FAMILY BOSTRYCHIDAE 



171 



forms the pairing-chamber. This chamber may have only the one entrance- 

 tunnel (fig. 116, ^), or there maybe two entrance-tunnels into it made by the 



male and female, as shown in 





) 



^ 



Fig. 1 16. — A, gallery of Siiioxyloii anale in a khair 

 branch. B, galleries in a sissu billet ; a a, entrance- 

 galleries of S and 2 ; fi, pairing-chamber ; c c, egg- 

 galleries. Kumaun and Changa Manga. (E. P. S.) 



figs. 116, £), and 117,/!. In any 

 event, the male appears to 

 fertilize two females at least, 

 as two egg-tunnels are found 

 to leave this pairing- chamber. 

 These go down at an angle 

 from the pairing-chamber, but 

 are never carried into the 

 heart-wood, this bostrychid 

 being a sapwood feeder only. 

 The eggs are laid at intervals 

 in the egg-tunnel, and the 

 larvae, on hatching out, feed 

 usually in the long axis of the 

 tree or log. The larval gal- 

 leries, unlike the beetle egg- 

 tunnel, which is kept entirely 



free from wood-dust and particles, are blocked with wood-dust and excreta 

 throughout their entire length, save for the slight enlargement of the 

 tunnel at the end which forms the pupal chamber. This chamber is blunt 

 elliptical, is free from wood-dust, and is eaten out parallel to the long 

 axis of the tree, as shown in fig. 117, B. On maturing, the beetle either 

 eats its way out through the wood and bark above it till it reaches the out- 

 side, or, when the wood is badly attacked, eats upwards until it cuts into an 

 empty egg-tunnel, up which it creeps to the outside. 



From the above description it is obvious that it is quite easy to dis- 

 tinguish the egg-tunnels made by the beetles from the larval tunnels packed 

 with wood-dust and excreta. These latter are not so easily traced, how- 

 ever, in damp timber as in drv. 



This beetle is one of the most destructive wood-borers in India. 

 Observations have shown that it will tunnel into and 

 oviposit in (i) dying trees, (2) dead trees, (3) fresh-cut 

 logs and firewood billets, and (4) old, dry, or even 

 rotting (if dry) materials. 



In infesting wood materials in this manner, the beetle is somewhat 

 exceptional. It is more usual for these wood-borers to confine themselves 

 to wood in a certain stage of humidity, dryness, or decay, and only to 

 attack wood in this condition. S. anale does not appear to restrict itself in 

 this manner, for I have taken it in standing dying but green trees ir> 

 which the flow of sap, though weak, was still making its presence felt, as 

 also in newly dead trees, in old seasoned logs, and in decaying billets. The 

 green healthy tree is not attacked by the beetle, and therefore it cannot be 



Relations to the 

 Forest. 



