Walckenaeria communis
(Emerton, 1882)
dwarf spider
Walckenaeria communis is a minute spider in the dwarf spider Erigoninae, measuring only about 2 mm in body length. The is notable for the distinctive horn-like cephalic extension present in some males. It occurs across the United States and Canada, including Alaska and Alberta.
Pronunciation
How to pronounce Walckenaeria communis: //ˌvɔːlkəˈnɪəriə kəˈmjuːnɪs//
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
The combination of minute size (approximately 2 mm), placement in the Erigoninae, and in males the distinctive horn-like cephalic projection distinguishes this . Identification to species level typically requires examination of mature specimens, particularly male or female epigynal structures, as is standard for linyphiid spiders.
Appearance
Extremely small spider with total body length of approximately 2 mm. Some males possess a prominent horn-like extension projecting from the . As a member of the Erigoninae, it has the compact body form typical of dwarf spiders, with relatively short legs compared to body size.
Habitat
Specific microhabitat preferences are not documented in available sources. As a pitfall trap capture in Massachusetts, it likely inhabits ground-level environments including leaf litter and low vegetation.
Distribution
United States (including Alaska) and Canada (including Alberta). GBIF records confirm presence in Alaska and Alberta specifically.
Similar Taxa
- Oedothorax trilobatusAnother Erigoninae dwarf spider with bizarre male cephalic structures; males of O. trilobatus have tumor-like swellings rather than a horn-like extension
- Other Walckenaeria speciesApproximately 70 in , many requiring genitalic examination for definitive identification
More Details
Taxonomic history
Described by Emerton in 1882; the specific epithet 'communis' (Latin for 'common') may reflect its relative abundance in collections or wide distribution
Collection method
Documented from pitfall trap , a standard method for sampling ground-dwelling spiders