FAMILY SCOLYTIDAE 



481 



Life History. The grubs of this beetle feed upon 

 those of the sal bark-borer. The clerid has the same 

 diameter as that of the bark-borer beetle, and can 

 thus enter after the latter into its tunnels and oviposit 

 there. 



It is obvious that since this beetle is an enemy 

 of the bark-borer it should never be killed. The beetles 

 or their grubs are always to be found in company 

 with the sal bark-borers, and probably pass through 

 the same number of generations in the year as their 

 hosts. The Xipoiiins hibernates in the beetle stage in 

 thick sal-bark in a manner similar to that of the bark- 

 borer. (Vide additional note on p. 490). 



FIG. 317. 



Niponius andreiuesi, 

 Lewis. Upper and 

 Lower India, Assam. 



Sphaerotrypes assamensis, Stebbing. 



REFERENCES. Stebbing, Some Undescr. Scolyt. from Ind. Regions, Ind. For. Mem. Zool. Ser. vol. i, pt. i, 

 p. 4(1908) ; id. Some Assam Sal Insect Pests, Ind. For. Bull. no. n, p. 23 (1907). 



Habitat. Assam and Bengal Duars Sal Forests. 



Tree Attacked. Sal (Shorea robusta). Goalpara, Bengal Duars. 



Beetle. Small, globular, very convex above. Black, slightly shining. Prothorax uni- 

 formly punctate, with a slight longitudinal median line. Elytra with deep longitudinal striae, 



the interstices being filled with rows of elevated prominent black 

 Description. scales. There is a row of stiff short hairs on the anterior margin 



of prothorax. Easily distinguished from .sv'uvj/Y/vv/.f/V by the 



deeper striae on the elytra, which become more pronounced as they approach the apex, 

 instead of becoming obsolete ; by the black colour of the elytra and by the more open 

 and definite punctation of the elytra ; also by the more strongly raised line on the pn>tlx>r.i\. 

 Distinguishable from coimbatorensis (as is siivalikensis] by the much more obtuse angle 

 formed by the junction of the bases of the elytra, the angle being sharply V- sna P et l in 

 coimbatorensis ; the larger size also distinguishes it from this latter. Under-surface black. 

 finely punctate ; antennae yellow ; tarsi piceous brown ; tibiae set with a fringe of white 

 hairs. Length, 2.8 mm. to 3.6 mm. Fig. 318, a, b. 



Larva. White, short, squarish in outline, dorsal surface slightly convex. Head small, 

 yellow. Resembles a large white tick in appearance. 



The beetle makes its first appearance some time earlv in March ;md 

 lays its eggs in the bast and sapwood of newly felled trees 



Life History. or in standing sickly ones. The upper part of the trunk 

 and the crown of a large green tree felled in February 



were found to have been badly attacked soon after felling; the genera- 

 tion of beetles raised in them issued at the end of April, ;uid in the 

 middle of May had already oviposited in neighbouring trees. None of 

 these beetles or others of the same generation had oviposited in the bark 

 of this tree since it had become too dry. They require absolutely green cam- 

 bium. The male beetle bores down about a quarter of an inch into the bark of 



9003 H H 



