Crab spider, araña cangrejo

Crab spider hidden in a Clover flower (Trifolium pratense).

This species shows an extreme sexual dimorphism both in size and coloration. The adult males reach a body length of only 2–4 millimetres, while females are 7–10 millimetres long. This species is characterized by the prominent rear corners of the opisthosoma.

In males the basic colour of the prosoma varies from yellow brown to dark brown, the opisthosoma may be yellow and green or brown. Also females are very variable in colour, their basic colour can be white, yellow or pink.

As a matter of fact these crab-spiders hide themselves adapting the colour of their body to the colour of the flowers on which they are waiting for preys, a behaviour that conceal them from predators and from the pollinating preys.

These crab spiders do not make a web, but actively pursue their preys. They usually wait for preys positioned for hunting on flowers. Their victims are disguised by assuming the same colour as the flower, fooling both insect and bird predators.