POLYGRAPHUS MAFOR, MS. 237 

side branches. When found in company with the Tomicus> 
it is generally at the boundary line where the latter’s attack 
ceases and that of the Polygraphus begins. On these thicker 
portions of the tree the pattern made by the beetle is a very 
easy one to recognize, see PI. XIII, fig. c. 
This Polygraphus is undoubtedly a serious pest in the forest, 
and its habit of attacking young growth renders it the more 
necessary that its life history should be well understood and 
that a constant watch should be kept on its operations, so that 
any undue increase on its part may be taken in hand at once, 
I found it also infesting the Pimus Gerardiana, near Kilba, in 
the Sutlej Valley, Bashahr State.} 
1 Since this note went to press, 1 have discovered this Polygraphus 
seriously infesting young deodar saplings in a plantation at Pajidhar in 
the Jaunsar Division, North-West Himalayas. There were some blue pine 
in the plantation, and both were badly attacked by the Polvgraphus. A 
fire had passed through a portion of this plantation in January and the trees, 
weakened but not killed by it, had been attacked by the beetles in May, eggs 
being laid in the trees. The larvze on hatching out had entirely riddled 
the cambium both in the deodar and blue pine, the attack being more severe 
in the latter. It appeared probable at first that the deodar might have 
been infested by the Polygraphus after all the blue pine had been occupied, 
but examination showed that the deodar saplings had been attacked by 
the beetle in previous years. In some of these cases the trees had killed the 
beetles by an outflow of turpentine either in the tunnel when entering the tree 
or in the just commenced egg gallery. In others the galleries in the sapwood 
were half-grown over, the green cambium edge on either side being plainly 
visible. Only one or at most two egg galleries are bored from the pairing 
chamber in the sapwood of the deodar instead of the three which are 
usual when the insect attacks the blue pine. The larvz usually mine 
in the bast only going into the wood to pupate. When this attack 
was discovered (June 25), the beetles of the first generation were matur- 
ing, some having already issued and commenced laying the eggs of the 
second generation in the deodar saplings which were still alive. The 
Polygraphus beetles were mostly in the lower ¢ of the main stem of the 
saplings and not in the tops, the latter being full of the Pityogenes 
contfere beetle, 
The fact of galleries being found partially or nearly entirely grown over 
by the cambium shows-~ 
(1) That the trees must have been attacked by the beetles before the 
growing season of the preceding year. This is of great impor- 
tance since it proves that the beetle will attack deodar even 
when blue pine saplings are available close by. 
(2) That the trees must have been in good health afterwards to have 
7 enabled the cambium layer to have sufficient vitality to per- 
form this work. 
(3) The number of these galleries found was few showing that the 
beetle had not attacked in sufficient numbers to kill the tree. 
The fact that this beetle attacks deodar in addition to blue pine and 
that it can infest green saplings renders it a very serious pest in the forest. 
