A brief life history of the Wasp Spider (Argiope bruennichi)

A female Wasp Spider

The Wasp Spider (Argiope bruennichi), is a striking, large 'orb-weaver' found across Greece and Europe. Females have bold yellow, black, and white stripes, while males are smaller and less colourful.

A Wasp Spider egg sac

At the end of the previous summer, a female Wasp Spider spun several, silk-wrapped, egg sacs containing hundreds of eggs before her life ended in the autumn. The egg sacs are very tough and weatherproof, to ensure the protection of the eggs during the winter months.

In the spring, the baby spiders or 'spiderlings' hatch out inside the egg sac. They remain clustered inside it for a short while before dispersing by a process called 'ballooning', this involves the spiderlings releasing silken threads that catch the wind and carry them away from the egg sac and out across the surrounding area. Unfortunately, most of the spiderlings will perish during the ballooning but a few will settle in meadows, grasslands, or gardens, where they begin life as small, vulnerable orb-weavers.

Through successive moults during the summer months, the female Wasp Spiders grow rapidly in size and their bold yellow, black, and white bands soon appear, making them among the most striking spiders in Corfu.

A juvenile Wasp Spider and 'stabilimentum'

They build large orb webs with an obvious characteristic zigzag web pattern called a 'stabilimentum' within the web. This silk structure is also found in the webs of some other species of orb-web spider and its function is a subject of debate, thought to stabilise the web and aid in camouflage or prey attraction. Juvenile Wasp Spiders sometimes produce a tight stabilimentum at the centre of the web in which they patiently wait for their prey of grasshoppers, crickets, and bees which are quickly wrapped in silk and subdued with spider venom.

Males mature earlier in the season, remaining far smaller and paler than the females. Their entire adult lives are focused on finding a mate, which is a dangerous undertaking in the world of spider romance. A male approaching a female’s web risks being mistaken for prey so, to increase his chances, he often attempts mating when she is distracted while feeding on other prey.

A male Wasp Spider

Mating itself is dramatic. Each male has two copulatory organs called "pedipalps" which are used to transfer sperm to the female. During copulation, one pedipalp often becomes lodged inside the female’s genital opening and breaks off, it acts as a “mating plug,” reducing the chance that another male can inseminate her again. This is a costly sacrifice for the male spider as, with only one pedipalp remaining, any attempt at a second mating will usually mean that he does not survive. In many cases, the female kills and eats the male which gives her extra energy for her future egg production.

After mating, the female continues to feed and grow until, in late summer, she produces her own egg sacs, repeating the annual cycle. As autumn advances, her vitality wanes, and by winter she dies, leaving behind only the silken cases of eggs that will create the next generation.

A female Wasp Spider feeding on a bush-cricket

The life of the Wasp Spider (Argiope bruennichi) follows a very precise rhythm, starting with eggs that spend the winter in a silk egg sac; then the spiderlings hatching out and dispersing by 'ballooning' on the wind; surviving juveniles growing through summer with males risking all for a single mating, before the females ensure continuity before fading away with the seasons.