44 U.S. NATIONAL MTJSEUAI BULLETLN" 290 



nevadensis, the pronotum from the dorsal view is stouter than that of 

 c. confluentus. 



DisTEiBUTiON. — The types of this subspecies were taken in Nevada; 

 no other specunens are known to me. 



Cryptocephalus confluentus confluentus Say 



Figures 16, 90, 121 



Cryptocephalus confluentus Say, 1824, p. 440. 

 Cryptocephalus confluens Say, of authors. 



Pronotum: Orange to reddish (rarely blackish), usually vdth light 

 yellowish markings in two basal oblique spots and at lateral and apical 

 margins, usually darkest (sometimes black) basally on each side, light 

 margins variable, often vague. Punctation dual, smaller punctures 

 minute and dense, larger punctures very small, infrequently rather 

 small and coarse. 



Elytra: Background color creamy yellow to light orange, vittae 

 brown to black. Each elytron with three dark vittae as follows: on 

 second interval, usually complete, sometimes vague apically; on fourth 

 interval, sometimes vague or interrupted before middle, rarely vague 

 at basal half and apex; on sixth interval, often vague or reduced at 

 base. With seven distinct and even rows of punctures and a short 

 series behind humerus, punctures fine, dense as usual, finer to apex as 

 usual; inner and outer rows distinct at apex and nearly or quite 

 meeting. 



Prosternum: Anterior margin in male produced ventrally into a 

 distinct, pointed lobe or spine, in female produced ventrally into a 

 distinct, sometimes pointed lobe. 



Length: 4.0 to 5.7 mm. 



Discussion. — Haldeman (1849, p. 253) used the spelling confluens 

 for this species as have nearly all authors since; I believe, however, 

 this is an unjustified emendation and that the original spelling 

 confluentus is correct. 



Two specimens from Mexico determined as C. ahrwptus Suffrian are 

 similar to this species. They differ in that the yellowish pronotal 

 markings (two basal spots and the lateral and apical margins) are 

 distinct (not vague as in c. confluentus) and the vitta on the second 

 elytral interval is interrupted or incomplete apically (nearly always 

 complete in c. confluentus). Also each elytron bears a small, dark 

 subhumeral spot; this is absent in c. confluentus. 



Tilden (1949, p. 151) recorded this species on Baccharis jpilularis 

 consanguinea O. Ktze. (Astereae), 



Label data provide the following records: Chrysothamnus, Chry- 

 sothamnus speciosus Nutt, and Gutierrezia lucida Green. 



