Dark comb-footed spiderling

Description:

Steatoda grossa is a common species of spider in the genus Steatoda. As one of this spider's common name indicates, the spider superficially resembles, and is frequently confused for, the black widow and other venomous spiders in the genus Latrodectus. It is a cosmopolitan species found in many parts of the world, including North America, Australasia, and Europe. Like black widows, the female S. grossa is 6-10.5 mm in length, and dark colored, with a round, bulbous abdomen. Typical coloration ranges from purplish-brown to black, with light-colored markings. Unlike black widows, redbacks, and other Latrodectus species, the S. grossa does not have a bright red hourglass pattern or any other bright markings. Like many spiders, the male is sometimes smaller; But can many times be nearly as long as the females. It measures 4.1-10.0mm in length, and is thinner than the female. The two sexes are colored similarly, however the sexually mature male almost always has lighter, more reddish coloured legs than the female. The S. grossa sheds up to six instars before reaching full growth. They can go several months without feeding, provided they have access to water. A well fed female can lay 3 or more egg sacs each year, in which each egg sac typically contains between 40 - 100 eggs. The mother can often be observed watching her eggs for hours, even days at a time once the eggs start changing color and grow close to hatching. At normal household temp/humidity, and egg will usually hatch within a month of being laid. The spiderlings are independent from time of hatch. Female S. grossa spiders can live up to six years; the typical lifespan for the male is 1-1.5 years. Males often die shortly after mating.

Habitat:

Behind our barn.

Notes:

Tiny spider - about 1.5mm body (see last photo for size comparison)