Bark jumping spider
Marpissa muscosa
The bark jumping spider is a distinctive, flat-bodied jumping spider with grey-brown camouflage coloration. It reaches significant body lengths for a jumping spider and prefers sun-exposed tree trunks or wooden fences. The species is known for its excellent vision and active hunting behavior during the day.
Details
Identification
Large anterior median eyes, flattened body, grey-brown hair with dark chevron patterns on the abdomen.
Social behavior
Solitary, but shows some tolerance towards conspecifics in shared overwintering retreats under bark during winter.
Diet
All kinds of insects, often larger than the spider itself, as well as other spiders.
Hunting strategy
Active visual hunting; prey is stalked and overwhelmed with a precise jump, often secured by a dragline.
Spawning substrate
Under loose bark, in wall crevices, or under dead wood.
Overwintering
Overwintering as adults or sub-adults in sturdy silken sacs under loose bark.
Ecology
Ecological role
Important predator of small insects in wooded habitats and on wooden structures.
Natural predators
Birds, spider wasps (Pompilidae), larger predatory spiders.
Competitor species
Other bark-dwelling spiders such as the walnut orb-weaver spider (Nuctenea umbratica).
Ecosystem service
Natural pest control through predation of insects.
Threats
Loss of old-growth trees, removal of loose bark in forests, and renovation of old wooden fences.
Scientific profile
Profile
Distinguishing features
Largest native jumping spider species (genus Marpissa). The body is significantly flattened. Characteristic is the dark, often interrupted 'W' pattern on the opisthosoma. The frontal eyes are very large and highly functional.
Habitat
Prefers sun-exposed trunks of old trees (pine, oak), dead wood, wooden fences, and occasionally on sunny house walls near forests.
Role in food web
Important predator in the tree bark ecosystem; regulates insect populations and serves as food for birds and specialized spider wasps.
Protection & threats
Main threats
Intensive forestry (removal of old-growth and dead wood), loss of structurally diverse forest edges, and the sealing of near-natural areas.
Population trend
Stable; the species is considered widespread and not threatened in Germany and large parts of Central Europe (Red List Germany: Least Concern).