584 FAMILY SCOLYTIDAE 



in very dry wood. In the latter, old galleries of previous years were 

 discoverable, but no new ones or beetles. From this it would seem to be 

 possible that these wood-borers — and the same has been noted in several 

 other instances — confine their attacks to a certain condition of the wood 

 during its seasoning process. When the wood has reached a definite degree 

 of dryness the}'' will no longer attack it. The beetles when discovered on 

 24 April were egg-laying. 



I subsequently found this Xylebonis in some numbers tunnelling into 

 the sapwood of a green sal-tree felled on 13 May 1906 at Kachugaon, in 

 Goalpara. The beetles were mostly taken between the i6th and 20th of that 

 month. They were all found in the sapwood and had not yet penetrated 

 down into the heart-wood. They were here tunnelling into absolutely 

 fresh wood full of sap, apparently with the object of egg-laying. 



Whilst in Lower Burma in 1905 I noticed this scolytid appearing 

 in some numbers on the evening of 21 January just before sunset, in the 

 Tharrawaddy forests. I obtained no specimens of the insect on sub- 

 sequent evenings, and it became apparent that on the evening in question 

 a swarm of this insect had just reached maturity and left the tree or 

 plant the insect infests. The insects were flying around and inside the 

 Myaungbinzin Bungalow, built of teak and thatched with grass, bamboos 

 being used in the construction of the walls. The teak posts and rafters 

 and the bamboos used in the construction of the bungalow were earth- 

 oiled, so it was not definitely ascertainable that the insect came from 

 either of them. 



On the following da}', however, I found the first beetles of the year 

 mature and maturing in a large felled Ano<::;ciss!(.s tree. The tree had 

 been felled in a tounggya clearing in the previous year (May). These 

 clearings are made in the forest with the object of creating teak plantations, 

 the grantee being allowed to fell the trees, fire the area, and then to take a 

 crop of rice off the area provided he sows on it at the same time teak seed 

 at intervals of 6 ft. by 6 ft. 



The wood of the large tree in question was still fresh, although the bark 

 was dry in the upper part. 



A few belated white curved larvae were also found at the bottom of 

 the egg-tunnels. The female beetle tunnels straight through the bark 

 down into the sapwood for a certain distance, and then the tunnel 

 diverges to the right or left. At the bottom of the tunnel she lays four to six 

 eggs. The larvae appear to be ambrosia feeders, as they do not feed upon 

 the wood. The beetles, when mature, crawl up the mother egg-gallery and 

 escape from the tree. The beetles mature and maturing on 22 January 

 were issuing to lay the eggs of the first generation of the year, i.e. the first 

 generation of 1905. The beetle was infesting the tree in company with the 

 platypids Platypus rectangulatus and P. solidns (p. 623). 



