156 FAMILY BOSTRYCHIDAE 



mostly confined to the sapwood, the egg-tunnel being only carried into the 

 outer heart-wood. When poles are attacked, however, the whole structure of 

 the wood is reduced to powder. On becoming full-fed, in four to six weeks (or 

 in the colder parts of the country in eight to ten w r eeks), the grubs pupate in 

 a slightly enlarged chamber at the end of their galleries. This chamber is 

 free of wood-dust, the rest of the larval gallery being blocked with it. About 

 two to three \veeks are passed in the pupal stage. On maturing the new 

 beetles bore or force their way through the mass of powdery material to which 

 the wood has been reduced until they find a female egg-tunnel, up which they 

 crawl, and so leave the tree. If they are unable to find a ready-made exit 

 they tunnel out of the tree for themselves, but the vast majority leave by an 

 old entrance-hole made by the parent generation, and it is for this reason 

 that badly infested poles and trees do not show on the outside the serious 

 nature of the attack to anything like the same extent as is the case with the 

 Scolytidae, as both entrance-holes and exit-holes are far fewer in number. 



Another reason, I have noticed, is that when, as is often the case, 

 S. anale is accompanying S. crassum in its attack, the former and smaller 

 beetle often makes use of the entrance-holes of its larger companion to enter 

 the tree by. Whether this habit is merely laziness on the part of the beetle, 

 or whether it exhibits a certain amount of wide-awakeness, I am unable to 

 say ; but, of course, one of the most dangerous periods of the beetles' lives 

 is that during which they are commencing their tunnel into the wood, and 

 before they have got down flush with the outer surface, for during this time 

 they are exposed to the attacks of their many numerous enemies, both animal 

 and insect. 



A very important and as yet unrecorded feature of the life history of 

 this beetle has rendered it a pest of the first importance, and will probably, 

 in conjunction with the damage done by other insects whose life histories 

 are at present unknown, be found to account for that destruction of 

 young sal growth in the forest for which up to date no cause has been 

 assignable. Whilst the students of the Imperial Forest School were in 

 camp at Phandowalla in the Dun in February 1902, Mr. A. M. Littlewood 

 (now of the Madras Forest Department) forwarded me some small sal 

 shoots and twigs from the sal coppice areas which had been tunnelled 

 into and hollowed out by beetles. I examined a number of these shoots, 

 and subsequently obtained others out in the forests of the Dun and in 

 Garhwal and Kumaun myself. The shoots sent me by Mr. Littlewood 

 contained living S. crassum beetles. The insects had evidently tunnelled 

 into the shoot the previous autumn, the large round entrance-hole 

 being very discernible on the external surface of the shoot, and then 

 hollowed it out, proceeding upwards. Much of the interior of the shoot 

 appeared to have been eaten. The beetle, with the approach of winter, 

 hibernates in the hollowed-out shoot. Instances of this nature, by which 

 an insect commits damage in two distinct forms, are known amongst the 

 Scolytidae, as, e.g., the European Hylurgus (Myelophilus) piniperda, L., of 



