reduced by at least 99.1%, 98.4% and 91.3% in January, March, and May, respectively. http://www.cabdirect.org/abstracts/19920506505.html;jsessionid=071EB289856225B860189F59595BFF66

 

[Karol]

You have answered this ....


To put it into context, the larval brood maximum in an average nest of wasps in the UK would cover half a national brood frame.

You need very little change in the dimensions of a wasp nest to go from 2000 to 5000 workers but it will make a significant difference to the amount of insects foraged throughout a season. So, for example, a nest with a radius of 12cm has a volume of approximately 7 litres. A nest with a radius of 15cm has a volume of approximately 14 litres. Most people would find it hard to differentiate between the two visually without them being side by side.

We will have to agree to disagree. I am happy to defend my position that I believe that 4-5 metric tonnes is a realistic figure but as I've said, the figure itself isn't that important. What is important is that the figure is large and has a significant ecological impact.

You are mangling wasp biology beyond all recognition. Based on Archer 2008 Taxonomy and nesting biology ….. In both England in mid-July and New Zealand in January, vulgaris colonies are in small cell colony phase and are still developing. The maximum number of workers occurs in the large cell colony phase which begins in early August in England and in March in NZ......
Honeydew foraging is equally high in January (SCC), March (Early LCC) and May(Late LCC) in NZ so occurs when the colony is actively rearing brood and close to termination of the colony.

I've already said that I don't feel confident about comparing wasp behaviour between the two countries because environmental conditions are so different and environmental conditions have an impact on the biology of wasps. Winter temperatures in NZ range from 10° to 15°C and food remains abundant throughout both of which favour 2 year colony survival (germanica). This clearly will have an impact on the extent of sweet feeding that is seen at different periods in the year.

As for sampling being done from mid January onwards, it still misses out the bulk of the hunting season and therefore casts doubt on the figures presented in the NZ papers. And I have yet to meet the clockwork variant of either species where they stick to a defined time table. Without relating where the nest is in its development the results are largely meaningless. The only way in which one can tell where the nest is in terms of staging is by destroying it. Hardly optimal!

And are you sure that you are not miss interpreting what has been written? The maximum number of workers does occur in the LCC because they are largely the product of the SCC stage. LCC is ostensibly about the production of sexual progeny.

I don't have any more to add. Continuing this debate I suspect will be perceived as bickering by the forum. So unless you bring something new to this discussion I shall politely refrain from further discourse.

 

[mbc]

We will have to agree to disagree. I am happy to defend my position that I believe that 4-5 metric tonnes is a realistic figure but as I've said, the figure itself isn't that important. What is important is that the figure is large and has a significant ecological impact.
After contemplating this figure and doing a few sketched sums, I reckon less than 2 tonnes would be more realistic for the average nest, and thats weight at the kill rather than the weight of material rthe foraging wasps actually deliver to the nest.


. Winter temperatures in NZ range from 10° to 15°C

?! This sort of statement is so nonsensical that it knocks my confidence in everything else you post.

 

[Karol]

?! This sort of statement is so nonsensical that it knocks my confidence in everything else you post.

Which statement is that?

Temperature viz;

http://www.tourism.net.nz/new-zealand/about-new-zealand/weather-and-climate.html

Or arguing the toss between 4-5 metric tonnes and 2 metric tonnes which in either case are both still 'large' quantities and still have an ecological impact! These figures are based on assumptions and it only takes the wasp season to be one month late to skew the results dramatically. Wasp nests mature at different times from one year to the next. The latest we've seen them mature is early November. The earliest we've seen them mature is the third week in July. The earliest we've seen nest building start is March. We've seen nest building start as late as June. As for weight at kill vs weight brought back to the nest then this again is one of those 'so what' distinctions. At the end of the day the insect is dead, i.e. eradicated! Not to be pedantic but I never made any claims that wasps will 'carry' back 4-5 metric tonnes of insects back to the nest.

Notwithstanding all of the above I'll quite happily accept both figures because at the colony level it only takes a small incremental difference to have a dramatic impact on the total amount that is foraged. Makes no odds to me and arguing the toss won't change the way in which wasps behave or the impact that wasps have on their surroundings.

 

[mbc]

Which statement is that?

Temperature viz;

http://www.tourism.net.nz/new-zealand/about-new-zealand/weather-and-climate.html
.

"average maximum temperature ranges between 20 - 30ºC and in winter between 10 - 15ºC."
is dramatically different to;
"Winter temperatures in NZ range from 10° to 15°C".
If you cannot see that then you are quite right, theres no point arguing the toss.
Parts of the South Island are popular with Kiwi's for skying and even in the far North of the North Island its not unheard of to have sharp frosts.

Again, with the 4 to 5 tonnes of foraged insects, do you not think even a modicum of accuracy is necessary for an informed discussion ?
You may feel this is realistic and worth rebroadcasting as if its fact, but anybody with a pencil and a bit of paper coupled with a few real facts about seasons and daylight hours, individual wasp payloads and average wasp nest populations can quickly calculate that it would only be close to possible if the wasps did little else, truth is they spend as much time housekeeping or just hanging out at the nest as bees do, so the figure is way over the top, possibly by an order of magnitude or two.