5oS 



FAMILY SCOLYTIDAE 



Fig. 331. — Niponius canalicollis, Lewis, predaceous 

 upon Polygi-aphus, Scolyii/s, and other bark-borers. 

 North- West Himalaya and Suliman Mountains, a b, en- 

 larged ; a \, natural size. 



Life History. — This Niponius is a common scolytid predator in the 

 mountainous ranges of North-Western India. It enters the tunnels of the 



bark-borers through the 

 orifices in the bark (its 

 diameter being equal to 

 or less than that of the 

 insects it preys upon) and 

 lays its eggs in the egg- 

 gallery of the bark beetle. 

 It is, I think, possible that 

 it also feeds upon the eggs 

 of the latter. The Niponius 

 grubs on hatching attack 

 and devour those of the 

 scolytids. They are elon- 

 gate and flat in shape, and 

 are thus able to make their 

 way between the bast and sapwood from one larval gallery to another to 

 get at the grubs. 



The duration of the life-cycle of the insect appears to coincide with 

 that of its hosts — from six to eight or ten weeks, and the number of 

 generations passed through during the year varies from three to five, 

 according to the elevation it occupies, the season, etc, A rather remark- 

 able fact about the insect is that it is to be found attacking bark beetles 

 infesting trees living at different altitudes in the mountains, and that it also 

 has a wide range. It has been found in the deodar, blue pine, spruce, 

 and Pinus longifolia in the Western Himalaya, and in the Pin us 

 gerardiana in the Suliman Range in the far west. 



The insect was first discovered in igoi in Jaunsar, and observations 

 made in India upon it and other bark and wood Histeridae confirm 

 Mr. G. Lewis's opinion that numbers of the family follow bark- and wood- 

 boring Scolytidae into their tunnels to prey upon them. 



The beetle has some resemblance to the Scolytus beetles of the deodar 

 (cf. pi. Ivii, fig. I, c i), from which it should be distinguished. It is of great 

 importance that forest officers should be able to recognize this valuable ally. 



Thanasimus himalayensis, Stabbing (p. 186). (The Bark-beetle Predaceous 

 Clerid.) — This is one of the most important and valuable of the bark-beetle 

 predators. It is a clerid beetle closely allied to the Clems formicarius 

 of European coniferous forests. It feeds with avidity on the Polygraphus 

 and many other scolytid and platypid bark- and wood-borers. I have found 

 the insect throughout the coniferous forests of the North-Western Himalaya. 



Beetle. — Head and antennae black ; body short and squarish, with well-marked 

 " shoulders." The prothorax is black and has some hairs on it. The body, which is 

 covered by the elytra, is broader than the prothorax and head ; the elytra are rounded 

 at extremities, the basal third being red, the rest black ; the black area is traversed by 



