Crab spiders

Family Thomisidae

Thomisus spectabilis with a bee

Crab spiders are no active hunters. They make more use of the camouflage techniques than other spiders and catch their prey with their front legs. The color of the spider is adapted to the hunting terrain they use and is mostly extravagant. They remain unmoved until the prey arrives and catches it. With a poisonous bite (not dangerous to humans) they kill their prey and suck it dry. They can be found on flowers or leaves of plants. Often the crab spider remains for days, even weeks at the same spot. The front two legs, that are often larger and stronger than the other six, are held sideways, ready to catch the prey immediately. Because they sit on easily spotted places they are also easy to catch by the predators. When they spot a possible enemy they move quickly at the other site of the flower or leave. Their eyesight is excellent developed as can be seen on the pictures. They have normally two big front eyes.

Crab spiders are easy recognizable if you tease them. They widen their legs and move side ways like a crab. Their size is between 4 - 10 mm.

The females usually stand guard with their egg sacs. The egg sacs are fastened to the vegetation and are usually flat.

Genus Diaea or flower spider

This spider hides between vegetation, especially in or nearby a flower. Their color is well adapted to its surrounding. Their size is between 5 and 7 mm.

Diaea evanida
Diaea evanida

Diaea ZZ151	Diaea ZZ152

Diaea ZZ402	Diaea ZZ402

Diaea ZZ400 pilula?	Diaea ZZ400 pilula?

Diaea? ZZ149	Diaea? ZZ150

Diaea? ZZ446 WA by Wendy Eiby

Genus Poecilothomisus

This is the sole member of this genus.

The attractive spider has a remarkable apprearance with her orange body, the seven dots on her abdomen and the shiny white legs.

It occurs in NT and QLD. The female has a length of 10 -12 mm.
It is usually found amongst trees along creek banks.

Poecilothomisus speciosus NT by Marrissa Howard & Ben McCoy

Genus Runcinia

Runcinia acuminata is the only member of this genus in Australia. The name Runcinia elongata is not used anymore. The long oval abdomen has long stripes at the side. Eyes are small. They occur Australia-wide. The female reach a length of 10 mm and the males 6 mm. Females guard their egg-sacs they camouflages with fragments of grass flowers and seed-heads. Spiders are found on bushes, flowers and in seeding heads of grasses. Here she is found on the orchid Thelymitra adorata. The orchid is a terrestrial orchid growing near wetland edges with melaleuca and eucalypt. It is critically endangered with fewer than 100 plants located this past flowering season (2011).

Runcinia acuminata on orchid Thelymitra adorata by Boris Branwhite, Wyong terrestrial orchid research, NSW

Genus Stephanopis

Stephanopis barbipes male

barbipes means bearded	Stephanopis barbipes female. The female resembles Sidymella lobata

Stephanopis barbipes male	Stephanopis altifrons

Stephanopis corticalis?	Stephanopis pustulosa
	Stephanopsis can be recognized because it is adorned with spines and tubercles resembling the rough bark on which it lives. Stephanopis pictures by Robert Whyte

Genus Sidymella

A genus with eight described species distributed all over Australia. They can be recognized by their trangular shaped abdomen. Their size is aproximately 7 mm. These crab spiders can be found on flowers and foliage where they are good camouglaged by their colouring, ranging between brown, orange and yellow.

Sidymella ZZ144 (Vic) by Michael Barritt	Sidymella ZZ144 (Vic) by Michael Barritt

Sidymella trapezia (Vic)	Sidymella trapezia (Vic)

Sidymella hirsuta (= hairy) by John Mansfield NSW	Sidymella hirsuta by John Mansfield NSW

Genus Tharpyna

The seven described spider in this genus live on and under bark of trees. The spiders are dark brown to black with white or yellow spots and other markings. The spiders are nocturnal. Their size is 5 - 12 mm

Tharpyna campestrata male WA	Tharpyna campestrata female WA

Genus Tmarus

Nine species are present in Australia. Their color is gray/brown and the are well camouflaged because they can be found along the margins of dead and living leaves or dead twigs. They build small retreats by folding the tip of leaves or grasses. Tmarus can be found hanging at the end of a single snare.


Tmarus species detail of the cephalothorax.	Tmarus species with a prey (by Jurgen Otto)

Genus Thomisus

This is the only species known in this genus in Australia. Its name is Thomisus spectabilis.
As can been seen on the picture below they even catch bees. The spider seizes the bee by its front legs and bites it in the neck. The spider keeps its hold on the bee till the bee gives up its resistance.


Thomisus spectabilis
	Thomisus spectabilis male and yellow form (by Robert Whyte)
Thomisus spectabilis white faced

Thomisus spectabilis brown faced

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Ed Nieuwenhuys, 20 October 2011
26 February 2011, 24 January 2010, January 4, 2009 Ronald Loggen, 5 December 2005