A typical spider wasp.

Spider wasps

Spider wasps are large, restless wasps that prey on spiders to provide food for their larvae.

• 1 November 2008 | Updated 14 October 2011

• Description
• Food sources
• Life history

Description

Large black and orange spider wasps are a common sight in Australian backyards during summer.

Spider wasps range in size from a few millimetres to around 3.5cm and all are found in the Order Hymenoptera (which also includes ants and bees), Family Pompilidae.

They may be all black, all blue, or black with orange, grey or white parts.

They are found all over mainland Australia and Tasmania, in all habitats including suburban gardens.

Female spider wasps look dangerous and do have a powerful, sting but they are not aggressive towards people and can be safely ignored.

Food sources

Spider wasps attack spiders which are often bigger than they are and can be seen dragging them along the ground.

With their long legs, rapidly flicking wings and restless jerky motion, they prowl the garden searching under leaves and bark for huntsmen and wolf spiders. When they find one, they paralyse it to use as food for their larva.

Unlike the parasitic larva, adult wasps are nectar feeders.

Life history

Spider wasps are solitary and don’t build up large numbers. They nest alone, generally in a burrow in the ground – not in a colony like other wasps and ants and bees.

The female catches spiders of various kinds as food for her larvae. She stings the spider to paralyse it and then usually drags it into her burrow where she lays an egg on it. When the larva hatches, it starts to eat the still living spider. When mature, the larva pupates to emerge as an adult the next summer.