Ballus chalybeius

Ballus chalybeius is a jumping spider. It is the type species of the genus Ballus.

Oak Jumping Spider
female
Adult male
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Family:	Salticidae
Subfamily:	Salticinae
Genus:	Ballus
Species:	B. chalybeius
Binomial name
Ballus chalybeius (Walckenaer, 1802)
Synonyms
Aranea depressa Aranea chalybeia Attus chalybeius Salticus annulipes Attus annulipes Salticus brevipes Salticus heterophthalmus Euophrys suralis Euophrys brevipes Marpissa brevipes Attus heterophthalmus Salticus obscurus Ballus heterophthalmus Attus brevipes Attus quinquefoveolatus Attus biimpressus Balla heterophthalma Dendryphantes annulipes Dendryphantes brevipes Attus seguipes Ballus depressus Ballus obscurus

Appearance

• 
  subadult male in retreat
• 
  Drawing of male (1868)

This flattened spider can reach a length of 3–4 millimetres (0.12–0.16 in). The prosoma is dark brown in females, with irregular lighter markings. The lightly yellow legs have dark rings in both sexes. In males, which are generally darker, the first legs are dark and thickened. The species is similar to Ballus rufipes, which is smaller and much darker.^[1]

Habits

During summer, the female builds a flat silken retreat on the underside of a leaf and guards its egg sac inside.^[1]

Habitat

It can be found mostly on the fringes of deciduous forests, on broad-leaved bushes and trees, particularly oaks, and in the grass. In Central Europe, they are widely distributed and in most areas quite common.^[1]

Distribution

Ballus chalybeius occurs in Europe, North Africa to Central Asia.^[2]

Name

The species name is derived from Ancient Greek chalyb- "steel".