98 



THE SCOLYTID BEETLES. 



Type labeled ''Type No. 7518, U.S.N.M., individual l/'name label, 

 ''n. sp., Hopk., 4/18/02," name label, ''1/15/08, A. L. Herrera, col- 

 lector, 9 , Sacramento, Amecameca, Mexico." 



Male type: Length, 4 mm.; front with moderately prominent fron- 

 tal tubercles each side of the distmct groove. Pronotum with rather 

 distinct transverse elevation across the entire area similar to that of 

 the female; elytral declivity more uniformly convex; striae more 

 impressed and deeply punctured and interspaces more convex and 

 distinctly rugose. 



Male type labeled " Type No. 7518, U.S.N.M., individual 5," remain- 

 ing labels same as on female except sex label. 



Variations. — Length from 3 to 4.5 mm.; aver- 

 age about 3.8 mm.; color from brown to black. 

 The prescutal ridge is more prominent in some 

 females than in others and is present in some 

 males and absent in others. 



Distinctive characters. — This species is more 

 closely allied to D. arip.onicus than to any of the 

 other species of the division to which it belongs 

 and is distinguished from it by the presence of 

 short, reclining hairs on the pronotum, less dis- 

 tinctly impressed elytral striae, and more evident 

 short pubescence of the elytra. 



Revisional notes. — It is evident that this spe- 

 cies was not represented in the material studied 

 by Blandford. The size comes near that of his 

 D. adjunctus, but the characters as given b}^ 

 him to distinguish this species from D. parallel- 

 ocollis at once distinguish it from D. mexicanus. 

 The pupa and larva have not been seen. 

 Gallery (fig. 59). — A small section of the gal- 

 lery, evidently of this species, was received with the specimens of 

 adult from Prof. A. L. Herrera. This indicates a winding egg gallery, 

 with the eggs isolated, the larval mines concealed in the inner bark, 

 and the pupal cells in the outer bark. 



Distribution (fig. 60) and host trees. — The specimens received at dif- 

 ferent times from Prof. A. L. Herrera and Dr. S. J. Bonansea were 

 evidently from Pinus teocotl, P. lejophilla, and P. ayacahuite in Ame- 

 cameca, Michoacan, and Tacubaya, Mexico. 



Identified specimens. — Thirty-six specimens of adults and one speci- 

 men of work were identified for Professor Herrera and Doctor Bonan- 

 sea, a set of which were returned to them and the remainder retained 

 for the forest insect collection of the Bureau of Entomology. 



Fig. 59. — Dendroctonus mex- 

 icanus: Section of egg gal- 

 leries. (Original.) 



