Invisible Spider

Drapetisca socialis

"Drapetisca socialis" is a species of spider belonging to the family Linyphiidae. It is distributed across most of the Palearctic region.
Invisible Spider (Drapetisca socialis) "Now you see it. Now you still see it - just"!

D. socialis is a very small spider (upto 3mm) with a mottled body and striped legs that provide effective camouflage on the bark of a variety of trees, (predominently Beech) where, with close inspection, it can often be found seemingly resting on the tree surface.

This is however, highly deceptive. 

In fact, females construct a barely visible web, very finely threaded, covering an area of about 6 x 4 cm2, which lies almost flat against the tree surface. It is on this web, rather than the tree surface itself, where the spiders actually perch. It's also where females will wait to be approached by a suitable male for courtship to be initiated. 

Reasonably common and widespread, adults are most evident in the autumn, but like this individual, can be found right through to early January or even later, with some suspected of overwintering successfully.

 Drapetisca socialis,Geotagged,United Kingdom,Winter

Appearance

Even among the diminutive spiders in this family, this is a very small species with a body length of just 3 mm. It is usually found motionless on its delicate web, built on the trunk of a tree, where its mottled body and banded legs, allied to its tiny size, make it very difficult to see.

References:

Some text fragments are auto parsed from Wikipedia.

Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassArachnida
OrderAraneae
FamilyLinyphiidae
GenusDrapetisca
SpeciesD. socialis