Ideal wasp trap or vespid torture?

[Wilco]

Had a number of wasps last evening hawking near two of my nucs so I took my fly electrocuter outside to deal with them. I could practice my backhand if nothing else.
Interestingly as soon as I switched it on, they shot off over the garage roof. Disturbed by the mild electrical charge maybe?

Found wasps had worked out a hole in a storage box of supers yesterday. Shook most out and closed the holes with duct tape... Was then surrounded by a cloud of hundreds of docile and sad wasps. I felt rather sorry for them TBH.

 

[Gilberdyke John]

Who said anything about wet comb? Supers with comb are not empty supers are they!

Your own post spoke about empty supers being left open for waps to pick clean. Viz. "
Karol said:
I would suggest leaving the supers open to the elements. That way the wasps will pick the supers clean for you."
By inference an empty super is the result of putting the frames in a full super through the extraction process followed by returning the emptied "wet" frames of comb to the super hence the assembly is now empty of honey.
Do you think there's any point in taking the wet frames out of the super box and leaving just the box out for wasps while trying to find some way of keeping the frames safe somewhere?

 

[Beesnaturally]

Just as quickly as they arrived my wasps have now departed. I think it must have taken a week or to reduce the nests' ability to raise new brood, then another week or so for large numbers of hatching brood to emerge; and now the nests have been depleted. So my report is: high-powered trapping works, depite the fact that you may be feeding them with inefficient traps. Taking down manpower is enough.

Re the wasp/comb-cleaning: I've tried ant cleaning. They'll clean up both wet and dry comb beautifully, but they take a long time to do it. These are 'field' ants - the sort that make big bumps on the ground with nests that apparently go up to 2 feet deep, and there are plenty of them, so I'm surprised they don't get on with the job a little faster. I'm tempted to see what the giant wood-ant nests nearby can do.

 

[Pembroke]

Had a number of wasps last evening hawking near two of my nucs so I took my fly electrocuter outside to deal with them. I could practice my backhand if nothing else.
Interestingly as soon as I switched it on, they shot off over the garage roof. Disturbed by the mild electrical charge maybe?

They'd probably seen your backhand before and knew to avoid it (either that or it was the wasp buzzing equivalent of peeing themselves laughing at your backhand) take your pick

 

[Karol]

Your own post spoke about empty supers being left open for waps to pick clean. Viz. "
Karol said:
I would suggest leaving the supers open to the elements. That way the wasps will pick the supers clean for you."
By inference an empty super is the result of putting the frames in a full super through the extraction process followed by returning the emptied "wet" frames of comb to the super hence the assembly is now empty of honey.
Do you think there's any point in taking the wet frames out of the super box and leaving just the box out for wasps while trying to find some way of keeping the frames safe somewhere?

Depends on what the particular beekeeper's practice is. Not all frames are returned with honeycomb. So for example, in my field, beekeepers manufacture/render pharmaceutical grade beeswax (British Pharmacopoeia that is) exclusively from honeycomb as broodcomb carries too many contaminants and potential pathogens and so frames are stripped of honeycomb in the process leaving them 'empty'. Other beekeepers will sell honey on the comb so similar story. Empty supers for me are just that - empty. The frames within the supers will still have sufficient traces and aroma of honey to attract wasps. If you read the whole of my post you'll also note my comment about washing the supers with a soda solution - hardly appropriate I would suggest for supers full of wet comb!

 

[Karol]

As usual, talking rubbish about something he knows nothing about
We all remember 'the average wasp nest consumes a ton of garden pests in a season' when Professor Serian Sumner (a real wasp expert) heard that, she just rolled her eyes and burst out laughing.

