Family: Uloboridae
Species: Zosis geniculatus

♀5mm

WOODWORK FACTORY 22-11-2014 SAT 9:07AM

Zosis geniculatus is a common house spider.

 It creates a ragged blue grey circular web, with star shaped egg sacs.

Insects trapped in the web are rolled with the hind legs and wrapped in silk. The bundle is eventually carried to the hub of the web and sucked dry.

The hub is lace-like and occasionally is traversed by a closely woven band of silk. Suspended in the web are egg-sacs which are pinkish and have characteristic horn-like projections. Insects trapped in the web are rolled with the hind legs and wrapped in silk. The bundle is eventually carried to the hub of the web and sucked dry.

diagram showing spines on leg

The upper margin of the second last segment (metatarsus) of the fourth leg is armed with a row of strongly curved spines known collectively as the "calamistrum" (arrowed in diagram, right). It is through the combined action of the cribellum and calamistrum that the bluish silk characteristic of the Uloborids is produced. The front legs of the Uloborids are extraodinarily long, often longer than the entire length of the body. Unlike other spiders, Uloborids do not possess venom glands.

Spiders of the Family Uloborids  have a cribellum on the underside of the abdomen, in front of the spinnerets.

cribellum, plural cribella, adjective cribellate - a spinning organ having many fine pores, situated in front of the spinnerets in some (cribellate) spiders.  Not all spider groups has this organ.

The spider normally sit on top of the web. But when disturbed it will skip over to the other side of the web

Top : Egg sac henging on the iop of the web.

Below :  The mother spider rest at the centre of the web.

 

The wen is build in a dark obscure part of a store room.

The mother spider guarding her egg sac.

Near by the same corner another species mother Smeringopus pallidus with a school of spidering handing upside down their web.