CHAP. XVI. | BEETLE PESTS OF CROPS. 153 



Another ally of the cockchafers is the Palm Beetle (Oryctes 



rhinoceros) which bores into the tender shoots of palms, aloes, and 



sionally into In this case it is only the adult beetle 



which does damage, the larva living a harmless existence as a fat, 



white grub win. d commonly in decaying vegetable matter 



dead leaves, manure pit-, rotten wood, dead aloe or palm stems, 



etc. The beetle itself not only does considerable dan boring 



through the tender unexpanded leaves ol palms, bul its tunnel 

 provides a suitable entrance forthestill more destructive Red Palm 

 Weevil (Rhynchophorus ferruginous) which is thus enabled to lay 



its eggs in the tender growing parts of the palm from which its 

 larvae burrow downwards into the stem and, when in large numbers, 

 may kill the tree, whose rotten stump presently becomes a suitable 

 nidus for the larva- of the palm beetle. So that it will best-en that 

 these two beetles are to some extent mutually interdependent and 

 that the damage done by one is completed and amplified by the 

 other. 



Manx beetles bore into the solid wood of growing trees or bushes 

 in their larval Stage and do very serious damage to the plants so 

 attacked. The longicorn beetles in particular have white wood- 

 boring larva. 1 which are usually long, stout, cylindrical, with distinct 

 nents and well-developed jaws. In the case of the larger grubs 

 which bore into trees, of which Batocera rubus in mango and 

 rubber and the coffee borer (Xylotrechus quadripes) in coffee are 

 well-known examples, the larva may be cut out and the wound 

 painted over with tar, a drastic remedy which is usually quite 

 successful. But the besl method of control is prevention by hand- 

 collection of the beetles when these emerge before they have 

 opportunitj oi laying their eggs; one coffee-borer killed at this 

 time may save twentj hushes bored by grubs lati 



Soni- of the Buprestidse arc also wood-borers in the 



grub stage, their white larva being usually elongate and with a 

 curiouslj dilated thoracic region. Sphenoptera gossypii is a local 

 pest of cotton in Bellary whilst S. arachidis attacks groundnut 

 ami Leguminosse practically throughoul the plains, being an 

 his pest of groundnut in South Arcot. The only 

 thing to be done in the case of these small borers is promptly to 

 pull out and destroy all the plants attacked by them. 



Though a true longicorn ami wood-hour in it- carls stages, 

 Sthenias grisator deserves special mention, as the beetle has the 

 curious habit of girdling twigs of Erythrina, rose, etc., by seizing 

 them in its jaws and ringing them completely by biting through 

 the bark so as t" .<rrest all tl • In the end of the branch 



thus killed the eggs are laid and the larva" tunnel and live, the 



