Well, what you’re seeing is the aftermath of the end of a colony, up to now these worker wasps have been busy building their nest, tending to the larvae inside and catching insects. This has all changed because that nest has pretty much ceased to function. 

 

When the Queen wasp is alive and producing eggs, the workers are really busy and under the control of the pheromone given off by the Queen; when we destroy a nest and take it away immediately, you can see the instant affect this has on the workers as they become confused and disorientated. 

Equally, when that Queen dies from natural causes the same thing happens. 

 

Up to now, the workers have been bringing insects for the larvae who release a sugary secretion that in-turn, they feed to the wasps, sort of as a thank you for looking after us. When the production of larvae stops, there is no more food for the wasps which will now starve to death. 

 

The alternative food source for these hungry wasps are sweet liquids such as the sap from willow trees and lime trees; anyone who parks their car under one of these trees understands how much sap gets deposited and wasps will crawl over surfaces, desperately sucking up any food they can. 

 

Likewise, juices from fallen fruit can be sucked up and the natural alcohol found as a result of fermentation can make wasps aggressive. If you are seeing wasps wandering around aimlessly, then you have a collapsed colony and there is not much that you can do about it. 

 

In general, the wasps don’t have a nest to defend so they are much less likely to attack you, although they will still sting if they land in your hair or get trapped in clothing. One possible solution is to install lures around the garden, these attract the wasps into a chamber where they drown in the liquid lure. These lures will also bring more wasps and even hornets into the area so they should be used away from where you spend any time.