Identification
arabesca – small and brightly colored and the pairs of slanting black commas down the dorsum are diagnostic. Body oval shaped.
domiciliorum – “bright white or yellow on the anterior dorsal” - “almost transverse bars on each side of the posterior”
also note Lynette's Forum
here
crucifera (formerly hentzii)-- Seems to be the one with the least well defined pattern.
nautica – “Sides are black with lobed edge toward lighter dorsum”
oaxacensis – body elongate, large southwestern species, relatively unique pattern, but variable. May be confused with Aculepeira!
pratensis – unique dorsal pattern, eastern wetlands
utahana – relatively small, “brown carapace, brown legs, dark brown triangular abdomen, darker on sides; dorsal folium sharply delimited by lighter line
Range
arabesca - Walckenaer, 1842 - AB, AL, AR, AZ, BC, CA, CO, CT, FL, GA, IA, ID, IL, IN, KS, LA, MA, MB, MD, ME, MI, MN, MO, MS, MT, NB, NC, ND, NH, NJ, NM, NS, NY, OH, OK, ON, OR, PA, PQ, RI, SC, SD, SK, TN, TX, UT, VA, VT, WA, WI, WV, WY
crucifera - Lucas, 1838 - AL, AR, AZ, CT, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, MS, NC, NE, NJ, NM, NY, OH, OK, PA, SC, SD, TN, TX, VA, WI, WV
domiciliorum - Hentz, 1847 - AL, CT, FL, GA, IN, KY, LA, MA, MD, MS, NC, NJ, NY, OH, PA, RI, TN, TX, VA, WV
oaxacensis - Keyserling, 1864 - AZ, CA, IN, KS, NM, NV, RI, TX, UT, WA
nautica - Cosmotropical
pratensis - Hentz, 1847 - CT, FL, IL, KS, LA, MA, MI, MN, NC, ND, NY, ON, WI
utahana - Chamberlin, 1919 - CO, KS, LA, NM, OK, TX, UT
Remarks
Some species (usually collectively referred to as "barn spiders", i.e. Neoscona crucifera) are nearly impossible to distinguish from Araneus and can only be separated by examination of carapace to view the carapace groove (fovea). Neoscona have a longitudinal groove on the carapace (parallel with the long axis of the body), whereas Araneus have angular (transverse) grooves. However, an apparent problem is that in Araneus the groove may appear as little more than a dimple, making it tough to tell.
Neoscona
Araneus
