FAMILY CERAMBYCIDAE 



349 



These small longicorns have the power, like the small buprestids, of at 



times increasing^ in very lareje numbers, and vouner 

 Damage Committed ,, ^, rr , i , • , 



in the Forest. growth thus suffers very severely by their attacks, 



whilst the older trees have their crowns seriously 



diminished owing to the number of branches killed off. 



When the beetle seriously infests young growth the trees should be cut 

 out and burnt. 



Xylotrechus Stebbingi, Gahan. 



References. — Gahan, F.B.I. Coleopt. vol. i, Ceramb. no. 274, p. 244 (1906); Steb. Ind. For. Rec. ii. 9 (1909). 



Habitat. — North-West Himalaya; Kilba, Bashahr State; Jaunsar; 

 Naini Tal, Almora. Gahan gives North-West Himalaya, Bashahr State 

 (E. P. Stebbing), Tibet. 



Tree Attacked. — Quercus dilataUi {mo\:uo:ik). Kilba, Bashahr; Naini Tal, 

 Almora. 



Beetle. — Brown ; head and prothoiax clothed with a greyish 

 pubescence ; the prothoiax with four small brown spots in a 

 transverse row across the middle, two 

 Description. dorsal and two lateral. Elytra sub- 



glabrous, testaceous brown, narrowly 

 covered with grey pubescence at the base, marked with some 

 small spots of ashy-grey pubescence which form three interrupted 

 bands — one near the base, another just before the middle, the 

 third midway between it and the apex ; the apex also narrowly 

 bordered with ashy-grey. Body beneath covered with grey 

 pubescence, a rather large posterior spot on each of the meta- 

 thoracic episterna ashy-white. Head with the lateral carinae 

 oblique, slightly curved, extending below almost to a level with 

 the lower margin of the eyes ; front narrowed between the eyes, 

 furnished with two prominent convergent carinae which are united 

 below. Antennae less than half the length of body ; third joint 

 slightly longer than the first. Prothoiax widest behind the 

 middle, very slightly narrowed in front, strongly narrowed 

 towards the base ; disk with a median asperate carina, which is 



broader and more strongly raised behind than in front. Femora rather strongly thickened ; 

 the hind pair extending a little past the apex of the elytra. First joint of hind tarsi twice as 

 long as the second and third united. Length, 12 mm. to 18 mm. ; breadth, 3^ mm. to 5 mm, 

 [Desc7\ after Gahan.) 



Larva. — Whitish yellow, elongate, the segments of the body more or less of the same 

 size, decreasing gradually posteriorly. Head black. Length about 25 mm. when full-grown. 

 (See fig. 237 (i, \a).) 



The larva of this insect feeds entirely in the bast and outer sapwood of 



the moru oak. I have not as yet taken it in Q. incana. 



Life History. The grub grooves both bast and sapwood, eating out 



large irregular galleries in the long axis of the tree 



(fig. 237 (2)). Occasionally the gallery is quite straight, but it is more 



often irregular and serpentine ; the larva, however, appears to confine 



itself to the layer of wood between the long straight medullary rays. 



Fig. 236. 

 XylotrecJi us Stebbingi, 

 Gahan. N.W. Himalaya, 