I was going to let this rest not wanting to deny you the obvious pleasure you get from belittling other contributors on the forum but on reflection I think that folk might find the background to this a fascinating doff of the cap to the amazing industry of hymenopterans. So, not for your benefit JBM, but for the interest of others:

When I first embarked on my journey studying and researching wasps and their behaviour back in 2002 I came across an old reference which stated that an average wasp nest would eradicate between 4 and 5 metric tonnes of insect prey. Much as JBM (and Serian Sumner by all accounts) disbelieve this today, so I disbelieved the quote when I first encountered it assuming that it was a typo and should have read 4 to 5 kilos instead. So I set about trying to verify that the author actually meant 4 to 5 kilos only to discover that 4 to 5 kilos of fresh weight of insect prey came nowhere close to satisfying the nutritional requirements of wasps. My bad, and something that I continue to pay for, is that I lost the original reference when my computer was corrupted by malware and so I accept that I deserve all of the ridicule JBM et al dish out to me, not because of the subject matter but because I was sloppy and know better not to fail to secure references which I subsequently go on to quote.

Anyway, enough of setting the scene. Here's the interesting bit:

Nowhere in the circa 800 scientific papers on wasps that I have digested could I find the daily calorific consumption of wasps. However, I was able to find references to the daily calorific consumption of honeybees and for the purposes of today, I'll cite this reference:

https://weblessons.us/docs/farmdocs/apiary/Honey-Bee-Nutrition-by-Zachary-Huang.pdf
The reference states that a worker honeybee requires about 11mg of dry sugar per day. Honeybees are not that dissimilar to wasps in terms of average body mass, i.e. 114mg body mass for the honeybee vs 84mg body mass for Vespula vulgaris (Common wasp).

Rearing Honey Bees, Apis mellifera, in vitro 1: Effects of Sugar Concentrations on Survival and Development (Honeybee control body mass circa 114mg)

Does size matter? – Thermoregulation of ‘heavyweight’ and ‘lightweight’ wasps (Vespa crabro and Vespula sp.) (Common wasp body mass circa 84mg)

It would not be unreasonable to estimate the calorific requirement of wasps as a proportion of dry sugar by average body mass of the two insects, i.e. 11mg x 84/114 = 8.1mg dry sugar per day per wasp. Wasps are naturally busy insects spending quite a bit of time flying but it could be argued that honeybees work harder so reducing this figure to 0.8mg of dry sugar per day per wasp (i.e. 1/10th the activity of a worker honeybee) would be more than a cautious estimate.

The typical nest size for Vespula vulgaris is circa 5000 wasps meaning that the daily calorific requirement for the nest would be of the order of 0.8mg x 5000 = 4g of dry sugar per day. That really doesn't sound like much but here's the thing.

During the hunting phase which may last from May to October, adult wasps in the nest will be ostensibly fed by the process of trophallaxis. The larvae in the nest are fed by the adults with insect prey rich in fats, proteins and some sugars (predominantly chitin). The wasp larvae digest that insect prey and then regurgitate the sugars as trophallactic liquid to feed the adult wasps in return. The following reference clearly demonstrates that larval saliva predominantly contains carbohydrates as a source of calorific energy.

Similarity of Amino Acids in Nectar and Larval Saliva: The Nutritional Basis for Trophallaxis in Social Wasps on JSTOR (circa 9% carbohydrate content for Vespula vulgaris)

We know that during the hunting phase the carbohydrates used to power the wasp nest principally come from digested insect prey. (Note this applies to the UK and not antipodean territories).

The question that needs to be answered is how much carbohydrate is there in the average insect which is where this reference is useful:

https://www.researchgate.net/publication/305396814_Nutritional_and_sensory_quality_of_edible_insects
The reference cites the figure of 49.8mg of carbohydrate per Kg of fresh weight of insects as the upper figure. Using this upper figure provides for a cautious estimate of the fresh weight of insects required to power a wasp nest on a daily basis, i.e. 4g/49.8mg or 4g/0.0498g = 80Kg!

80Kg per day over the space of 6 weeks works out to be 3.6 metric tonnes of fresh weight of insects.

Fresh weight is effectively the weight of insects eradicated by wasps and should not be confused with payload weights which are frequently quoted in some scientific papers.

