Black Tail Crab Spider (Synema parvulum)
Detailing the identifying qualities of the Black Tail Crab Spider, including physical features and territorial reach.
Updated: 2/8/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
Though the Black Tail Crab Spider lacks giant claws, it makes up for it with mighty jaws and a great work ethic.
Crab spiders have longer front legs that sit more forward on the body than typical spiders. Their back pairs of legs are so much shorter and further back than the front pairs that it gives them the appearance of a crab. This particular species is very tiny and reddish-brown. The abdomen is wide and round but also flat on top. The bottom has a black crescent-shaped black mark at the end of the abdomen, as if its rear end was dipped in black ink.
Crab spiders do not use a web to catch prey. They ambush insects, lying in wait inside or on flowers. Because this spider preys on insects that may damage plants and flowers (like aphids and certain beetles), it is considered helpful to the garden ecosystem. They have also been found on piled wood and tree bark. The Black Tail Crab Spider will grab its insect prey, using its long and strong front legs to help pin the victim down. It then bites the prey with its strong jaws, immobilizing it with venom for later consumption. The Black Tail Crab Spider is not known to bite humans,however, and it takes little interest in our activity. Their venom is not poisonous.