There are numerous species of wasps and most of them are unknown to many people. They are known as solitary wasps and to us are quite harmless, but to caterpillars, aphids and saw flies they are lethal. Mention of wasps and we automatically think of the yellow and black species, the social wasps. These are well capable of overpowering larger prey, such as honey bees.
Social wasps forage for their vital supplies which consists of 4 basic necessities:
nest building materials – wood fibres chewed into a pulp
water – from any nearby source to drink and mix to make pulp
food for their young – adult wasps capture and masticate animal protein in the form of prey insects, including caterpillars, aphids, horseflies, bluebottles, honey bees, or scavenging dead animals/birds
food for themselves – as they are unable to digest the food items they catch for their young, they instead rely upon carbohydrates usually from sweet liquids, such as nectar and honey dew. They also drink water. A primary source of their carbohydrates during the nesting season, is a sweet liquid fed to them by their young grubs which they tend in the nest. African wild dogs, wolves and some birds adopt this behaviour which is basically regurgitating stored food. Nice! This behaviour is known as trophallaxis behaviour.
In scientific terms it means the mutual exchange of regurgitated liquid/foods between adults or between themselves and their young. In the case of wasps, this liquid is laced with chemicals to make it extremely attractive to attendant adults, including fructose, sucrose and glucose, hence its sweet taste! In fact some scientists stated that the attraction of this larval secretion was the raison d’etre of wasp sociality, whilst others dismiss this argument.
Hunting for their prey
How do they find their prey? They are opportunists and generalist predators, not relying upon a few species as prey items. They use a variety of methods to find it and select it. They forage alone and use a variety of strategies to obtain the food needed and can be influenced by past successful forays, by the presence of other wasp foragers on resources or other forages such as flies, by their ability to learn odours, their ability to remember visual landmarks and by their ability to recognise odours and visual signs of leaf damage to plants, (caused by caterpillars) are methods certainly used. Thus when wasps find an abundant resource, i.e. there are many insects/grubs/food etc., all located en masse, then news will get back, one way or another to other wasps, even from other nests and in a short time, numerous wasps may descent on the new food source.
I was watching a wasps as it rested on a wooden upright support, near to the above busy hives. It was nonchalantly cleaning itself. Later I realised it was actually watching a honeybee just a few inches away that was also cleaning itself. The wasp and bee where within a few feet of the hives.
Either way, for a wasp to fly near to an active honey bee hive, where there may be 30-40,000+ honeybees, find a nearby observation post, watch the bees, sit and wait in full view of the busy honey bees, find one bee grooming itself, attack it, kill it and carve it up, is some risk to take for a sweet drink!! The bees were that busy they did not see this happening on the ground near their hives. This ‘ambush’ must be a better strategy for wasps as I have also watched wasps flying around the hive entrances and be chased away by numerous honey bees.This wasp has likely learnt this strategy is a safer and more productive one to take and may have done this several times before.
The wasp will first dissect the bee, even whilst it still may be living, remove its wings, remove its head, thorax and abdomen. Then it will chew up the body part it is going to carry back to its nest, carry as much of it as it can in one mouthful, return to its handy work and again carry away what it can manage and do this until there is no viable and useful food left. I note that I have never seen them carry away wings ! The protein rich food will be fed to the hungry growing wasp grubs in its nest.
This wasp used another strategy, first it attacked and injured the honey bee and waited for it to weaken before dismembering it, unlike the above wasp that attacked and dismembered immediately. In return for this violent and dangerous action what does the wasp get in return?
By teasing the mouth parts of the wasp grubs, adults wasps drink the resulting sweet liquid produced by the teased grub. Ants do something similar with aphids. Out foraging is labour intensive so coming across numbers of aphids, which ants could eat, instead though they gently stroke the body of the aphids with their antennae, the aphid excretes a sweet liquid called honeydew from its backside, a protection droplet of honeydew and the ant drinks the liquid. The ants then protect the aphids from predators. In some circumstances though, the fact that the ants ‘force’ the ‘protection droplet’, may have a knock on effect for the aphid which may not be as effective in reproduction. But hey, it is better to produce less or smaller offspring than be eaten by an ant or some other predator!!
Here is a video of wasps cooperating in killing and dismembering a honey bee
Besides my own experiences and observations…..
James H, et al (1982) “Similarity of amino acids in nectar and larval saliva: the nutritional basis for trophallaxis in social wasps”, Evoltion, 36 (6) pp 1318-1322
Stadler B, Dixon A F G, (2008), “ Mutualism: ants and their insect partners”, Cambridge University Press, Cambridge