Cryptachaea porteri

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Current valid name

Cryptachaea porteri (Banks) (family Theridiidae)

Recognition and diagnostic features

Small, dark brown with globose abdomen with small peak on dorsoposterior surface.

Related or similar species

Theridion melanurum


Body lengths when mature: male: 1.6 - 2.8 mm, female: 2.2 - 4.9 mm

Immatures resemble miniature adults.

Egg sac

Description: spherical sac of yellowish silk, suspended in web, 2.99 ± 0.36 mm diameter

Number of eggs per sac: 30.8 ± 14.5

Size of egg: 0.60 ± 0.024 mm

Time of year eggs are likely to be laid: September-October


In California: Fresno, Riverside, Tulare counties

Elsewhere: eastern United States, south to Panama, West Indies

Native to North America

This species probably has been transported and become established outside of its range because it was not known from California until recently.


Small cobweb-weaving spider. Makes webs in grape leaves, found in grape bunches. Female guards egg sac.

Status in table grapes

Level of Incidence: common

Level of Concern in New Zealand: WPNZ (May 2010) nr, BORIC (Dec 2011) nr (not listed), MAF-BPRA (2002) nr (coding definition)

Level of Concern in Australia: WPAU (2006) nr (coding definition)

Level of Medical importance: none

Common name

None for species, combfoot spiders for family

Taxonomic history

In 2008, it was transferred from the genus Achaearanea to Cryptachaea.

Commonly encountered synonyms

Achaearanea porteri

Selected references

Levi, H. W. 1955. The spider genera Coressa and Achaearanea in America north of Mexico (Araneae, Theridiidae). Amer. Mus. Novitates 1718, 33pp.

Yoshida, H. 2008. A revision of the genus Achaearanea (Araneae: Theridiidae). Acta Arachnologica 57: 37-40.