72 
THE SCOLYTID BEETLES. 
lection of the Bureau of Entomology by 65 specimens in the West 
Virginia Agricultural Experiment Station collection and by more than 
150 in the general Bureau of Entomology collection. 
BIBLIOGRAPHY. 
Hopkins, 1892a, pp. 64-65; Hopkins, 18926, p. 353; Schaufuss, 1892, p. 316; Hopkins, 
1893a, pp. 187-189; Hopkins, 18936, p. 143; Hopkins, 1893c, pp. 186, 213; Hopkins, 
1893a 7 , pp. 123-129; Hopkins, 1894, p. 292; Hopkins, 1894a, pp. 71-76; Hopkins, 1894c, 
p. 348; Lintner, 1895, p. 500; Hopkins, 1896, pp. 246, 250; Hopkins, 1897a, pp. 29-41; 
Hopkins, 18976, pp. 35-36; Hopkins, 1897c, pp. 79, 94-95, 147-151; Chittenden, 1897, 
pp. 67-75; Hopkins, 18986, pp. 104-105; Schwarz, 1898, pp. 81-82; Hopkins, 1899a. 
pp. 394-414, 448; Hopkins, 18996, pp. 11, 13, 14; Chittenden, 1899, pp. 55-56; Hopkins, 
19026, p. 21; Hopkins, 1902c, p. 20; Hopkins, 1903a, p. 59; Hopkins, 19036, pp. 270-275. 
281; Hopkins, 1904, pp. 41, 42, 44; Felt, 1905, p. 6; Hopkins. 
1906c, p. 80; Webb, 1906, pp. 20-22; Hopkins, 1907, p. 163; 
Hopkins, 1909, pp. 90-95. 
Xo. 5. THE ARIZONA PINE BEETLE. 
(Dendroctonus aiizonicus Hopk. Figs. 33, 34.) 
The Arizona pine beetle (fig. 33) is a somewhat 
elongate, brown to black beetle, from 4 to o mm. 
long, with broad grooved head, sides of prothorax 
but slightly narrowed toward the head, finely to 
rather coarsely punctured, and elytra with slightly 
coarse rugosities toward the base and declivity, the 
latter with a few long hairs. (Seefig.34.) It attacks 
healthy, injured, and felled western yellow pine in 
central Arizona, and evidently excavates galleries 
similar to those of the southwestern pine beetle, 
with which it is usually confused. The larva? 
make concealed food burrows in the inner bark, and transform to 
pupa? and adults in individual cells in the outer bark. Like the other 
species, its destructive work would be indicated by pitch tubes on 
the trunk and by the fading yellowish to reddish foliage. 
Fig. 33. — The Arizona 
pine beetle (Dendroc- 
tonus arizonicxis): 
Adult. Greatly en- 
larged. (Author's il- 
lustration. ) 
SEASONAL HISTORY. 
This species was not recognized as distinct from the southwestern 
pine beetle until after the principal field observations had been made, 
and while many specimens were collected they were nearly always 
associated with the latter in similar galleries: therefore there is 
somewhat meager evidence on which to base conclusions relating to 
seasonal history, habits, etc. Apparently, however, its habits are 
in most respects similar to those of the southwestern pine beetle. 