Taking the argument the other way, i.e. starting from a figure of 8Kg per annum per nest taken from this reference:

https://www.itv.com/news/2016-06-10/experts-create-a-buzz-as-they-reveal-why-we-should-love-wasps
8Kg of fresh weight of insect prey will provide 49.8mg x 8 = 398.4mg or 0.398g of carbohydrate.

That's 8Kg of insects for the whole season for a nest. Taking a season to be 6 weeks this is equivalent to 0.398g/42 = 0.009g of carbohydrate per day per nest or
0.009g/5000 = 0.0000018g or 0.0018mg per wasp per day.

Given that a honeybee consumes about 11mg of dry sugar a day I find it hard to believe that a wasp gets by with 0.0018/11 = 1/6000th of the calorific requirement of a honeybee.

As I have repeated many times, my bad for losing the original reference but no matter what method I use to verify the original quote, be that calorific or physical payloads and activity, I keep getting answers of similar magnitude to the original quote.

I guess it's time for the predictable fun to start.

 

[jenkinsbrynmair]

my bad for losing the original reference

very convenient that. You would think if it were true it would be common knowledge.
And as I said, Dr Sumner has done extensive research on this, checked credible data (what little there is) and has found no evidence of this magical ton of insects a year per wasp colony.
so, do I believe someone who did her PhD studying wasps and is now a world renowned expert, or some hack who professes to be an expert but really just wants to sell a load of very expensive wasp traps to the unknowing public?

 

[Karol]

Who you believe JBM is your perogative as it is for the wider audience to whom I addressed the post. Just thought other readers might find the calorific challenges that wasps face interesting.

Something for you to ponder JBM just in case it has escaped you. It's not much of a sales pitch persuading people of the value of wasps and the need to preserve them? If I were 'selling' to the forum, don't you think I would have availed myself of the commercial pages and advertised directly?

 

[Wilco]

I was going to let this rest not wanting to deny you the obvious pleasure you get from belittling other contributors on the forum but on reflection I think that folk might find the background to this a fascinating doff of the cap to the amazing industry of hymenopterans. So, not for your benefit JBM, but for the interest of others:

When I first embarked on my journey studying and researching wasps and their behaviour back in 2002 I came across an old reference which stated that an average wasp nest would eradicate between 4 and 5 metric tonnes of insect prey. Much as JBM (and Serian Sumner by all accounts) disbelieve this today, so I disbelieved the quote when I first encountered it assuming that it was a typo and should have read 4 to 5 kilos instead. So I set about trying to verify that the author actually meant 4 to 5 kilos only to discover that 4 to 5 kilos of fresh weight of insect prey came nowhere close to satisfying the nutritional requirements of wasps. My bad, and something that I continue to pay for, is that I lost the original reference when my computer was corrupted by malware and so I accept that I deserve all of the ridicule JBM et al dish out to me, not because of the subject matter but because I was sloppy and know better not to fail to secure references which I subsequently go on to quote.

Anyway, enough of setting the scene. Here's the interesting bit:

Nowhere in the circa 800 scientific papers on wasps that I have digested could I find the daily calorific consumption of wasps. However, I was able to find references to the daily calorific consumption of honeybees and for the purposes of today, I'll cite this reference:

https://weblessons.us/docs/farmdocs/apiary/Honey-Bee-Nutrition-by-Zachary-Huang.pdf
The reference states that a worker honeybee requires about 11mg of dry sugar per day. Honeybees are not that dissimilar to wasps in terms of average body mass, i.e. 114mg body mass for the honeybee vs 84mg body mass for Vespula vulgaris (Common wasp).

