Cryptorhynchus Illiger, 1807

Anderson, Robert S., 1807, A Review of the Genus Cryptorhynchus Illiger 1807 in the United States and Canada (Curculionidae: Cryptorhynchinae), The Coleopterists Bulletin 62 (1), pp. 168-180 : 169-170

Key to species of Cryptorhynchus Illiger in the United States and Canada

1. Elytral strial punctures very large and deep, most as wide as adjacent intervals and some wider than adjacent intervals; apical one–third of elytra with bright white scales, distinctly contrasting with dark scales on rest of elytra; femora each with two large, distinctly separate teeth; male with ventrite 5 flat, not modified................................................... C. lapathi (Linnaeus)

1’. Elytral strial punctures small to moderately large, shallow to moderately deep, none as wide as adjacent intervals; apical one–third of elytra with scales similar in color and pattern to rest of elytra, not distinctly contrasting with scales on rest of elytra; femora each with one or two teeth; male with ventrite 5 slightly impressed medially, with deep median fovea or with pair of small scale-tufted tubercles............................................................ 2

2. Legs long and slender, femoral length 4.4–5.4X maximum width; front femora with very small tooth situated slightly beyond distal one-third of length; head above each eye with small glabrous shiny tubercle; pronotum with uniformly appressed scales; elytra with concentrations of dark appressed to suberect scales on intervals 3 and 5 near base; male with ventrite 5 feebly concave at middle............................................ C. helvus LeConte

2’. Legs shorter and more robust, femoral length 3.9–4.3X maximum width; front femora with one or two teeth, if one, then tooth situated at more or less midlength or slightly beyond; head above each eye punctate (if small glabrous shiny area present, then femora with two teeth); pronotum with tufts or concentrations of black, erect scales on anterior margin on each side of middle and laterally and on midline at midlength or with erect scales evenly distributed over disk; elytra with concentrations of erect scales on intervals 3 and 5 near base and at about midlength; male with ventrite 5 broadly shallowly impressed medially, with deep median fovea, or with pair of small scale-tufted tubercles............................................................ 3

3. Front femora with two moderately large to large separate teeth, distal tooth longer than proximal tooth, or with teeth broadly fused together at base and with distal portion longer than proximal portion; male with ventrite 5 with broad deep median fovea....................................... C. obliquus Say

3’. Front femora with two small to moderately large separate teeth, distal tooth shorter than proximal tooth, or with single tooth situated at about midlength; male with ventrite 5 broadly shallowly impressed medially or with pair of small scale-tufted tubercles..................................................... 4

4. Pronotum with uniformly distributed erect or sub-erect scales, not arranged in concentrations or tufts; width almost as wide as elytra at base, about 1 1/ 3X wider than long; male with ventrite 5 broadly shallowly impressed medially....................................................... C. tristis LeConte

4’. Pronotum with distinct tufts of black scales on either side of middle on anterior margin, laterally and on midline just anterior to midlength; width distinctly narrower than elytra at base, only very slightly wider than long; male with ventrite 5 with pair of small scale-tufted tubercles situated near basal margin............................................... C. fuscatus LeConte