THE GENUS DENDROCTONUS. 151 



23. Dendroctonus valens Le Conte. 

 (PL VII, fig. 23.) 



Adult. Typical female: Length, 8.7 mm. Head with front broad, 

 convex, and with broad anterior impression. Epistomal process 

 broad, with lateral sections oblique. Pronotum with punctures 

 moderately coarse, much smaller and denser toward base. Elytra 

 with a few long hairs toward base; declivity convex; striae impressed, 

 with small distinct punctures; interspaces moderately convex, dis- 



rctly rugose. 

 Typical specimen labeled, name label, "Hopk. 1/22/08, Pinus 

 ponderosa, Hopkins, collector, McCloud, Cal., 9 , Hopk. U. S. 18a." 



Typical male: Length 7.6 mm. Differs from female in stouter 

 mandibles, narrower antennal club, more opaque declivity, less dis- 

 tinctly impressed striae, and more obscure punctures. 



Typical male labeled same as female. 



Variations. The length ranges from 5.7 to 9 mm., with the aver- 

 age about 8 mm. The color of the elytra, pronotum, and vertex 

 of head ranges from light to dark red, but is never black, while the 

 ventral part of the body varies from light red to black. The great- 

 est variation is in size, but there is a wide and remarkable range 

 in the epistoma and front and in the sculpture of the pronotum 

 and elytra, as in almost every other character. Thus a large num- 

 ber of individuals may be easily selected, each of which might be 

 considered as representing a good species, but when a large series 

 of specimens is examined from any given faunal region or locality 

 no sufficiently distinctive and constant characters have been found 

 by which they can be readily recognized as distinct from those of 

 any other faunal region, so that those examples from Maine can 

 not be distinguished from examples collected in the mountains of 

 Mexico. 



Distinctive characters. The characters which serve to distinguish 

 this species from D. terebrans, to which it is closely allied, are its 

 prevailing red color, the less uniform and more densely placed 

 pronotal punctures, the much broader epistomal process, with the 

 lateral sections less angular and more oblique, and the more evident 

 and numerous hairs on the anterior dorsal area of the elytra. 



Revisional notes. See same heading under D. terebrans. 



The typical specimen on which Le Conte's original description 

 (Le Conte, 1860) was based is from California and represents the 

 common red form which has heretofore been confused with D. tere- 

 brans. The distinguishing character, " finer and denser punctures of 

 the thorax," mentioned by Le Conte is undoubtedly a good specific 

 character when taken with color and other characters. The species 

 is represented in the Le Conte collection by the type and 9 speci- 



