What It Is and Where It Is Found
Stegodyphus sarasinorum is a social spider from the velvet-spider family Eresidae. It is found mainly in South Asia, including India and Sri Lanka.
Most spiders live alone, but this species is unusual because many individuals live together in large shared colonies.
They usually:
- build one large communal silk nest;
- create connected webs around the nest to catch insects;
- live together instead of defending separate individual territories.
The species is generally found in dry and semi-dry areas, scrublands and vegetation-rich habitats.
Why Its Social Behaviour Is Unusual
The most interesting feature of Stegodyphus sarasinorum is its cooperative lifestyle.
Members of a colony work together to:
- build and repair the web;
- catch and overpower insects;
- share food;
- protect young spiders;
- maintain the colony.
Working in groups allows them to capture prey that may be too large for a single spider to handle easily.
Several spiders may also feed on the same prey at the same time.
Female spiders show unusually high parental care. In some Stegodyphus species, the mother eventually provides her own body as food for her young. This behaviour is called matriphagy, meaning the young consume the mother after hatching.
Why Scientists Study It
This spider is important because permanent group living is very rare among spiders.
Scientists study it to understand how cooperation can evolve among animals. Colonies often consist of closely related spiders, which can make cooperation easier because helping relatives also helps shared genes survive.
However, living in close-knit colonies can create problems too:
- mating among relatives may reduce genetic diversity;
- disease can spread more easily;
- if one colony is damaged, many individuals may be affected at once;
- limited movement between colonies can make populations less adaptable.
Ecologically, the species helps control insect populations and forms part of local food webs.
