Wasps

[Karol]

It seems unusual that wasps would expend extra energy bringing back whole abdomens just to extract possible nectar contents.

On the face of it possibly, but not when you factor in inter colony competition. Wasps expend vast amounts of energy competing with each other for the same food sources. A discrete packet of energy such as an abdomen full of nectar then becomes a boon because the energy taken to remove an abdomen and fly off with it is relatively small compared to fighting other wasps for it.

From the study below, there is no clear trend in the load composition of wasps (inc. V. germanica) scavenging bee corpses ...

But then the study does not examine the effects of life cycle on foraging behaviour. During the hunting phase (i.e. immature nest with grubs) one would expect wasps to concentrate on the whole body as protein (for grub development) is concentrated in the head and thorax. The abdomen is virtually hollow. I don't concur with the paper when it states that exoskeletons are of little nutritional value. The exoskeleton is made of chitin which is a complex sugar that grubs do digest (and then re-feed back to the adults as simple sugars). I suspect that the limbs are paired away because they increase drag during flight. During the sweet feeding phase (mature nest with no grubs) adult wasps are solely interested in sweet liquid foods. A wasp would have to expend a significant amount of energy to collect the same amount of nectar contained in a bee abdomen! Again, snipping it off to carry it away to be consumed somewhere in privacy rather than at a hive where competition will be 'focused' and 'high' makes biological sense.

Load-Lifting Capacities of Three Species of Yellowjackets (Vespula) Foraging on Honey-Bee Corpses http://www.jstor.org/discover/10.2307/2390561?uid=3738232&uid=2134&uid=4581118267&uid=2&uid=70&uid=3&uid=4581118257&uid=60&sid=21102638299987

 

[sharonh]

I bought a wasp bane trap for beside my two colonies, wasps can't get out once in. I wouldn't put any low efficiency trap beside them incase the scouts would get out & back to alert others. I have low efficiency traps set the other end of my garden, & they trap alot of wasps, which I empty out every morning so they won't be able to crawl over any dead ones. Wish at this stage that they were gone, would have loved to have found the nests, as would have been easier to rid all together.

 

[PBee]

....... A discrete packet of energy such as an abdomen full of nectar then becomes a boon because the energy taken to remove an abdomen and fly off with it is relatively small compared to fighting other wasps for it.
......A wasp would have to expend a significant amount of energy to collect the same amount of nectar contained in a bee abdomen! Again, snipping it off to carry it away to be consumed somewhere in privacy rather than at a hive where competition will be 'focused' and 'high' makes biological sense.

Michael E. Archer seems to be one of the recognised authorities on wasps. He makes no mention of such a unique behaviour in recent U.K. based research on foraging V. vulgaris .....

The main materials brought into a wasp colony by the workers are usually called pulp or wood pulp, prey or flesh, nectar and tree-sap, and water (Edwards,1980; Jeanne,1999). The pulp and flesh are carried by the mandibles and the nectar, tree-sap and water in the crop.

... http://www.academia.edu/4149439/Observation_on_marked_foragers_of_Vespula_vulgaris_L._Hym._Vespidae_in_England._2004

 

[Karol]

Michael E. Archer seems to be one of the recognised authorities on wasps. He makes no mention of such a unique behaviour in recent U.K. based research on foraging V. vulgaris ..... ... http://www.academia.edu/4149439/Observation_on_marked_foragers_of_Vespula_vulgaris_L._Hym._Vespidae_in_England._2004

Professor Archer is very well recognised in this field. If you read the paper carefully and "http://www.academia.edu/4304545/Seasonal_foraging_characteristics_during_mid-day_of_successful_underground_colonies_of_Vespula_vulgaris_Hymenoptera_Vespidae_in_England_2000" also by Michael Archer what you'll see is that foraging activity is linked to nest maturation (ranging from August to October) and that after maturation foragers become almost entirely 'fluid' carriers consistent with sweet feeding.

I did not say that wasps taking bee abdomens would take them back to their nest! Just that I have a suspicion (based on field observations) that during the sweet feeding phase, wasps take bee abdomens as a source of nectar which they consume elsewhere to avoid competition with other wasps (from other colonies). In terms of the research cited in the 2000 paper any wasps participating in such behaviour would return as 'fluid' carriers'. The 2004 paper which you quote cites work conducted in the 1970's which was all performed in July (immature nests) when wasps were hunting and therefore such behaviour would in any case not have been observed.

