582 FAMILY SCOLYTIDAE 



is true it should be possible to ascertain its local distribution and ex- 

 terminate it. 



A second point of importance is that the insect has been found invariably 

 in pure deodar forests, the greatest damage being caused in young pure 

 plantations. It is much rarer in mixed forests, a point worthy of some 

 consideration. 



Sub-F'aniily 3. — Saetidentatae. 



Edges of middle jaw fringed with bristles. The sub-family contains the tribes 

 Corthylinae (at present unrepresented in the Indian forest) and Xyleborinae. 



Tribe XYLEBORINAE. 



The first joint of the labial palp swollen, and furnished on the inner 

 side with a beard of hairs. Includes the very important and large genus 

 Xylebonis, and the genus Xylotcnis, of which one species only is known from 

 India. 



Xyleborus. 



The genus Xylebonis includes a vast number of species of small form 

 and great economic importance in the East. 



Xyleborus fallax, Eichhoff. 



References. — Eichhoff, Ratio Tomic. p. 508 (1879); Stebbing (Totniciis slioreae), \Jnde~,cr. Scolyt. Ind. 

 Reg. Ind. For. Mew. Zool. Ser. vol. i, pt. ii, 16 ; id. Ass. Sal Ins. Pests, For. Bull. no. 11, p. 39. 



Habitat. — Assam, Bengal Duars. 



Tree Attacked. — Sal [Shorea robnsta). Goalpara, Assam ; Jalpaiguri Sal 

 Forests, Duars. 



Beetle. — Elongate, rather slender, with an elongate convex reddish thorax and dark 



piceous elytra. Prothorax one-fifth longer than broad. Moderately strongly rugose-punctate 



anteriorly with a few scattered yellow hairs ; finely pitted on posterior 



Description. jiortion with iiregular fine transverse lines and striations. Elytra 



irregularly punctate, with an ill-defined stria not reaching base and 



the suture prominent. The apical declivity of elytra furnished with three prominent teeth on 



each side and three smaller ones. .Some scattered hairs on the surface. Under-surface 



slightly punctate and sparsely pubescent. Legs and antennae yellowish red. Length, 3.1 mm. 



(Figs. 4 and 5, pi. Ix.) 



I have taken this insect only sparingly. Specimens were found on 



16 May tunnelling down into the sapwood of a green 



Life History. sal-tree felled in the Kachugaon Forest on the 13th 



of the month. The beetles were tunnelling into the 



main trunk. Ranger B. Sen Gupta cut out some specimens of this insect 



from felled green sal-trees in the Jalpaiguri forests in the Bengal Duars. 



This is all the information at present available on the species. 



