Cryptachaea

Archer, 1946

Species Guides

3

A of tangle-web spiders in the Theridiidae, established by Archer in 1946 and elevated from subgeneric status. Many were transferred from the revised genus Achaearanea in 2008. The genus contains over 100 species distributed primarily in the New World tropics and subtropics, with some species achieving or widespread distributions through human-mediated transport. Several species exhibit tendencies, occurring in and around human structures. Members of this genus are notable for ichneumonid in the Polysphincta group, which induce behavioral modifications in web architecture.

Cryptachaea blattea by (c) Steve Kerr, some rights reserved (CC BY), uploaded by Steve Kerr. Used under a CC-BY license.Cryptachaea blattea by (c) Grey Smith, some rights reserved (CC BY), uploaded by Grey Smith. Used under a CC-BY license.Cryptachaea blattea by (c) Steve Kerr, some rights reserved (CC BY), uploaded by Steve Kerr. Used under a CC-BY license.

Pronunciation

How to pronounce Cryptachaea: //ˌkrɪptəˈkiːə//

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Identification

Distinguished from related theridiid by genitalic ; transferred from Achaearanea in 2008 revision based on phylogenetic analysis. -level identification requires examination of male and female . Cryptachaea gigantipes and C. veruculata are closely related and may be confused; C. blattea is and widespread.

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Habitat

Natural in tropical and temperate regions; some occur in forest formations including Atlantic Forest remnants. Several species are , commonly found around houses and built structures. Cryptachaea gigantipes occurs in natural habitats in south-eastern Australia and has established in human-modified environments.

Distribution

Primarily a New World with many in South America. Cryptachaea blattea is ; C. veruculata occurs throughout the Palearctic and was introduced to Europe from New Zealand; C. gigantipes is native to south-eastern Australia and introduced to New Zealand (North Island, earliest records 2000); one species restricted to China. GBIF records indicate presence in Denmark, Norway, and Sweden.

Seasonality

In Brazilian Atlantic Forest, and subadult spiders have been observed parasitized between April and May, with rates correlating negatively with temperature and positively with precipitation. Spider abundance patterns appear related to forest formation type and seasonal microclimate variation.

Host Associations

  • Zatypota alborhombarta - Ichneumonidae (Pimplinae): induces behavioral modification in Cryptachaea jequirituba, causing construction of modified 'cocoon web' architecture
  • Zatypota riverai - Ichneumonidae: parasitizes Cryptachaea pacoti in Atlantic Forest of Ceará, Brazil; more frequent April-May, correlated with temperature and precipitation

Life Cycle

Development includes , spiderling, and stages. Observations in C. pacoti suggest only adult and subadult spiders are parasitized by , indicating possible selectivity for more developed stages.

Behavior

Web-building spiders constructing tangle webs. Parasitized individuals exhibit modified web architecture termed 'cocoon web'—characterized by fewer total threads, reduced proportion of sticky threads, increased reinforced thread ends, and greater leaf reinforcement—apparently providing structural stability and protection for developing larvae. Some show tendencies, occurring in human-modified environments.

Ecological Role

for ichneumonid in the Polysphincta group; parasitoid-host interactions influenced by including temperature and precipitation. In Atlantic Forest systems, may contribute to dynamics linking spiders and parasitoid .

Human Relevance

Some are and occur in domestic environments. Cryptachaea gigantipes and C. veruculata have been introduced to new regions (New Zealand, Europe) through human activity, with C. gigantipes showing evidence of limited initial introduction based on homogeneous COI sequences in introduced .

Similar Taxa

  • AchaearaneaMany Cryptachaea were formerly classified in Achaearanea; separated by 2008 revision based on phylogenetic and morphological evidence
  • TheridionOriginally established as subgenus of Theridion; distinguished by genitalic and web architecture characteristics

Sources and further reading