 

[sharonh]

On the face of it possibly, but not when you factor in inter colony competition. Wasps expend vast amounts of energy competing with each other for the same food sources. A discrete packet of energy such as an abdomen full of nectar then becomes a boon because the energy taken to remove an abdomen and fly off with it is relatively small compared to fighting other wasps for it.



But then the study does not examine the effects of life cycle on foraging behaviour. During the hunting phase (i.e. immature nest with grubs) one would expect wasps to concentrate on the whole body as protein (for grub development) is concentrated in the head and thorax. The abdomen is virtually hollow. I don't concur with the paper when it states that exoskeletons are of little nutritional value. The exoskeleton is made of chitin which is a complex sugar that grubs do digest (and then re-feed back to the adults as simple sugars). I suspect that the limbs are paired away because they increase drag during flight. During the sweet feeding phase (mature nest with no grubs) adult wasps are solely interested in sweet liquid foods. A wasp would have to expend a significant amount of energy to collect the same amount of nectar contained in a bee abdomen! Again, snipping it off to carry it away to be consumed somewhere in privacy rather than at a hive where competition will be 'focused' and 'high' makes biological sense.

Thanks Karol for all the information on wasps and their behavior . This year seems really bad around here compared to previous. I wish they were gone at this stage. I know you said it could be another six weeks, but would the queen wasp be still laying ?

 

[Karol]

Thanks Karol for all the information on wasps and their behavior . This year seems really bad around here compared to previous. I wish they were gone at this stage. I know you said it could be another six weeks, but would the queen wasp be still laying ?

Now there's a question!

If you've got wasps taking bees, i.e. snipping off the limbs and wings, then the chances are that there are still grubs in the nest so the queen could in theory still be laying. This would not be unusual. Wasp nest maturation is weather (and food) dependant and can occur at any time between the end of July and the beginning of November. I suspect that from your postings, you have hunting wasps in which case there may still be worse to come.

We have observed queens start laying again a number of weeks after nest maturation (i.e. a second procreative litter) but this is unusual and we've only ever observed it twice (and in both cases we had really harsh winters) so I think this is an unlikely scenario for this year but one never quite knows with wasps. If it does happen and we have a harsh winter then we could be in for an even more pronounced wasp season next year - this year is not actually a peak year for wasps (it's only about 50% of previous peak years!)

 

[PBee]

......

I did not say that wasps taking bee abdomens would take them back to their nest! Just that I have a suspicion (based on field observations) that during the sweet feeding phase, wasps take bee abdomens as a source of nectar which they consume elsewhere to avoid competition with other wasps (from other colonies).........

So you have observed wasps landing with an abdomen, apparently removing crop contents, and leaving without the carcase?

The incidence of bee corpses with full honey crops must be fairly low. Foragers transfer crop contents directly to a number of younger receiving bees on return and they in turn share with other nest mates etc.

 

[Karol]

So you have observed wasps landing with an abdomen, apparently removing crop contents, and leaving without the carcase?

No. Read my posts again. Two different situations. One where wasps take whole carcasses minus limbs. One where wasps only take the abdomen and leave the rest of the bee. What we have observed in the latter is bees left to die slow deaths without their abdomens and we have observed this late in the season when wasps were otherwise sweet feeding.

The incidence of bee corpses with full honey crops must be fairly low. Foragers transfer crop contents directly to a number of younger receiving bees on return and they in turn share with other nest mates etc.

Unless the bees have died from starvation then I doubt that their abdomens would be devoid of nectar/honey and it's not just the crop but the gut that's involved as well.

 

[sherwood]

I too have seen wasps picking off bees as they attempt to enter the hive rather than exit. I have so far despite all precautions lost 4 colonies to these menaces this year. It is extremely awkward when you want to feed the colonies yet these b*****ds are still around.

 

[sharonh]

I too have seen wasps picking off bees as they attempt to enter the hive rather than exit. I have so far despite all precautions lost 4 colonies to these menaces this year. It is extremely awkward when you want to feed the colonies yet these b*****ds are still around.

Hi sherwood, that's awful to have lost so many to them. I can't stand them. I have tried everything to keep them away & there are so many around, thought it would ease off at this time of the year . Karol stated it could be another six weeks before there gone. Hope you have no more loses.

