Bluebottle

On a hot day recently, it was the Saturday before last, I stooped down near where I park my van to see if the basil seed I had tossed in the adjacent garden was germinating. I was disappointed that I could see but one tiny seedling, but not surprised as I had not worked up the ground properly, had not watered nor put out snail protection.

I saw a cricket come out of a small hole and scurry along. It was followed by a bluebottle 'ant' which was in pursuit and quickly caught up whereupon it grappled the cricket bending its abdomen to sting. The bluebottle was a grand specimen appearing to be over 25mm in length yet shorter and finer than the bulky cricket, which broke free and took off only to be quickly overhauled and stung repeatedly by the thrusting abdomen. Soon the cricket was inert and the bluebottle dragged it with considerable exertion and manoeuvring around snags back to the hole and underground.

I knew that bluebottles are not ants but wingless female wasps, the male being smaller, winged and of different colouring, and that some wasps, particularly solitary wasps, capture other insects and bury them paralyzed by sting, laying their eggs on them so their hatching larvae have a ready food supply. I have watched 'spider killer' wasps catching spiders, and come across wasp nests containing multiple spiders.

I concluded that the bluebottle was doing this with the cricket. Tonight, before writing up this observation, I search engined bluebottles to find that this particular wasp is Diamma bicolor, the only wasp of the sub family Diamminae, and it hunts and feeds exclusively on mole crickets. How about that?

I can imagine that a bluebottle sting would be painful to humans. Apparently there is a danger of severe allergic reaction (anaphylaxis) in a small percentage of people, as there is with ants and bees. A friend of mine is allergic to jumping jack ants and has to carry medication to keep her conscious if she is stung, giving her a small amount of time to get to doctor or hospital for life saving injection. I knew a commercial beekeeper who had no problem with bee stings but a wasp sting was life threatening.