Xysticus canadensis
Gertsch, 1934
Canada ground crab spider
Xysticus canadensis is a of ground crab spider in the Thomisidae, first described by Gertsch in 1934. It is distributed across northern North America and extends into Russia. As a member of the Xysticus, it exhibits the characteristic ambush-hunting and flattened body form typical of ground crab spiders. The species overwinters as an or , emerging in early spring to hunt and reproduce.

Pronunciation
How to pronounce Xysticus canadensis: /ˈzɪstɪkəs ˌkænəˈdɛnsɪs/
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Images
Distribution
Found in Russia (from Europe to the Far East), Canada (Alberta, Manitoba, Saskatchewan), and the United States.
Seasonality
are active in early spring, with observations in March and April. Overwinters as adults or immatures, emerging when temperatures rise.
Life Cycle
Overwinters as or immatures. Gravid females have been observed in early spring, suggesting sac production follows soon after. Spiderlings likely emerge in late spring or early summer.
Behavior
Ambush that waits motionless for prey. Has been observed ballooning in fall, climbing vertical surfaces and standing on tiptoe to catch wind for .
Ecological Role
of small arthropods. Serves as prey for spider wasps, including in the Dipogon.
Similar Taxa
- Xysticus sp. (other ground crab spiders)Other Xysticus share the flattened body, ground-dwelling habit, and ambush hunting . Specific identification requires examination of genitalia and other subtle morphological features.
- Thanatus spp. (running crab spiders)Both are crab spiders active in similar seasons and , but Thanatus has a more elongated body and runs actively rather than waiting in ambush.
Sources and further reading
- BugGuide
- Wikipedia
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
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- Bug Eric: Spider Sunday: Spring Spiders