FAMILY SCOLYTIDAE 609 



Xyleborus ? sp. 

 Habitat. -Tezpur, Assam. 

 Tree Attacked. — Seinul {Bombax malabariciim). Tezpur. 



This small scolytid is one of the semul-wood borers, and is a pest 

 of considerable importance. Soon after the trees are 



Life History. felled this beetle tunnels down into the wood to ovi- 



posit, the eg^-tunnels beinj;- carried in to a varyinj^ 

 distance, sometimes reachinj^- deep down in the wood. The eggs are laid 

 near the bottom of the tunnel in small offshoot galleries. The grubs would 

 seem to be ambrosia feeders, since they do no wood-tunnelling themselves. 

 They pupate in these small galleries, and the beetles, when mature, crawl 

 into the main egg-gallery and up this, and so escape from the tree. A gene- 

 ration of the beetles evidently appe irs on the wing in the semul areas 

 in January or February, and tunnels into newly felled trees to lay its eggs. 

 These trees are subsequently sawn up into planks in the sawmills for tea- 

 boxes, probably during the following hot weather and rains, and the wood is 

 then found to be riddled with the minute galleries of this beetle. At times 

 the wood is so full of the galleries that the planks are seriously weakened 

 thereby, and the portions so infested have to be discarded. 



At the commencement of April igo6 I visited a sawmill near Tezpur, 

 where semul-logs were being cut into planks and small boards for the 

 preparation of tea-boxes. As soon as cut, the small boards are stood up 

 against one another in small. heaps to dry, as the wood is still full of sap. 

 I examined a number of these small planks, and found many of them scored 

 with the tiny galleries of this insect. From many of these galleries I took 

 live beetles, some maturing and others apparently tunnelling into the fresh 

 wood to lay eggs. 



From its method of attack in the semul, this small scolytid is a pest of 

 some importance ; and in sawmills it would be well to burn all seriously 

 infested planks, and to burn all fresh refuse material in which otherwise the 

 beetle might be likely to oviposit, and so breed out fresh broods to carry on 

 the infestation of fresh timber as it arrives in the mill. 



Undetermined Scolytid. 



Habitat. — Tharrawaddy, Lower Burma. 



Tree Attacked.— /I ^z«a {Naucka) sessilifolia. Konbilin Forest, Tharra- 

 waddy. 



I took some specimens of a minute scolytid tunnelling into a green 



stump of Adina sessilifolia, in company with Platypus 



Life History. siiffodiens (p. 621), in the last week of January 1905. The 



tunnels of the scolytid are easily distinguishable from 



those of the platypids, owing to their much smaller diameter. The beetles 



9003 g Q 



