158 FAMILY BOSTRYCHIDAE 



three in the north to five in the south of Burma, three to four in the 

 Central Provinces, four to five in Assam. 



I have not taken S. crassuin in Madras. There seems no reason to sup- 

 pose it is not to be found in the Presidency, since it is known in Burma. 

 The common species of the genus there are, however, S. indicum and 

 S. conigerum, both of which are dealt with later on. 



The life history of this insect shows it to be a pest of a serious nature 

 both in the forest and in the wood depot. In the forest 

 its habit of tunnelling into the young shoots or leading 

 shoots of sal saplings in coppice areas and elsewhere 



makes it a pest of the first magnitude, for it must be remembered 

 that the insect attacks the wood of a variety of trees, and study may 

 show that the beetle similarly feeds in and tunnels into the shoots of one or 

 more of these trees. This phase of its life history requires further careful 

 investigation. 



The beetle is a destructive pest as a wood-borer, not only by its direct 

 action in riddling the timber, and thus rendering it useless save for firewood 

 and greatly reducing the value of billets even for this purpose, but also 

 by its indirect action, in that the large amounts of sawdust thrown out of 

 the borings by the beetles often give good sound logs lying in the forest 

 or depot the appearance of being more seriously riddled, and consequently 

 ruined, than is the case in reality. The depth to which the beetle carries 

 her egg-tunnel varies with the hardness of the heart-wood of the tree, only 

 the sapwood being affected in the case of sissu (fig. 27). In the case of 

 species such as Pterocarpus marsupium and Albizzia procera the beetle goes 

 deep into the interior of poles. 



In the Changa Manga Plantation the beetle exists in considerable 

 numbers, and has in the past done serious damage to the fresh-cut billets 

 and logs of sissu (D. sissoo) both here and in the Shahdera Planta- 

 tion nearer Lahore. I have also found it in numbers in stag-headed and 

 sickly standing green trees. It infests Acacia modesta \vood in the 

 plantation in a similar manner. In the case of the felled material 

 stacked in the Changa Manga Fuel Depot (the plantation chiefly supplies 

 fuel for Lahore), the beetles have in the past so riddled the whole of 

 the sapwood of the stacked billets as greatly to lower their value, or 

 even reduced them to such a condition that their sale could not be effected. 

 Stacks of billets so treated are covered on the outside with a yellowish wood- 

 powder pushed out of the tunnels of the excavating beetles, and the wood 

 has a dilapidated decaying appearance which militates against a chance of 

 its sale, whilst at the same time its weight is greatly reduced, and with this 

 its commercial value (cf. fig. 27). 



At Changa Manga S. crassuin commences laying the first eggs of the 

 year in April, the beetles usually being plentiful in the plantations. In 

 the middle of May but few are to be seen, but the wood-stacks are full of 

 larvae and pupae. A second lot of eggs are laid in June-July, giving rise to 



