The Humped Crab Spider

The humped crab spider does not build a web but hunts insects by waiting in ambush on a flower for an unsuspecting fly or bee to land within its grasp. When its prey is close enough it uses its pair of enlarged front legs to hod it and then bites the back of its neck to kill it.

This species is common in the Maltese islands. It is widely distributed and it can be found throughout most of Europe, except for the northern parts and in Africa as far as South Africa. Its range extends east as far as Siberia and Central Java.

Spiders of this species can be yellow, pink, or white depending on the colour of the flower on which they hunt. This is advantageous as it camouflages the spider against its background making it more difficult for unsuspecting prey to notice it.

In Maltese, the humped crab spider is known as brimba tal-fjuri mħattba.

Crab spiders got their name from their habit of moving sideways like crabs and possibly also because of their enlarged front legs which resemble a crab’s claws.

The specimens one is likely to notice on flowers are females. Males are much smaller and inconspicuous which is of survival value.

In most species of spider the male has to take precautions to ensure that he is not eaten before managing to copulate. This is often done by presenting her with an insect which she would eat while he is approaching her.

The male humped crab spider is so small that the female totally ignores him and allows him to climb on her back without devouring him.

The humped crab spider is one of several species crab spider belonging to the Thomisidae family. The name crab spiders is also used for several other species of spiders from other families.

In the Maltese islands one is also likely to meet another species of crab spider which is known in Maltese as brimba tal-fjuri. This species can also have different colours but is not humped and has a black design on its back.  

This article was published in The Times of Malta on 24 July 2014.