Originally Posted by
Pigmy Pony
The adults also kill a lot of other insects, many of those being pest species, which they feed to the grubs, which in turn shit out sugars which the adults feed on. When all the grubs have become adults, the sugar source is then gone, and that's when the adults go foraging and become a real nuisance.
Then by the time colder weather returns, all the wasps die, but not before the queen gets knocked up and goes into hibernation. Then next spring it all starts again.
None of this detracts from the fact they are a right bunch of bastards.