Cheiracanthium punctorium

Cheiracanthium punctorium, one of several species commonly known as the yellow sac spider, is a spider found from central Europe to Central Asia. They reach a length of about 15 mm, and their bite can penetrate human skin; the bite has been compared to a wasp sting, perhaps a bit more severe, although susceptible persons can have stronger reactions, like nausea.^[1] Females build an egg sac of about 4 cm in high grass. It opens below and is aggressively defended.

A Cheiracanthium punctorium in Germany

Egg sacs in Germany

Cheiracanthium punctorium
Female Cheiracanthium punctorium with drops of venom on its fangs
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Family:	Cheiracanthiidae
Genus:	Cheiracanthium
Species:	C. punctorium
Binomial name
Cheiracanthium punctorium (Villers, 1789)
Synonyms
Aranea punctoria Aranea nutrix Clubiona nutrix Cheiracanthium nutrix Drassus maxillosus Anyphaena nutrix Cheiracanthium italicum

In Germany it is the only "seriously" venomous spider, but is a rare species, occurring chiefly in the southern half. Notable numbers are found in the Kaiserstuhl region, the hottest part of the country. There is evidence that the species is spreading in northeastern Germany, e.g. Brandenburg. The main reason is an increase in fallow, uncultivated land in these areas, though changing weather patterns leading to increased aridity and less precipitation may also play a role. C. punctorium is most numerous in the steppes of Central Asia.

The genus Cheiracanthium was transferred from the Clubionidae to the Miturgidae,^[2] and then to the Cheiracanthiidae.^[3]