FAMILY SCOLYTIDAE 



Figs. 2, 2 a show the dorsal and side views of the female beetle ; 2 />, 2 c the same 

 of the male beetle ; 2 d shows the antenna enlarged ; and 2 e a leg. 



Larva. A small white elongate worm with a yellowish head. The grub, instead of being 

 curved as is usual with bark-boring scolytid grubs, is more or less straight, and tapers slightly 

 posteriorly. Fig. I shows the larva. 



Pupa. Whitish yellow, with ordinary beetle shape. 



The following notes on the life history are compiled from observations 

 made in the field during the latter half of May and the 



Life History. first half of June 1908. The life history of the insect 

 for the remainder of the year is at present unknown. 



The male insect flies to and settles on the outer bark of the oak-tree, 

 and then bores into the bark, eating out a straight tunnel, of the same 



diameter as itself, down to the 

 kast l a y er anc ^ sapwood of the 

 tree. On reaching the latter it 

 gnaws out a small chamber which 

 grooves both the bast and sap- 

 wood and is squarish in appear- 

 ance (pi. lii). When this work 

 is complete, or before the male 

 has finished the pairing-chamber, 

 a female enters the orifice of the 

 entrance-tunnel of the male in the 

 bark and works her way down- 

 wards, enlarging the tunnel as she 

 goes in (as she is larger in cir- 

 cumference than the male), till 

 she reaches the male in the pair- 

 ing chamber. After pairing with 

 the male the female commences 

 to eat out a gallery in the sap- 

 wood and bast ; this gallery takes 

 a direction away from the pairing- 

 chamber, and is always more or 



FIG. 351. Dryflcoctc.s Hewetti,?,\.zb. i, 

 larva ; 2, 2 a, female ; 2 />, 2 c, male beetle ; 

 2d, enlarged antenna; 2 c, leg. North- 

 West Himal lya. 



less at right angles to the long axis 

 of the tree (pi. lii), in this differing 

 from other Indian Scolytidae,* 

 in which the gallery bored by the female is parallel to the long axis of the 

 As she eats out this tunnel, the female makes little indentations 

 in the edges on both sides and places an egg in each. When she 

 has completed the gallery, which is the egg-gallery, i.e. when she has 

 laid all her eggs, she dies in situ at the head of the gallery. Before 

 the gallery is completed, however, the larvae from the first-laid eggs 



Scolytus major, Polygraphus major, Sphaerotrypes siwalikensis, etc. 