 

[PBee]

No. Read my posts again. Two different situations. One where wasps take whole carcasses minus limbs. One where wasps only take the abdomen and leave the rest of the bee. What we have observed in the latter is bees left to die slow deaths without their abdomens and we have observed this late in the season when wasps were otherwise sweet feeding.
........

The two different situations you describe both appear to describe flesh feeding, with load size determined largely by the carrying capabilities of different individual wasps/species. From a paper by J.B. Free .....

While foraging on dead adult and pupal honeybees, individual wasps showed little conformity in the order in which they dismembered their prey; they attempted to take as large loads as possible and preferred abdomens and thoraces to heads. http://link.springer.com/article/10.1007%2FBF02223769

Of the three discrete periods in colony development queen, small cell and large cell colony, Archer has this to say about the large cell phase ...

From the middle of August until late October the large-cell colony is built, although most of the building is completed by the latter part of September (40 days). Although these three divisions are only approximately equal in length it would seem that earth and pulp carriers and empty incomers occur predominately during the small-cell colony phase, and the flesh and fluid carriers during the large-cell colony phase. http://www.academia.edu/4304545/Seasonal_foraging_characteristics_during_mid-day_of_successful_underground_colonies_of_Vespula_vulgaris_Hymenoptera_Vespidae_in_England_2000_

If flesh collection does not cease completely in the time scale under discussion, then without actually observing wasps extracting nectar from abdomens away from the collection site, or empty abdomens being ejected from the nest, there does not seem to be any evidence to support your theory.

 

[Karol]

The two different situations you describe both appear to describe flesh feeding, with load size determined largely by the carrying capabilities of different individual wasps/species. From a paper by J.B. Free .....

Both do describe flesh feeding except that abdomen removal was observed by germanica (i.e. larger of the species) during the sweet feeding phase when previously largely whole carcasses were being taken during the hunting phase.

Of the three discrete periods in colony development queen, small cell and large cell colony, Archer has this to say about the large cell phase ...

And your point is?

If flesh collection does not cease completely in the time scale under discussion,

That's quite an interesting assumption! Who says it hasn't?

then without actually observing wasps extracting nectar from abdomens away from the collection site,

which is why I carefully chose the word 'suspicion'...

or empty abdomens being ejected from the nest,

there's that assumption again that the abdomens are taken back to the nest. I agree that they are during colony development i.e. during the hunting phase (which can extend up to November depending on weather or finish as early as the beginning of September) but that does not automatically extrapolate into the 'sweet feeding' phase when wasps stop hunting to concentrate on carbohydrates once the nest has finished developing.

there does not seem to be any evidence to support your theory.

If it makes you happy to say so.

 

[PBee]

Both do describe flesh feeding except that abdomen removal was observed by germanica (i.e. larger of the species) during the sweet feeding phase when previously largely whole carcasses were being taken during the hunting phase.
........

there's that assumption again that the abdomens are taken back to the nest. I agree that they are during colony development i.e. during the hunting phase (which can extend up to November depending on weather or finish as early as the beginning of September) but that does not automatically extrapolate into the 'sweet feeding' phase when wasps stop hunting to concentrate on carbohydrates once the nest has finished developing.
........

Your statements seem contradictory. In both the Free (1970) and Coelho and Hoagland (1995) papers already linked, V. germanica is described as only occasionally taking whole bees. The latter paper also quotes Archer and Spradbury stating that worker size increases as the season progresses, so load sizes should increase as the season does. Coelho, in the recently published Predation in the Hymenoptera: An Evolutionary Perspective, 2011

V. germanica, being the largest species, was occasionally able to carry an entire bee corpse; however, when it was unable to do so, it chewed through the narrowest portions of the body—the petiole and cervix. Hence, discrete tagmata of the bee corpse were taken.

I would be interested in the nature and extent of your observations. For example, did you observe at beehives or baiting stations, the period and frequency of observations and when the behaviour changed etc.

 

[Karol]

Your statements seem contradictory.

In what way?

In both the Free (1970) and Coelho and Hoagland (1995) papers already linked, V. germanica is described as only occasionally taking whole bees.

I didn't say whole bees I said largely whole carcasses, i.e. with limbs and wings removed.