Rearing Honey Bees, Apis mellifera, in vitro 1: Effects of Sugar Concentrations on Survival and Development (Honeybee control body mass circa 114mg)

Does size matter? – Thermoregulation of ‘heavyweight’ and ‘lightweight’ wasps (Vespa crabro and Vespula sp.) (Common wasp body mass circa 84mg)

It would not be unreasonable to estimate the calorific requirement of wasps as a proportion of dry sugar by average body mass of the two insects, i.e. 11mg x 84/114 = 8.1mg dry sugar per day per wasp. Wasps are naturally busy insects spending quite a bit of time flying but it could be argued that honeybees work harder so reducing this figure to 0.8mg of dry sugar per day per wasp (i.e. 1/10th the activity of a worker honeybee) would be more than a cautious estimate.

The typical nest size for Vespula vulgaris is circa 5000 wasps meaning that the daily calorific requirement for the nest would be of the order of 0.8mg x 5000 = 4g of dry sugar per day. That really doesn't sound like much but here's the thing.

During the hunting phase which may last from May to October, adult wasps in the nest will be ostensibly fed by the process of trophallaxis. The larvae in the nest are fed by the adults with insect prey rich in fats, proteins and some sugars (predominantly chitin). The wasp larvae digest that insect prey and then regurgitate the sugars as trophallactic liquid to feed the adult wasps in return. The following reference clearly demonstrates that larval saliva predominantly contains carbohydrates as a source of calorific energy.

Similarity of Amino Acids in Nectar and Larval Saliva: The Nutritional Basis for Trophallaxis in Social Wasps on JSTOR (circa 9% carbohydrate content for Vespula vulgaris)

We know that during the hunting phase the carbohydrates used to power the wasp nest principally come from digested insect prey. (Note this applies to the UK and not antipodean territories).

The question that needs to be answered is how much carbohydrate is there in the average insect which is where this reference is useful:

https://www.researchgate.net/publication/305396814_Nutritional_and_sensory_quality_of_edible_insects
The reference cites the figure of 49.8mg of carbohydrate per Kg of fresh weight of insects as the upper figure. Using this upper figure provides for a cautious estimate of the fresh weight of insects required to power a wasp nest on a daily basis, i.e. 4g/49.8mg or 4g/0.0498g = 80Kg!

80Kg per day over the space of 6 weeks works out to be 3.6 metric tonnes of fresh weight of insects.

Fresh weight is effectively the weight of insects eradicated by wasps and should not be confused with payload weights which are frequently quoted in some scientific papers.

Taking the argument the other way, i.e. starting from a figure of 8Kg per annum per nest taken from this reference:

https://www.itv.com/news/2016-06-10/experts-create-a-buzz-as-they-reveal-why-we-should-love-wasps
8Kg of fresh weight of insect prey will provide 49.8mg x 8 = 398.4mg or 0.398g of carbohydrate.

That's 8Kg of insects for the whole season for a nest. Taking a season to be 6 weeks this is equivalent to 0.398g/42 = 0.009g of carbohydrate per day per nest or
0.009g/5000 = 0.0000018g or 0.0018mg per wasp per day.

Given that a honeybee consumes about 11mg of dry sugar a day I find it hard to believe that a wasp gets by with 0.0018/11 = 1/6000th of the calorific requirement of a honeybee.

As I have repeated many times, my bad for losing the original reference but no matter what method I use to verify the original quote, be that calorific or physical payloads and activity, I keep getting answers of similar magnitude to the original quote.

I guess it's time for the predictable fun to start.

I've not fact checked the figures here but some initial thoughts spring to mind:

The first consideration is that insects are not the sole source of carbohydrate for wasps- they do visit flowers during part of the season where they can collect both protein and carbohydrates. So carbohydrate needs through predation are likely to be lower.

Secondly (minor) my understanding was that predation was more linked to protein requirements than carbohydrate ones.

Thirdly, comparisons of metabolic requirements based on scaling are inherently more complex than just reducing (and 114:84 is about a 25% difference so fairly significant). Don't go killing elephants.

Fourthly, it's entirely possible (or even probable) that the original reference was wrong or spurious although without access to it it's hard to investigate.

