Slender crab spider
Tibellus oblongus
The slender crab spider, also known as the oblong running spider, is characterized by an extremely elongated, cylindrical body. Its coloration is typically straw-yellow to light brown with distinct dark longitudinal stripes, providing excellent camouflage on grass blades. Unlike true crab spiders, it belongs to the family of running spiders (Philodromidae). It does not construct webs but relies on its camouflage and speed for hunting.
Details
Identification
Extremely elongated opisthosoma (abdomen); light base color with a dark central stripe and often two fine lateral stripes; eye arrangement in two rows (4-4); legs pressed closely against the grass blade in resting position.
Social behavior
Solitary; exhibits territorial behavior and cannibalism towards smaller conspecifics.
Diet
Feeds on various flying insects, aphids, and other small arthropods living on grasses.
Hunting strategy
Ambush predator; the spider sits motionlessly stretched out on blades and attacks prey that comes within reach with lightning speed.
Spawning substrate
Egg sac is attached to grass blades or leaves and guarded by the female.
Overwintering
Overwinters as subadult or adult in leaf litter or under bark.
Ecology
Ecological role
Important predator of insects in grassland ecosystems; contributes to biological pest control.
Natural predators
Birds, lizards, spider wasps (Pompilidae), and larger predatory arthropods.
Competitor species
Other Philodromidae species and true crab spiders (Thomisidae) in the same habitat.
Ecosystem service
Regulation of insect populations in meadows and fields.
Threats
Intensive agriculture, frequent mowing of meadows, and loss of semi-natural grassland habitats.
Scientific profile
Profile
Distinguishing features
Strongly elongated, slender body (opisthosoma about three times as long as wide). Characteristic are two small black spots in the posterior third of the abdomen (often absent in similar species). Legs II are significantly longer than legs I.
Habitat
Open, sunny locations with tall vegetation, particularly semi-dry grasslands, dunes, wet meadows, bogs, and forest edges.