Paul Krombholz has an interesting question about Tibicen 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?