578 



FAMILY SCOLYTIDAE 



X8 



Scolytus (Eccoptogaster) deodara, Stebbing. 



References.— Stebbing, Ind. For. Mem. Zool. Ser. vol. i, pt. ii, 23 ; id. Depart. Notes, vol. i, 220. 



Habitat.— Jaunsar, Simla Hill States, Bashahr, Chamba. 



Tree Attacked.— Deodar {Cedrns deodara). North-West Himalaya. 



^' '■- iiim.uiki Beetle.— Intermediate in size between S. 



major Tindtninor. Black, moderately shining, 



cylindrical, the elytra 

 Description. tinged with rufous 



brown. Head thickly 

 striate behind the eye with close-set vertical 

 striae which are produced down on to the 

 ventral surface, this striation not being pre- 

 sent in 6". minor. Prothorax not longer than 

 broad, not so thickly punctate as is head, the 

 punctures finer and fewer behind. Elytra fairly 

 thickly striate-punctate, sparsely covered with 

 yellow hairs, especially laterally, as are pro- 

 thorax and head. Antennae yellowish brown ; 

 legs rufous brown, tarsi yellow. Length, 

 3.2 mm. to 3.5 mm. 



Larva. — When just hatched the young 

 larva is a minute white circular ball. 



This beetle apparently makes its 

 first appearance 

 Life History. in the year in 



the forest about 

 the middle to the third week of June, 

 i.e. not long before the first burst of 

 the monsoon rains. Its method of 

 egg-laying is quite unlike that of the 

 other two species of Scolytus known 

 to infest the deodar. 

 The female beetle selects the leader of a sapling or the branch of a 

 large tree which may have a thickness of as much as three-quarters of an 

 inch in diameter, and proceeds to girdle it. The beetle tunnels first into 

 the branch down to the cambium layer, and then eats out a deep groove in 

 the bast and sapwood in a horizontal manner round the branch, this groove 

 completely girdling the stem. The beetle manages to keep such an even 

 course on its way round the stem that it usually hits off to within a fraction 

 the point where it started from (vide fig. 363, b.) Small notches are cut 

 out on the upper side of the groove and an egg laid in each. These notches 

 are usually cut only on the shady or northern aspects of the branch, and the 

 groove is generally deepest on this side, so that when the weight of the 

 branch causes it to break and bend over it falls on this side. The number of 

 eggs laid in one girdled branch is as many as eight, and may be a few more. 



Fio. 363. — Scolytus deodara, Steb. a, 

 dorsal and side view of beetle ; b, part of 

 girdled shoot showing point of girdle and 

 larval galleries in sapwood above girdle (bark 

 removed). 



