THE GENUS DENDROCTONUS. 



55 



Prothorax — The form of the pronotuin corresponds to that of the 

 adult and its relative proportions are of some value in distinguishing 

 the species. The number and position of the frontal spines are 

 fairly constant in a species, although they vary in prominence with 



'f,.i-;7ite 1 



': Th-O'le 2 



Tsrr/i/e 3 



'^^'•f^i'/e 4 



Epiph'iirilf 6" 



Hypoplnirile & 



Epiplcui'ilc 7' 



Ih/pvplcu 



Ste.milo 7' 

 Slernitc s'' 

 Sternilc 9 



•^Tergile lO 

 \Tleurili'EpipIcurite 10 



-J 

 \SkrnilclO 



y 



Fig. 38. — Dendroctonus valcns: Abdomen of pupa, lateral and anal aspects, a, Prescutal lobe; 6, seutal 

 lobe; c, scutellar lobe; d, postscutellar area; e, supraanal lobe;/, paranal lobe; j, infra anal lobe; g, pleural 

 spines; r, caudal spine or epipleural spine of the 9th segment; ■?, lateral spines; f, dorsal spines; u, anal 

 opening; iO, tenth segment. (Original.) 



the age of the individual, a§ do other spines of the body, being much 

 less prominent in the older or preimaginal stage. 



Mesothorax. — The mesotergum is subrectangular and without 

 special characters, except, perhaps, in the number and arrangement 