The latter paper also quotes Archer and Spradbury stating that worker size increases as the season progresses, so load sizes should increase as the season does. Coelho, in the recently published Predation in the Hymenoptera: An Evolutionary Perspective, 2011

It's not my experience that worker size increases as the season progresses. In filming embryonic nests the first cohort of workers have been the same size as latter season workers. In all the behavioural field work I've done I've not seen any appreciable change in worker wasp dimensions within the same nest and monitoring programmed swarm feeding is a good way to detect variations in size.

I would be interested in the nature and extent of your observations. For example, did you observe at beehives or baiting stations, the period and frequency of observations and when the behaviour changed etc.

More than 13 years at the coal face observing and filming wasps in just about every situation going including bee hives, primary hunting terrains, water bearing, pulping, sweet foraging, nesting, mating, hibernation, dissection, etc etc. not to mention population and behavioural studies etc etc. Per annum I would say I've averaged a few hundred hours contact time spanning the whole year from hibernation to hibernation and everything in between. I lecture for probably 240 hours per annum. I've digested somewhere in the region of 700 papers now (a lot of which are poor science). Best video footage captured - grubs re-feeding adults within a nest. And no, I've not published anything in any of the recognised journals and have no plans to do so. Given that my back ground is pharmaceutical research I'm content with the scientific rigour of my own work for my own purposes. As for germanica taking bees then the striking case I best recall was in Lubeck in Germany 2004, second week in September, where behaviour changed almost overnight, i.e. early in the week germanica wasps were noticeably taking most of the carcass with a fair bit of beheading and then over the space of literally a couple of days just the abdomens were taken. Not only that but carbohydrate monitoring stations were ignored (by and large save the odd opportunist) during the hunting phase and then after the switch the monitoring stations were inundated. I don't have proof that the abdomens are taken during sweet feeding for their carbohydrate content which is why it remains merely a suspicion but I can't see how it would be any different to a wasp attacking a grape. Don't suppose Archer et al have witnessed wasps carrying grapes back to the nest do you know? I don't plan to do anything else about it because it's not going to change my world finding out one way or the other.

 

[user 6228]

.... I've digested somewhere in the region of 700 papers now (a lot of which are poor science). ....

I would concur that when reading papers, that one does need to have a critical eye on the science portrayed. In my own field, I have a similar issue of finding research done with sufficient rigour.

 

[Gilberdyke John]

I would concur that when reading papers, that one does need to have a critical eye on the science portrayed. In my own field, I have a similar issue of finding research done with sufficient rigour.

Amen to that. It is all too easy for researchers and authors to fall into the trap of interpreting their findings and measurements to fit their own opinions.
Any paper should be read from a sceptical position until truly satisfying ALL the circumstances.

 

[AdrianSmith]

Amen to that. It is all too easy for researchers and authors to fall into the trap of interpreting their findings and measurements to fit their own opinions.
Any paper should be read from a sceptical position until truly satisfying ALL the circumstances.

Or even posts from people who might be trying to sell something

This is quite a fun read - scarier and more dangerous than wasps, and every bit as relevant to beekeepers:
http://www.dhmo.org/facts.html

 

[theeggman]

Or even posts from people who might be trying to sell something

Sorry Adrian, I think you are out of order here. You've been on the forum long enough to know there was an issue when the member came on to the forum but since then I think his 'expert' knowledge is of benefit to the rest of us, and he hasn't tried to plug his product. I haven't bought his trap but have been grateful for his input.

Tim.

 

[Dishmop]

Luckily I have never had a problem.. Might be something to do with being in a residential area perhaps.
This time of year I see the odd one skimming the grass looking for prey, but if they get too close to a hive they soon get a "jolly good thrashing" from the bees.

 

[mbc]

Or even posts from people who might be trying to sell something

Sorry Adrian, I think you are out of order here. You've been on the forum long enough to know there was an issue when the member came on to the forum but since then I think his 'expert' knowledge is of benefit to the rest of us, and he hasn't tried to plug his product. I haven't bought his trap but have been grateful for his input.

Tim.

Well, sorry Tim, but I think there is a constant background of subliminal plugs whenever this (self proclaimed "I've not published anything in any of the recognised journals and have no plans to do so") 'expert' posts on threads about wasps, and Adrian has done well to see it and bring it to light, not "out of order" at all IMHO.
Its a shame we dont have a real wasp expert who could call out any rubbish when its posted, I've nothing against Karol and enjoy reading his posts but IMHO he has been found out on a few threads (mostly about pesticides) stating his opinion and faulty thinking as if they were facts.