Family Araneidae

Genus Argiope

Species bruennichi

Wasp spider

Argiope bruennichi female

The common name of this beautiful spider is wasp spider. This spider is, like all orb-weavers, not poisonous for us.
The adult female has a shining silvery cephalothorax (head) and a yellowish abdomen with black and white bars across it.

Argiope bruennichi met cocon (foto van Iljitsj van Kessel)

Argiope bruennichi female

The adult female is much larger than the male. The male measures between 4 and 6 mm while the female has a full grown size between 14 - 17 mm.
When the female is loaded with eggs she can become enormous in size.
Argiopes can be easily identified by the zigzag of white silk in their webs. Like all orb-weavers, they have ringed legs.
The function of the zigzag of white silk in their web is not clear. There are several ideas what the purpose may be.
It may be used to attract insects because it is radiating UV-light and that attract insects. Another explanation is that it is to frighten predators. The spider shakes the web vigorously when something large is approaching and that result in a blurry white spot.
Another explanation can be that the spider makes the web clear to see and that should avoid large animals to destroy the web.

Youngsters just hatched from their papery cocoon.

The just hatched spiders are very small but already have all the features as the adult spiders. The picture was taken from a spider walking over a news paper.

The zigzag is not in the web when the spiders are young. In the pictures below you can see that the young spider sits in a circular zigzagging construction. When it gets older it makes both forms and eventually the spider only makes the zigzag in a line.

In July the males mate with the females and often loose their life or some legs after their 'duty'.
The female makes a brown cocoon one month after mating and the young spiders hatch the next year in spring. The female dies in the winter.

Argiope bruennichi female
Young female (left) and young male (right).

When the spiders are young the differences between the sexes is not so obvious.
But the sexes can be identified by the form of the palps.
Like all spiders, the palps of the male are bulbier than the palps of the female.

Argiope bruennichi female Argiope bruennichi male
Palps of the female (left) and male (right) spider.

The spider lives in open grassy areas and makes her web amongst the grass and low herbage. In the Mediterranean she is very common but the last decennia she is moving up North.
She is reported often from Limburg in the South of The Netherlands, around Berlin in Germany and in Great-Britain where she was already reported in 1940.

When the spider catches her prey she wraps it very fast in silk. After a lethal bite with venom and protein dissolving enzymes she waits until the prey does not struggle anymore and sucks it empty or hangs the packet in her web to consume it later.
If a too large insect gets into her web she bites the threads in which the insect hangs loose of her web until the insect falls out.

Jummie, wrapped grasshopper as desert!

Ed Nieuwenhuys, September 2 2008,
September 13, 2003