14 



INDIAN FOREST INSECTS 



The bast of the teak-tree is eaten by the caterpillar of Dnomitus ceramicus, 

 the grub tunnelling into the wood to pupate ; with the subsequent growth 

 of the tree the tunnels become enclosed in the wood, ruining it for large 

 timber purposes. Species of the genus Xyleborns (Scolytidae, p. 582) tunnel 

 down into the timber. 



Poplar and willow are killed and the wood destroyed by the grubs of 

 the cerambycid beetle ^Eoksihcs sarta (p. 307). 



The bast of green deodar is destroyed by the buprestid Sphenopteva 



(p. 204), by the cerambycid Trinophyllum 

 (p. 340), and by the scolytid beetles 

 Scolytus major and S. minor, and the wood 

 of the tree is tunnelled into by the wood- 

 borer Crossotarsiis (p. 613). 



The bast of the Pinus gcrardiana is 

 riddled and the tree often killed by the 

 beetle Polygraphus trenchi (p. 510). 



To quote two more instances, the 

 wood of the sissu, acacia, Terminalia, etc., 

 is riddled by the wood-borers Sinoxylon 

 crassum and S. anale (p. 152) and bamboos 

 by Dinoderus (p. 133 and pi. ii). 



(c) Damage done to the Branches. — 



The larger branches of the tree, covered 

 by old thick bark, are tunnelled into and 

 destroyed by most of the insects, both 

 bast-eating and wood-boring, which infest 

 the main stem. 



Where the bark commences to thin 

 out, the insects we have already men- 

 tioned as infesting poles will be found 

 to be present, and they occupy all the 

 part of the crown up to the twigs. A 

 little experience will show that the 

 dividing lines between the species in- 

 festing the areas covered by old thick 

 bark, thin younger bark, and the green 

 cortex-covered twigs, are very fairly sharply marked off, each having 

 their own set of insects. There are, however, some pests which 

 infest every part of the tree with the exception of the young green cortex- 

 covered twigs. 



The branches of the sal-tree are infested by a small buprestid beetle, 

 Acmaeodera (p. 193), and by a cerambycid, Xylotrechus (p. 347). The twigs 

 and young saplings of the sal-tree suffer severely from the tapping propensi- 

 ties of the Monophlebus scale insect. 



Fig. 9. — Larval galleries of Hoplo- 

 cerambyx spinicortiis, Newn., in 

 bast and sapwood of sal (much 

 reduced). 



