Rhiginia cinctiventris

The concolorous black legs, the lack of a black trapezoidal pronotal spot and the large size will separate this species from R. cruciata . There seems to be geographic variation in the color pattern and size of this species. Western populations (western Texas and Arizona) usually possess black markings on the central part of the head and pronotum and are slightly larger. Eastern populations (central and south Texas to Alabama) tend to have the dorsum of the head and pronotum mostly red or yellow and are often smaller than western individuals. I had entertained the notion that the western population might represent an undescribed species closely related to R. cinctiventris on the basis of the aforementioned differences. I compared several individuals from each of these populations and could find no reliable morphological difference in a long list of examined structures, including the male pygophore. Thus, the differences were attributed to geographic variation. ~drswanny, August 2012.