A REVISION OF NORTH AMERICAN CHRYSOBOTHRINI 37 



Elytra at base subequal in width to apical half of pronotum, twice as long as 

 wide ; sides parallel from humeral angles to apical third, then arcuately con- 

 verging to the tips, which are conjointly broadly rounded ; lateral margins serrate ; 

 basal depressions broad and deep; humeral depressions shallow; disk rather 

 strongly convex ; surface finely, rather densely punctate, more or less rugose, 

 sparsely clothed with short, erect, white hairs, the intervals feebly, densely 

 granulose. Each elytron with two or three vague costae behind the middle, and 

 two vague foveae, one in front of middle and the other near apical third. 



Abdomen beneath sparsely, coarsely, shallowly punctate, sparsely clothed with 

 long, recumbent, whitish hairs, with smooth lateral callosities, the intervals 

 densely, finely granulose ; last visible sternite broadly, rather deeply emarginate 

 at apex (emargination truncate in middle), the lateral margins serrate; eighth 

 tergite broadly rounded at apex, densely, coarsely punctate, densely granulose, 

 but not longitudinally carinate. Prosternum coarsely, densely punctate, more 

 or less transversely rugose, rather densely clothed with long, semierect, white 

 hairs ; anterior margin with a broad, very short, median lobe. Anterior femur 

 with a short, obtuse tooth, which is dentate on outer margin. Anterior tibia 

 slightly arcuate, with a small, emarginate dilation near apex; middle and 

 posterior, tibiae straight. 



Length 5.2 mm., width 1.6 mm. 



Female. — Differing from the male in having the head uniformly reddish cupre- 

 ous, the antenna piceous, with a slight cupreous tinge, the last visible sternite 

 serrate and broadly rounded at the apex, the prosternum smooth at the middle, 

 and more sparsely pubescent, and the anterior tibia unarmed near the apex. 



Redescribed from the male type and female allotype in the collection 

 of W. J. Chamberlin. 



Type locality. — Coconino County, Ariz. 



DISTRIBUTION 



From material examined : 



Arizona: Coconino County, May, types (W. J. Chamberlin). Ashfork, June 18; 



Williams, May and June (Barber and Schwarz). Peach Springs, May 1934 



(F. T. Scott). 

 California : Sunset Valley, Santa Barbara County, July 4, 1939 (W. F. Barr). 

 Colorado: Durango (E. J. Oslar). 



Hosts. — The larval habits are not known, but E. A. Schwarz in 

 his unpublished notes records the adults as being abundant on juniper 

 (Juniperus sp.) at Ashfork, Ariz. 



The specimens examined are rather uniform in coloration but vary 

 considerably in the width and shape of the pronotum. The pronotum 

 varies from nearly parallel-sided anteriorly to widest at the middle, 

 with the sides regularly rounded. The broader specimens usually 

 have the elytra widest behind the middle, whereas in the more cylin- 

 drical ones the sides of the elytra are parallel to behind the middle 

 as in the type. The sculpture on the elytra is more or less variable as 

 to the distinctness of the costae and foveae. The length is from 5 

 to 8 mm. 



This species is very closely allied to lixa Horn, but in arizonica the 

 clypeus is a little more deeply emarginate in front, and the hairs on 

 the elytra are sparser and average less than one-tenth of a millimeter 

 in length, whereas in lixa they average at least one-tenth of a milli- 

 meter. The males of arizonica usually have the apex of the last visible 

 abdominal sternite more truncate at the middle, and the genitalia 

 twice as long as in lixa, with the median lobe rounded at the apex. 