The concept of 5000 wasps at 84mg each suggests there are around 420g of wasps in an average colony. A few kilos of insects predated on over a season seems plausible. This could still be tens of thousands of bugs.

 

[Karol]

I've not fact checked the figures here but some initial thoughts spring to mind:

The first consideration is that insects are not the sole source of carbohydrate for wasps- they do visit flowers during part of the season where they can collect both protein and carbohydrates. So carbohydrate needs through predation are likely to be lower.

They do but this tends to be in the Spring before there is sufficient brood in the nest to sustain the adults and then in the autumn when wasps convert to sweet feeding proper. We see very little sweet feeding in late spring and summer whilst the brood is being developed and this manifests itself quite evidently because our traps which are sweet baited only catch in spring and autumn. We catch no wasps during their hunting phase.

If one looks at the scientific literature on the division of labour within the nest, then one gets about 20 to 30% of worker wasps hunting so arguably the figure could be 1/3rd but that would still be about a metric tonne in the above model. Interestingly the literature that I have seen doesn't take into account where the wasps are in their lifecycle so division of labour assessments appear to be skewed.

Secondly (minor) my understanding was that predation was more linked to protein requirements than carbohydrate ones.

That's my understanding as well but that is to provision the brood. The adult wasps need reward and it's biologically efficient that that should come from larval trophallaxis. It means that adult wasps can concentrate on hunting for prey for brood development.

Thirdly, comparisons of metabolic requirements based on scaling are inherently more complex than just reducing (and 114:84 is about a 25% difference so fairly significant). Don't go killing elephants.

Agreed but I've scaled down activity by 90% on top of that. Research papers that I have seen suggest that wasp activity in the nest is proportionate to the availability of prey so there are lots of chickens and eggs that significantly impact on the estimations.

Fourthly, it's entirely possible (or even probable) that the original reference was wrong or spurious although without access to it it's hard to investigate.

Could not agree more and that was my initial thinking which is why I have spent so much time looking to corroborate or dispell the original reference.

The concept of 5000 wasps at 84mg each suggests there are around 420g of wasps in an average colony. A few kilos of insects predated on over a season seems plausible. This could still be tens of thousands of bugs.

A few kilos dry weight perhaps. But fresh weight is another matter especially because wasps pare away substantial parts of their kill so much of it doesn't get back to the nest. The other thing to remember is that all this weight (carbs and fats) simply gets converted to Carbon Dioxide and water which is exhaled to the atmosphere. So proportionately speaking there is very little residual mass save for the proteins (amino acids) that are used to build structure.

 

[Wilco]

They do but this tends to be in the Spring before there is sufficient brood in the nest to sustain the adults and then in the autumn when wasps convert to sweet feeding proper. We see very little sweet feeding in late spring and summer whilst the brood is being developed and this manifests itself quite evidently because our traps which are sweet baited only catch in spring and autumn. We catch no wasps during their hunting phase.

If one looks at the scientific literature on the division of labour within the nest, then one gets about 20 to 30% of worker wasps hunting so arguably the figure could be 1/3rd but that would still be about a metric tonne in the above model. Interestingly the literature that I have seen doesn't take into account where the wasps are in their lifecycle so division of labour assessments appear to be skewed.


That's my understanding as well but that is to provision the brood. The adult wasps need reward and it's biologically efficient that that should come from larval trophallaxis. It means that adult wasps can concentrate on hunting for prey for brood development.



Agreed but I've scaled down activity by 90% on top of that. Research papers that I have seen suggest that wasp activity in the nest is proportionate to the availability of prey so there are lots of chickens and eggs that significantly impact on the estimations.



Could not agree more and that was my initial thinking which is why I have spent so much time looking to corroborate or dispell the original reference.



A few kilos dry weight perhaps. But fresh weight is another matter especially because wasps pare away substantial parts of their kill so much of it doesn't get back to the nest. The other thing to remember is that all this weight (carbs and fats) simply gets converted to Carbon Dioxide and water which is exhaled to the atmosphere. So proportionately speaking there is very little residual mass save for the proteins (amino acids) that are used to build structure.

