In the northern and western parts of the pronotalis range (particularly the "Great Plains"), these cicadas tend to be slightly smaller and considerably more variable in coloration, pruinosity and pronotal pattern.

There is some evidence to suggest both pronotalis and dealbatus form a blend zone or introgression zone. The increased pruinosity seen in some pronotalis specimens from the central Plains States approaches that seen in T. dealbatus. The abdomen may even appear "striped" dorsally or flanked with silvery-white wax as seen in dealbatus and dorsatus/tremulus - case in point, as seen here in this specimen of T. pronotalis!