Plant Sanitation. 80S 



A COCONUT PEST IN SELANGOR, 



A caterpillar is doing serious damage to coconut palms on an estate in 

 Selangor, says the Malay Mail. As this caterpillar, which is a species of Thosea, 

 or " nettle grub," is omnivorous and will eat both Hevea and Rambong leaves, it is 

 important that on all estates a careful look-out should be kept for the first appear- 

 ance of the pest. 



The caterpillar is easily recognised. It is from one to two inches in length, 

 lozenge-shaped, of an apple-green colour, with bright purple or pink patches on 

 the back. It has bunches of spines or hairs dispersed over its back, and these 

 hairs are cuticating, i.e., ay hen they pierce the skin they cause stinging and irrita- 

 tion. It eats the whole of the soft part of the coconut leaf, leaving only the 

 mid-ribs of the leaflets, and when about to pupate falls off the leaf and spins its 

 cocoon on the ground. These cocoons are dark brown, round or egg-shaped, smooth 

 and compact, and about the size of a large coffee bean. 



The area over which the damage is being done is at present very small — 

 in fact, only a few acres, and rigorous steps are being taken to stamp it out at 

 once. But, if the matter is overlooked at the beginning, the task of eradicating 

 such insect pests is enormously increased. In Ceylon another species of the 

 "nettle grub" attacked a tea field, and in one week after it was first observed it 

 had completely stripped twenty-five acres ; and it was only the most strenuous 

 measures that eventually put a stop to the spread of the evil. 



