Pyjama spider
Hypsosinga heri
The Pyjama spider is a small orb-weaver characterized by its distinctive pattern of light longitudinal stripes on a dark, shiny background. It prefers sunny, moist habitats such as reed beds, sedge marshes, and silting zones of water bodies. The species is widely distributed in Central Europe but has become rare in many places due to disappearing habitats.
Details
Identification
Three yellowish-white longitudinal stripes on the dark abdomen; shiny cephalothorax; legs yellowish to reddish-brown.
Social behavior
Predominantly solitary; webs are often built in close proximity to each other in suitable vegetation.
Diet
Feeds on small flying insects such as midges, aphids, and small flies.
Hunting strategy
Construction of small, vertical orb webs in the herb layer, usually just above the water level or the ground.
Overwintering
Overwintering usually occurs as a juvenile or subadult in leaf litter or within hollow plant stems.
Ecology
Ecological role
Important predator of small insects in riparian zones; serves as prey for birds, dragonflies, and amphibians.
Natural predators
Insectivorous birds (e.g., reed warblers), assassin bugs, ichneumon wasps, and larger spider species.
Competitor species
Other species of the genus Hypsosinga as well as small representatives of the genus Tetragnatha (long-jawed orb-weavers).
Ecosystem service
Natural pest control through the consumption of mosquitoes and other insects.
Threats
Loss of wetlands due to drainage, intensive shoreline use, reed harvesting, and climate change.
Scientific profile
Profile
Distinguishing features
Hypsosinga heri is a small orb-weaver. It is characterized by its striped abdomen and its strict association with reed beds. Compared to related species in the genus Hypsosinga, the pattern is often more high-contrast and the ecological niche more specific (hygrophilous).
Habitat
Highly specialized in moist to wet habitats, particularly reed beds (Phragmitetum), sedge marshes, and silting zones of standing or slow-moving water bodies.
Role in food web
Predator of small insects; serves as prey for birds (e.g., reed warblers) and predatory insects.
Protection & threats
Status not on standard scale
Main threats
Loss of wetlands, drainage measures, intensive mowing of reed beds, bank stabilization, and climate change (drying out of habitats).
Population trend
Declining in many regions of Central Europe due to habitat loss; often listed on Red Lists as 'vulnerable' or 'endangered' (e.g., Red List Germany: Category 3).