Theridula emertoni is a species of tangle web spider

Theridiidae

Theridiidae is a large family of spiders, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders. The diverse family includes over 2200 species in over 100 genera) of three-dimensional space-web-builders found throughout the world...

 commonly found in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

. Prior to its formal description in 1954, specimens of T. emertoni were often classified as T. opelenta, a species with whom its range overlaps. The species can be reliably distinguished from T. opulenta by the epigyne

Epigyne

The epigyne or epigynum is the external genital structure of female spiders. As the epigyne varies greatly in form in different species, even in closely related ones, it often provides the most distinctive characteristic for recognizing species...

 in females or by the pedipalp

Pedipalp

Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...

in males.

Adult females are between 1.7 and 2.8 mm in length. Adult males are between 1.6 and 2.3 mm in length.

External links

• Theridula emertoni at Bugguide.net