FAMILY SCOLYTIDAIi 



551 



PITVOPHTHORL'S. 



Pityophthorus sampsoni, Steb., sp. nov. 

 (The Blue Pine Hvanch Giniler.) 



Habitat.— North-West Himalaya. 



Tree Attacked.— Blue Pine (Finns cxcelsa). Jaunsar, N.W. Hinialava. 



Beetle. -Elongate, oblong. Very dark piceoiis brown. Head tinely 

 punctate and reticulate. I'rothorax with base finely margined, trnncate, 

 sides behind very shgiitly oblique, rounded in 

 Description. front and sinuate below apex, latter obtusely 



rounded and scarcely crenate : the surface in the 

 anterior halt with a number of aspeiations arranged transvcr.-ely, most 

 prominent anteriorly : the posterior half rugose-punctate. Elytra slightly 

 narrower at base than prothorax, wider apically, fully twice as long as 

 prothorax, sides straight to apical fourth, thence constricted, apex obtusely 

 rounded ; the basal area with transverse striae ; rest glabrous, punctate, 

 the punctures in rows, interrupted by small transverse striae and rugo- 

 sities ; ihe suture raised and glabrous ; declivity nearly vertical, moderately 

 shining, punctate, with a few weak tubercles, the outer margins raised. 

 Under-surface almost black, punctate, and strongly pubescent. Length, 

 1.7 mm. 



1 take pleasuie in naming the species after Colonel V. Winn Sampson. 



Flc. 354. 

 Piiyo p h t li or MS 

 .sampsoni, sp. 

 nov., Stebbing, in 

 blue pine. N.W 

 Himalava. 



This small scolytid infests the blue pine, attacking and girdling the 

 smaller branches of the tree. I first discovered the 

 Life History. insect in May 1902, between Deoban and Koti Kanesar 



in Jaunsar. I noticed that several blue-pine trees passed 

 had a nuitiber of their smaller branches either dead or dying. Investigation 

 showed that it was usually the secondary branches taking off from the 

 main side branches that were affected in this manner. These branches 

 were either upright, or in their normal position, on the tree, but with the 

 needles dead and yellow or withering ; or in other cases the branches were 

 hanging down as if half-broken from the tree. If these latter are pulled 

 they will come away, and it can be seen that at the point of fracture the 

 branch has been girdled, and a mass of exuded turpentine will usually 

 be found at this point. This girdling is done by the female beetles, the eggs 

 being laid in the branch above the point at which it is girdled. In this way 

 a provision of slowly dying cambium is provided for the tiny larvae which 

 hatch out of the eggs laid. Several larvae were taken in individual twigs, 

 so that each beetle lays more than one egg in the twig she girdles. From 

 some twigs I obtained beetles just mature on 22 May. In others full-grown 

 larvae were present. The larvae feed entirely in the bast layer and outer 

 sapwood, eating small wavy galleries up the girdled twig, and pupating at 

 the end of them. When mature the beetle eats its wa}- out through the 

 bark co\'ering the pupating-place of the grubs. 



The beetle sometimes girdles the branch at its juncture with the main 

 branch, at others chooses a point higher up. In any event the whole of 