A large honeybee colony of >40,000 bees might collect a tonne of nectar and pollen, feed much to brood and dehydrate the rest of the nectar down for honey. I remain unconvinced that a colony of wasps a fraction of that size would get through the same weight in insects.

 

[Amari]

My head is hurting......

 

[Karol]

My head is hurting......

To translate ; if we get rid of wasps (injudiciously) we get tonnes more pests which promotes the use of pesticides (which makes agrochem happy) which also harm bees probably in excess of the harm caused by wasps to bees. Ergo, the alternative of integrated wasp management which utilizes wasps for their value and at the same time manages them as a nuisance in an ecologically rational and sensitive way which is better for honeybees in the long run.

After that the numbers don't really mean much other than a bit of w*lly waving.

 

[JamezF]

Does 80kg live weight of insects per day seem plausible for a nest of 5,000 foragers?

If my maths is correct that would work out at 16g per wasp per day? I've no idea what the weight of the average kill might be, but I know they take a lot of caterpillars when they're really quite small, so not a large percentage of the wasp's own bodyweight.

If we said that the wasp would only take prey no more than half its own bodyweight, the 16g would take about 380 trips to collect. Over an eighteen hour flying day that would mean each trip would have to be less than three minutes, without allowing any time for feeding or whatever else. And assuming all 5,000 wasps are looking for food rather than collecting wood, say. If only one third are foraging for food then obviously the time available per kill is even smaller.

Assuming I've done my maths correctly that seems unlikely given the way I often see wasps hunting through plants for prey. They can take quite a while to find a target.

Perhaps this is too simplistic a way to look at the process?

So I'll propose an alternate simplification

Let's say the wasps are foraging over a period of 180 days, with 40 days of maximal foraging activity in the middle linearly tapering to nothing in the 70 days either side. To achieve a tonne of live-weight kills over the season, what maximal kill rate is required? I make that just over 9kg per day ( 70 x 9kg / 2 + 40 x 9kg + 70 x 9kg / 2 = 990kg ). A maximum rate of 9kg per day might seem more feasible. A hunting force of 2,000 wasps would need to find 4.5g each to hit that target. Based on the above assumptions that would require around 107 trips allowing ten minutes per kill. That seems far more achievable though I still feel it's doubtful, particularly given that both daylight hours and the size of the hunting force (and perhaps even available prey) will be reduced outside the middle 40 days. I wonder if there might be lots of other activity (or inactivity) happening that also makes this figure implausible.

I'm not sure I buy the 8kg figure either however on the basis of the ITV web page, because the way it's written doesn't suggest to me that the journalist doing the writing has necessarily understood the information they've been given. As has already been pointed out, there could be quite a difference between the answers to "What weight of prey does a wasp's nest consume?" and "What weight of prey is a wasp's nest responsible for killing?" I'm not for a moment suggesting that Dr Sumner has given an incorrect answer, but rather that it may have been misconstrued.

James

 

[Nannysbees]

My head is hurting......

And mine!!!!!!

 

[Karol]

Does 80kg live weight of insects per day seem plausible for a nest of 5,000 foragers?

If my maths is correct that would work out at 16g per wasp per day? I've no idea what the weight of the average kill might be, but I know they take a lot of caterpillars when they're really quite small, so not a large percentage of the wasp's own bodyweight.

If we said that the wasp would only take prey no more than half its own bodyweight, the 16g would take about 380 trips to collect. Over an eighteen hour flying day that would mean each trip would have to be less than three minutes, without allowing any time for feeding or whatever else. And assuming all 5,000 wasps are looking for food rather than collecting wood, say. If only one third are foraging for food then obviously the time available per kill is even smaller.

Assuming I've done my maths correctly that seems unlikely given the way I often see wasps hunting through plants for prey. They can take quite a while to find a target.

