144 THE SCOLYTID BEETLES. 



Typical male: Length 6 mm., black. Agrees with female in every 

 respect, except that it may have stouter mandible, the club of antenna 

 smaller, more elongate; the declivity of elytra with strial punctures 

 finer, and the interspaces without granules. 



Typical male labeled " $ , from Dr. Severin." 



Variations. — Length 7 to 8 mm., average about 7.5 mm.; uniform 

 reddish brown to nearly black, with usual variation in sculpture and 

 vestiture. 



Distinctive characters. — This species is more closely allied to D. 

 punctatus than to any of the other species of the genus, from which 

 it is distinguished by its larger size and stouter form, with the strige 

 scarcely at all impressed, and the punctures smaller. 



The male of this species appears to be far more rare than in the 

 other species, from the fact that among 83 specimens examined only 

 2 males were found. While the declivity is somewhat more shining 

 and smoother in the male, this character is by no means as striking 

 as in the other species of the section to which it belongs. 



The pupa has not been studied by the writer, but is evidently 

 similar in general character to that of D. piceaperda. 



Larva. — Abdominal tergite 8 without, 9 with, small dorsal plate, 

 which is not rugose. Front with distinct elevation. In addition to 

 the generic, divisional, and subdivisional characters, the frontal 

 elevation is subopaque, transversely wrinkled, situated in front of 

 the middle and joined to the epistoma; lateral angles are curved 

 back to their junction with the frontal sutures, which are broadly 

 curved toward the apex. The area behind the elevation is broad, 

 flat, and more shining. Clypeus broad, with faint median groove 

 and the apex broadly emarginate. Labrum small, rather stout, with 

 broad dorsal impression, the apex subtruncate; mandibles shining, 

 with a distinct dorsal impression and oblique ridge near the middle; 

 sternellar lobes of the thoracic segments moderately prominent and 

 with distinct foot calli. 



Type. — One of a large series of larvae received from Dr. G. Severin, 

 conservateur. Royal Museum of Natural History, Belgium. 



The larva of this species is at once distinguished from that of all 

 of the other species of the genus, so far as observed, by the faint 

 dorsal plate of the ninth abdominal segment, by the absence of a 

 plate on the eighth, by the frontal elevation connected with the 

 epistoma, and by the greater number and more distinct hairs on the 

 scutellar lobes of the thorax and abdomen. 



Galleries (fig. 88). — The galleries are evidently quite similar to 

 those of D. terebrans and D. valens, especially in the fact that the 

 larvae live together in a common chamber exposed in the inner bark. 

 According to Dr. G. Severin, the egg gallery is vertical, frequently 



