FAMILY SCOLYTIDAE 



605 



Beetle. — (J Dull, head and thorax black, elytra dull rufous brown apically. Head with front 

 deeply concave to eyes, very densely, finely, and uniformly punctate ; antennal club pubescent, 



rest almost hairless. Thorax with apical 

 Description. margin evenly rounded with a median cleft, 



sides rounded and produced outwards me- 

 dianly, thence constricted gently to basal angles which are slightly 

 produced, base bisinuate, produced medianly ; surface with a median 

 line most prominent in basal portion and not reaching to anterior 

 margin, punctate, the punctures rather large and shallow, the inter- 

 spaces very finely punctate. Elytra with basal margin raised and 

 bisinuate ; striae deeply impressed, the two inner ones obsolete 

 towards basal margin, the third not cjuite reaching the margin, the 

 surface irregular with a few scattered punctures, the interstices 

 broad, finely reticulate with irregularly transverse punctures, strongest 

 apically ; alternate interstices carinate from two-thirds up to apex, 

 the surface of carinae irregularly punctate, ending in a fine sharp 

 black spine with a few sparse yellow hairs beneath. Apical declivity 

 light reddish brown with a very short sparse yellow pubescence. 

 Under-surface black. 



Fio. 



384- 



Scolytoplatypus hinia- 

 layeiisis, .Steb., sp. nov., 



in silver fir. 

 North-West Himalava. 



5 Head and elytra shining, red-brown, thorax black, dull. 

 Head globose, shining and smooth on vertex, dull and finely and closely punctate on front 

 and sides, a slight brush of hairs over mandibles. The median line less prominent, not 

 extending beyond the median pore, which is moderate in size and filled with a short golden, 

 tuft of pubescence, the punctures similar to male on disk below the pore, but above it and 

 laterally they merge into a fine dense reticulation. Elytra smooth, shining, with interstices 

 similar throughout, broad, rather flat, uniformly and finely reticulate with a few scattered 

 punctures. Under-surface black, the last two abdominal segments light yellow-brown. 

 Length, $ 3.2 mm. ; $ 4 mm. 



The differences in the thorax are sufficiently distinct to distinguish the species from 

 mikado, Blandford, and the head from raja, Blandford. 



This beetle matures and leaves the tree in the latter part of June 



at high elevations (8,000 to g,ooo ft. and over). In 



Life History. igoQ I was fortunate enough to discover it infesting 



a blown silver-fir pole which was still partly green. 



A few larvae and pupae were taken, but the insect was mostly in the 



mature-beetle stage, and some of the generation had already left the 



tree. 



The male beetle tunnels into the tree through the bark, and on reaching 

 the sapwood eats out a short gallery in the bast and wood, usually com- 

 pletely in the latter. This is the pairing-chamber, and a female enters to 

 him here and is fertilized. After fertilization, the female tunnels down into 

 the sapwood at an angle for about an inch, and then eats out a straight 

 gallery parallel to the long axis of the tree. From this main gallery she gnaws 

 out little offshoot tunnels at intervals on either side, from one-fourth to 

 one-third of an inch in length. These little offshoot tunnels are usually 

 from six to eight in number, and are made alternately on either side.. 



