Tiny, but able to attack prey up to three times its size this brightly coloured flower crab spider (Thomisus genus) waits on a nasturtium flower in our vegetable garden for potential victims.

Cryptically coloured, these tiny spiders are able to change their colour. The colour change takes up to two days and they can change from white to yellow or pink depending on the flower they are sitting on.

The crab spiders get their name from their sideways gait. They catch approaching insects using their relatively long first and second pairs of legs. Once a victim is caught, the spider kills it with a bite behind the head, injecting an enzyme that dissolves the victim’s insides so it can be sucked dry. Once done, the spider drops the empty but still intact exoskeleton of its prey.

Happily for the vegetable gardener, their food sources include aphids, red spider mites and thrips. As they are so tiny, these spiders can be dispersed on the wind. The brown male is even tinier than the yellow female in the photograph.

Thanks to Joan Young’s photo here, that enabled me to identify this spider.

Posted by Carol at letting nature back in

Sources: Biodiversity explorer http://www.biodiversityexplorer.org/thomisus.htm; South African  Agricultural Research Council http://www.arc.agric.za/ Thomisidae-General-Information.aspx

Weekly photo challenge WPC: Tiny