THE GENUS DENDROCTONXJS. 



103 



collection when examined by the writer on January 12, 1900. The 

 reference in the original description to the front of the head "coarsely 

 granulated, channeled" applies to the type, and at once distinguishes 

 it from the other two specimens which are without a median frontal 

 channel or groove. The "strong transverse impression about one- 

 fourth from the an- 

 terior margin" of 

 the prothorax is as- 

 sociated with the 

 more distinct trans- 

 verse elevation 

 which the author 

 failed to mention. 

 In the writer's re- 

 marks (Hopkins, 

 1905, p. 81) under 

 D. parallelocoUis it 

 is stated that D. 

 parallelocollis Chap, 

 and D. approxima- 

 tus Dietz are evi- 

 dently the same, 

 but further com- 

 parative studies 

 have convinced 

 him that they are 

 specifically distinct. 



Pupa. — In addi- 

 tion to the generic, 

 divisional, and sub- 

 divisional charac- 

 ters, the apex of the 

 front and middle 

 femora have each a 

 minute subapical 

 s p in e ; abdominal 

 tergites 1 to 6 with 

 small pleural spines, 

 1 without distinct 

 dorsal and lateral spines; 2 to 6 with distinct dorsal and lateral 

 spines, increasing in length and prominence to and including tergite 

 6; 7 and 8 smooth; 9 with long pleural spine. Pupal type labeled 

 "Hopk. U. S. No. 5777." 



Larva. — In addition to generic and divisional characters, the front 

 has a broad, but not prominent, median elevation; clypeus short, 

 broad, with apex truncate; pro thoracic segments with prominent 



Fig. 64. — Dendroctonus approximatus: Egg galleries. (Original.) 



