Paul Krombholz has an interesting question about Neotibicen identification.
In Kathy Hill’s picture of 18 species, T. canicularis looks quite different from T. davisi, but I have at least one T. davisi, captured in my back yard, that looks very similar to three canicularis individuals I caught in Northern Illinois a couple of weeks ago. The canicularis individuals all have the white “hip” spots and none of my davisi have them have them. T. davisi has a slightly larger head. The big question is, What features reliably distinguish the two species considering all the variety seen within species?
Patterns of pruinosity and patterns of color on the mesothorax are not a reliable means of
identifying cicada species. Pruinosity can vary in cicadas with age.
Head width, wing length, body length, size of opercula and collar color seem to be the only
reliable means of correctly identifying a cicada species from site.
Personally, due to the variations in size of T. pruinosa and T. canicularis, I have a hard time
distinguishing the two without hearing them call.
That is why it is important to be familiar with the species of cicadas in your area as it would
seem that regional variations in color can indeed occur.
All that being said the reliable means of distinguishing T. davisi from T. canicularis is the
thickness of the “W” on the forewings. T. davisi has a thicker “W” than T. canicularis.