Seothyra
| Buckspoor spiders | |
|---|---|
 |
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| Symmetrical capture webs above a Seothyra female's burrow | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Arachnida |
| Order: | Araneae |
| Suborder: | Araneomorphae |
| Family: | Eresidae |
| Genus: |
Seothyra Purcell, 1903 |
| Type species | |
|
Seothyra schreineri Purcell, 1903 |
|
| Species | |
|
See text. |
|
| Diversity | |
| 13 species | |
See text.
Seothyra, commonly known as the buck spoor spiders, buckspoor spiders or just spoor spiders, belong to a sand-dwelling, burrowing genus of araneomorph spiders in the family Eresidae. The 13 species are endemic to the arid, sandy flats and semistabilized red dunes of southern Africa. They are sexually dimorphic. The tiny males, which are seldom seen, imitate sugar ants or velvet ants in their appearance and habits, while the females hide in and hunt from their characteristic burrows. They are thermophilous, with males as well as females being most active on hot days.
They occur in Namibia, Botswana and South Africa. In South Africa they are present in northern Limpopo, and the Northern Cape as far south as the Tankwa Karoo. Their distribution is patchy, but when forming conspecific aggregations, their webs may even touch one another. Such clusters may contain thousands of females, with a density of 50 m−2, or locally, 100 to 200 m−2. Fossilized sheet webs which closely resemble the modern ones were found in Miocene eolianites of the southern Namib desert, and were dated to some 16 million years ago.
Like the burrowing Hermacha and Asemesthes genera, and dune-living huntsman spiders, they have long spinnerets with very long spigots, which the females use to bind the burrow walls with a succession of silk-rings. A Seothyra female expends 6% of her body mass on the first night of burrow construction, and considerably more before her web is functional. The burrow is straight or curved and as much as 15 cm (6 in) deep. When the burrow is dug, the sand particles are apparently bound in parcels of silk, to facilitate carrying, before these bundles are spun unto the surface webbing.
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Wikipedia