Wasps start to ‘sweet feed’ when their nest matures and there are no more grubs left in the nest that require protein. In the UK the earliest that this happens is about the third week in July and the latest that this has been observed is in early November.
Sweet feeding wasps represent the most likely challenge to a bee hive. In nature there are comparatively few naturally occurring sources of sugar so wasps are forced to compete with each other over these rare resources. This gives rise to specific wasp behaviour whereby scouting wasps that find a source of sugar will recruit their colleagues and together the wasps work as a team to defend the food source from other wasps whilst they themselves consume it. This behaviour leads to swarm feeding and can have a catastrophic impact even on healthy bee hives when wasp populations are at their peak.
Wasps are efficient insects which means that once they find a food source they will keep returning to it until it is completely exhausted. This leads to ‘programmed’ feeding where wasps will ignore other food sources until they have consumed all of the existing food source. Wasps have extraordinary pin point navigational skills and will keep coming back to the exact same location where they found food literally to within millimetres. This essentially means that once wasps have latched onto a food source you can’t entice them away which makes trapping them very difficult.
There are two principal sources of sugar that attract sweet feeding wasps to the bee hive. Honey is the obvious source of sugar. Less obvious is the nectar contained in honeybee abdomens. Wasps will attack and dismember honeybees and carry off their abdomens from which they then suck out any nectar contained within the crop.
There are three ‘levels’ of sweet feeding wasp attack that bee hives may experience.
Scouting attacks are a daily occurrence at bee hives during the sweet feeding season and this level of wasp attack should not be feared as it can generally be managed through good wasp proofing techniques. Scouting attacks continually probe and challenge bee hives looking for weaknesses. If a weakness is found then scouting attacks can rapidly progress to more critical forms of wasp attack. In scouting attacks the honeybees are able to rebuff scouting wasps and prevent them from gaining entry to the bee hive.
If wasp populations are especially high then even healthy and well defended bee hives may find it difficult to protect themselves from remorseless probing scouting attacks. Respite can be given to such hives by deploying WaspBane traps as described in the static trapping section. Interestingly bee hives represent a ‘hard’ food target as wasps are challenged by defending honeybees. Wasps will take the path of least resistance which means they will prefer to enter WaspBane traps rather than attack the bee hive provided that the trap is sited in the correct place.
Swarm feeding occurs when scouting wasps gain entry to the bee hive and gain access to honey stores. These scouting wasps then return to their nests and bring back their colleagues. Within a short space of time the bee hive can be confronted by hundreds if not thousands of swarm feeding wasps making it difficult for honeybee defenders to cope with the onslaught.
In swarm feeding, wasps find their way to the bee hive by landmark navigation, i.e. they receive precise co-ordinates and fly exactly to those co-ordinates. This means that interruption techniques can be used to overcome the challenge of swarm feeding wasps as described in the dynamic trapping section.
It is critical that beekeepers do not accidentally create swarm feeding conditions on other food sources in the vicinity of their bee hives. Honey spills, fruit litter or low efficiency traps are such examples of ‘soft’ food targets. Wasps will take the path of least resistance and ‘soft’ food targets represent an easy boon for them. However, such food sources invariably become exhausted. The spilled honey or fruit litter is fully consumed. Low efficiency traps become full or dry out. Once these ‘soft’ food sources expire the swarm feeding wasps will need to find an alternative and this is likely to be the bee hives in proximity to the ‘soft’ food source. The problem however is that these swarm feeding wasps will no longer be solitary scouting wasps but will instead be massed ranks of wasps making it far more challenging for the honeybees to defend their nests.
The danger with swarm feeding is that it can reach a tipping point where it becomes frenzied feeding.
Frenzied feeding is characterised by the production of large amounts of pheromone which sends both wasps and honeybees into frenzied fighting. Once this stage is reached then it becomes very difficult (but not impossible) to save the hive. In frenzied feeding wasps no longer navigate to the bee hive by navigational map. Instead they are draw by the smell of distress/alarm pheromone and so are draw by a scent trail. This makes dynamic trapping much more difficult and additional measures have to be taken to protect the hive.
Techniques on static and dynamic trapping are given in later sections. It is important to understand that sweet feeding wasps are worker wasps that have already contributed ecologically and are by definition in decline and starting to starve to death. Trapping these sweet feeding nuisance wasps has no impact on future wasp generations as queen wasps and drones are largely unaffected by WaspBane.