6/29/15 Spider of the Day
Infraorder Araneomorphae (True Spiders)
No Taxon (Entelegynes )
Family Thomisidae (Crab Spiders)
Genus Xysticus (Ground Crab Spiders)
Another lawn mower tenant !
Ozyptila and Xysticus are both distinguished
from either Coriarachne or Bassaniana by the lateral profile of the
carapace: as Lynette mentioned, in both Coriarachne and Bassaniana the
carapace is roughly flat all the way from front to back. The side
profile of the carapace for Ozyptila and Xysticus, on the other hand,
will be higher near the front and will drop down near the back at around
coxa three. Coriarachne and Bassaniana maintain roughly the same level
height from front to back.
So, the order of things to check when separating Xysticus, Ozyptila, Coriarachne and Bassaniana is:
1) Check carapace flatness first, to separate Coriarachne and Bassaniana from Ozyptila or Xysticus
2) Then, check the ventral macrosetae on tibia I and femur I length/width ratio to separate Xysticus from Ozyptila.
Ozyptila: - no more than 2 pairs of ventral macrosetae on tibia I …. femur I length-to-width ratio is about 3:1
Xysticus: - 3 to 4 pairs of ventral macrosetae on tibia I …. femur I length-to-width ratio is about 4:1
Information from BugGuide