52 6 FAMILY SCOLYTIDAE 



larvae pupate here as well, except in the case where small branches are 

 infested, when the pupating-chamber is eaten out in the sapwood to some 

 extent. The beetle lays as many as sixty to seventy eggs, half being laid on 

 each side of the tunnel (fig. le). The larvae from the eggs laid on the outer 

 side of the tunnel appear to do best. 



The insect passes through three to four life-cycles in the year. 

 The first eggs of the year would appear to be laid in the trees during 

 April, the first generation of beetles issuing towards the beginning of June. 

 The eggs laid by these beetles produce a second generation some time in 

 August, which is followed by a third about the middle of October, which 

 lays the eggs which hatch out into the larvae to be found in the trees in 

 November. These larvae either mature into beetles which hibernate in 

 the trees, or they themselves pass the winter in their tunnels. It is 

 quite possible that in favourable years there may be a complete fourth and 

 partial fifth generation of the insect in the year. 



The beetle is a common pest of the pine in Kumaun and in areas to the 

 west Jaunsar, Tehri Garhwal, Chamba, and Bashahr. 



This Polygrapkus must be classed as one of the more formidable of the 

 scolytid pests of the chir pine, since it will infest trees 



of a11 a S es from the sma11 seedlin and sapling to the 

 oldest tree, and it attacks green trees. I have taken 

 it in small saplings newly killed in the Buldhoti Plantation in Kumaun, and 

 in a large standing green tree near Kathian in Jaunsar. In freshly blown 

 down and newly felled trees in Bashahr and Chamba I have taken the 

 insect in large numbers occasionally, having found it infesting the tree from 

 crown to base of stem. It often accompanies the large Tomicus pest, 

 T. longifolia (described later on), in its attacks on the tree. 



I felled two newly dead trees in the Buldhoti Plantation on 7 June 

 1908. The one, a sapling of 8 in. girth, had the yellow needles still on the 

 branches. An examination showed that the tree had been attacked from 

 crown to base of trunk by this beetle, the egg and larval galleries covering 

 nearly all the branches and main stem (fig. is). The attack had probably 

 commenced in the previous October and been continued by the April (1908) 

 beetles laying the eggs of the first generation of the year. The second tree, 

 one of 2ft. 6 in. girth, was a green standing tree showing evidences of 

 being in a very sickly state, there being considerable masses of resin exuding 

 in "tears" down the bark. An examination showed it to be severely 



j 



by the Cryptorhynchus brandisi weevil, the Nothorrhina muricata 

 longicorn, and this Polygraphus beetle. P. longifolia was not in so advanced 

 a stage here as it was in the sapling ; larvae, pupae, and immature beetles 

 being present in this tree. I have already alluded to the fact that I took 

 the beetle fairly numerously from the base of a large green tree of 14 ft. 

 girth, standing closely adjacent to the Range Office at Kathian in Jaunsar. 

 This tree was situated at about the upper limit of this pine in Jaunsar. 



