Reed orb-weaver
Larinioides cornutus
The reed orb-weaver is a medium-sized spider belonging to the Araneidae family, commonly found in moist habitats near water bodies. It is easily identified by the distinct folium pattern on its abdomen and its preference for riparian vegetation like reeds and tall grasses. The species constructs vertical orb webs to capture flying insects, often hiding in a silk retreat nearby during the day. Its coloration varies from light brown to nearly black, typically featuring a well-defined pale border around the abdominal pattern.
Details
Identification
Dark folium with a pale border on the abdomen; prosoma usually covered in light hairs; legs distinctly annulated with dark rings.
Social behavior
Solitary; exhibits territorial behavior when occupying optimal web-building sites within the vegetation.
Diet
Various flying insects, especially midges, caddisflies, and mayflies that emerge from the water.
Hunting strategy
Construction of vertical orb webs; the spider usually lurks in a retreat at the edge of the web that is open at the bottom.
Spawning substrate
Egg sacs are attached in sheltered corners of riparian vegetation or within rolled-up leaves.
Overwintering
Overwintering mostly as subadults or adults in sheltered silk retreats within hollow plant stems or under bark.
Ecology
Ecological role
Important regulator of insect populations in wetlands; facilitates the transfer of biomass from aquatic to terrestrial systems.
Natural predators
Insectivorous birds, ichneumon wasps (as hosts for larvae), spider wasps, and predatory flies.
Competitor species
Other orb-weaver spiders such as Larinioides sclopetarius (bridge spider) or Araneus diadematus.
Ecosystem service
Natural pest control by consuming large quantities of mosquitoes and other flying insects.
Threats
Loss of wetlands, intensive mowing of riparian vegetation, and the use of pesticides near water bodies.
Scientific profile
Profile
Distinguishing features
Characteristic is the sharply defined, dark folium on the abdomen. Unlike Larinioides sclopetarius, the pubescence is less silky and the habitat is more strictly tied to wetlands. The female epigyne possesses a long, narrow scapus. Males have elongated pedipalps with a specific bulbus structure.
Habitat
Strongly tied to wetlands: reed beds, sedge marshes, riparian zones of standing and flowing waters, wet meadows, and bogs.
Role in food web
Important predator in the ecotone between water and land. Regulates populations of flying insects and serves as prey for birds and specialized wasps.
Protection & threats
Main threats
Loss of wetlands due to drainage, intensive shoreline use, destruction of reed beds, and excessive mowing of riparian buffer strips.
Population trend
Stable; the species is widespread in Central Europe and often very common in suitable habitats (Source: Red List Center Germany).