The Wasp Spider Argiope bruennichi is a fairly recent addition to the fauna of England, migrating from continental Europe. It was first recorded here in 1922 and has been steadily increasing ever since. It is now reasonably common across much of south England.
The female (body length of about 2cm) is far more noticeable than the much smaller and dull coloured male. Like a lot of male spiders he leads a rather difficult romantic life. He must wait on the edge of the females web until her final moult into the mature form. Then her jaws are soft and it is the safest time for the male to move in and try to mate with her. Even then he risks being eaten and indeed many males end their short lives in this way – who said love was easy!
The female spins a web quite low down in the tall grasses of meadows which are not cut or are cut fairly infrequently. The Wasp Spider relies on tall over-wintering vegetation for the safety of her egg sac, which she makes in amongst the grasses. In the web is what is known as a ‘stabilimentum’, a zig-zag pattern. The function of this structure is unclear and theories are varied – e.g. stablizes the web, attracts prey, deters birds from flying into the web.
In the photo above the stabilimentum is clearly visible. The Wasp Spider is of course trying to catch prey in the web, their favourite food are Grasshoppers and Crickets. It may be that the Wasp Spiders population rise and spread have been aided by the parallel spreading of Orthoptera species in recent years, e.g. Roesel’s Bush Cricket and Long-winged Conehead.
The photo above shows the egg sac. These can be found usually quite close to the mature females on their webs, amongst fairly dense tall grasses. They resemble a small urn, are wrapped in a protective silk net, with a sealed lid – a fascinating construction of delicate beauty!
Finally, here is the business end of a female Wasp Spider, not what you want to see if you are a Grasshopper! The spinner glands at the rear of her abdomen fire out fine silk strands. In a matter of seconds the victims are wrapped up and ready to be devoured!