NORTH AMERICAN BOSTRICHIDAE 129 



distinct, arcuate, yellowish hairs, sparsely, finely punctate at sides, 

 coarsely, deeply, densely punctate on disk, impunctate on apical de- 

 clivity, apical declivity with lateral submargins slightly elevated, 

 united with lateral margins, obtusely rounded on top, and curving 

 inward to near exterior tubercles at anterior margin ; sutural margins 

 not distinctly elevated ; each elytron with two costif orm tubercles along 

 anterior margin of apical declivity, the tubercles obtusely rounded at 

 apices. 



Abdomen beneath densely, finely punctate, densely clothed with 

 short, recumbent, whitish hairs, with a few long, erect hairs inter- 

 mixed on last visible sternite, which is broadly rounded at apex. 



Female. — Differs from the male in having the front of the head 

 flattened or concave, glabrous, shining, finely and sparsely punctate, 

 with two small, distinct tubercles at the middle behind the eyes, the 

 clypeal suture distinct and sulciform, the clypeus strongly convex, the 

 left mandible more strongly toothed on inner margin near apex, and 

 the last visible abdominal sternite thickened at the apex. 



Length 5-7.5 mm., width 2.5-3 mm. 



Type locality. — Colorado Desert, at New River, Calif., type in the 

 LeConte Collection in the Museum of Comparative Zoology, Cam- 

 bridge, Mass. 



Distribution. — From large series of specimens examined from many 

 localities in Arizona, California, and Purissima, Lower California. 



Hosts. — This species has been reared from paloverde (>Gercidium 

 torreyanwm (Watson) Sargent), mesquite (Prosopis juliflora 

 (Swartz) de Candolle), and tamarisk (Tamarix gallica Linnaeus). 



In a series of specimens there are very few constant characters for 

 separating aspera and sericans. The first segment of the antennal 

 club is variable in shape, and cannot be depended on entirely for sepa- 

 rating the two species, as are also the markings on the front of the head. 

 In sericans the punctures on the elytra are not quite so coarse, and are 

 finer and obsolete toward the apical declivity, and the pubescence is 

 more conspicuous and longer. Both species have about the same food 

 habits, and may represent but one slightly variable species. 



Dendrobiella sericans (LeConte) 



Sinoxylon sericans LeConte, 185i8, Acad. Nat. Sci. Phila. Proc. 10 : 73. 

 Xylopertha sericans Gorham, 1883, Biol. Centr.-Amer., Coleopt, v. 3, pt. 2, pp. 



215-216, pi. 10, fig. 21 : 1886, sup., p. 353. 

 Dendrobiella sericans Lesne, 1901, Soc. Ent. de France Ann. (1900) 69: 491-492, 



494-495, figs. 271, 280-281 ; 1933, C. R. Congr. Soc. Savantes de Paris, p. 238, fig. 



8 (publication not available) ; 1938, in Junk (pub.), Coleopt. Cat., pt. 161, p. 56; 



Anderson, 1939, Wash. Acad. Nat. Sci. Jour. 29 (9) : 391, figs. 35, 40-41, 44-45 



(larvae). 

 Dendrobiella pulescens Casey, 1898, N. Y. Ent. Soc. Jour. 6: 67, 68; Belkin, 1940, 



Ent. News 51 : 192. 



Male. — Dark reddish brown, base of elytra and legs usually more red- 

 dish ; antennae, palpi, and tarsi, brownish yellow. 



Head moderately convex, slightly depressed at middle behind eyes, 

 with two small tubercles concealed by the pubescence on front, these 

 tubercles sometimes obsolete, densely, coarsely granulose, densely 

 clothed with long, erect and recumbent, yellowish hairs on front ; cly- 

 peus sometimes longitudinally grooved at middle, finely, sparsely punc- 

 tate, sparsely clothed with short, recumbent, whitish hairs; clypeal 



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