Perhaps this is too simplistic a way to look at the process?

So I'll propose an alternate simplification

Let's say the wasps are foraging over a period of 180 days, with 40 days of maximal foraging activity in the middle linearly tapering to nothing in the 70 days either side. To achieve a tonne of live-weight kills over the season, what maximal kill rate is required? I make that just over 9kg per day ( 70 x 9kg / 2 + 40 x 9kg + 70 x 9kg / 2 = 990kg ). A maximum rate of 9kg per day might seem more feasible. A hunting force of 2,000 wasps would need to find 4.5g each to hit that target. Based on the above assumptions that would require around 107 trips allowing ten minutes per kill. That seems far more achievable though I still feel it's doubtful, particularly given that both daylight hours and the size of the hunting force (and perhaps even available prey) will be reduced outside the middle 40 days. I wonder if there might be lots of other activity (or inactivity) happening that also makes this figure implausible.

I'm not sure I buy the 8kg figure either however on the basis of the ITV web page, because the way it's written doesn't suggest to me that the journalist doing the writing has necessarily understood the information they've been given. As has already been pointed out, there could be quite a difference between the answers to "What weight of prey does a wasp's nest consume?" and "What weight of prey is a wasp's nest responsible for killing?" I'm not for a moment suggesting that Dr Sumner has given an incorrect answer, but rather that it may have been misconstrued.

James

Thank you James. It's refreshing to get a thoughtful and objective response.

I think you are absolutely right about things being misconstrued which is why I have been careful not to criticise Professor Sumner not least because I don't do heresay (save for when I lose references ). I also agree with you that the 8Kg figure per annum is questionable. I suspect that that figure has been taken from studies done in New Zealand which firstly do not translate to the situation in the UK and secondly from what I can see were performed during the sweet feeding phase so under reported prey foraging.

Going back to your 16g per day per wasp that equates to wasps killing as few as 12 large caterpillars each per day. The 380 trips is plausible but I would suggest an over simplification and overestimation for a number of reasons. Firstly, kill weight is not, as you quite rightly point out payload weight. Secondly, payload weight in wasps has been studied and wasps have been seen to lift their own body weight which would halve the number of trips. Thirdly, wasps navigate back to residual food sources once found so less time lost foraging. Fourthly, adult wasps are fed by their larvae as and when they deposit prey to the brood so there is little lost time as adult wasps literally feed on the go. Fifthly, the body mass that I quoted for wasps was a 'control' weight. The paper I quoted from cited body mass as much as 50% more for well provisioned wasps so more prey equals bigger wasps. Finally, wasps also take a lot of insect carrion for example dead honeybees. One doesn't often see dead insects lying around.

At maximal foraging when sexual brood is being provisioned the trip rate in an average 5000 wasp nest will be of the order of circa 60,000 trips per day, i.e. about 12 trips per wasp per day, i.e. less than 1 per hour. (Based on personal observation when doing field research as corroborated by pest control professionals in the field). Research literature on wasp dwell times in a nest (from memory) suggests one flight every 18 minutes per wasp so there is plenty of scope to triple the trip rate to 180,000 trips per day. As previously stated, wasp activity reflects availability of prey. The more prey available the more wasps will take. It's also not unusual to find nests of 20,000 wasps in the UK. Antipodean nests on the other hand have been found with hundreds of thousands of wasps per nest.

My personal take on this is that there are so many variables that it makes it a nonsense to derive a meaningful figure. Angels dancing on a pin head. However, understanding the magnitude of wasp predation is essential in my view because wasps provide a method for greener pest control when it comes to crop management which requires an understanding of their value to win the argument against the likes of big argochemical company spin on pesticides.

 

[Erichalfbee]

Well, I’ve asked Professor Sumner to have a look at this thread. She may not bother though.

 

[The Poot]

Well, I’ve asked Professor Sumner to have a look at this thread. She may not bother though.

Personally, I wouldn‘t blame her in the least.