Xysticus emertoni
Keyserling, 1880
Emerton's Crab Spider
Xysticus emertoni, commonly known as Emerton's crab , is a of ground crab spider in the Thomisidae. It occurs across a broad transcontinental range spanning North America and Eurasia, including the United States, Canada, Russia, and Central Asia through China. As a member of the Xysticus, it exhibits the typical crab spider body plan with laterally extended legs adapted for ambush . The species has been documented as for in the genus Dipogon.
Pronunciation
How to pronounce Xysticus emertoni: /ˈzɪstɪkəs əmərˈtoʊnaɪ/
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Identification
Members of the Xysticus can be distinguished from other crab genera by their relatively flattened, oval and habit of resting with legs extended laterally in a crab-like posture. Xysticus typically have shorter, stouter legs compared to flower-dwelling crab spiders in the genus Misumena. Identification to species level requires examination of genitalic structures under magnification. Xysticus emertoni may be confused with other Xysticus species, particularly X. elegans and X. ferox, which share similar ground-dwelling habits and coloration.
Images
Habitat
Ground-dwelling; found in leaf litter, grass tussocks, and low vegetation. Has been observed on concrete paths and trails, suggesting of disturbed or edge .
Distribution
United States; Canada; Russia (Urals to Far East); Kazakhstan; Central Asia; China; Slovakia.
Seasonality
active in early spring (March documented in Colorado), with females observed before sac production. Overwinters as adults or immatures.
Life Cycle
Females produce sacs guarded in silken retreats. occurs as or immatures, not within egg sacs.
Behavior
Ambush that waits motionless for . Exhibits ballooning for : climbs vertical objects, stands on tiptoe with tilted skyward, and releases threads to catch wind currents. Highly sensitive to motion; quickly retreats to cover when disturbed.
Ecological Role
of small . Serves as for (), particularly Dipogon . Contributes to through and as prey for higher .
Similar Taxa
- Xysticus elegansOverlapping distribution and similar ground-dwelling habit; requires genitalic examination for reliable separation
- Xysticus feroxShared preferences and general ; subtle differences in color pattern and
- Misumena vatiaAlso a crab (Thomisidae) but distinguished by longer legs, flower-dwelling habit, and ability to change color