8 RICE-PEST OF BRITISH BURMA. 



Tracheal-gill formula of Paraponyx oryzalis. 



which X 2 gives 106, the number of tufts on both sides 

 of the body. 



The caterpillar agrees in all essential particulars of 

 structure and habits with that described more than a 

 century and a quarter ago by De Geer, being a thoroughly 

 aquatic pyralid larva which appears to the naked eye to 

 be covered with a shaggy coat of coarse and transparent 

 (in spirit specimens milky-white) hair, and crawls over the 

 submerged leaves of the plant which it infests in the 

 very midst of the water. De Geer's caterpillar has the 

 habit of cutting off an oblong piece from the edge of 

 a leaf which it applies to a hollow of the leaf, fixing 

 it loosely thereto by means of a few threads of silk, 

 so that the cavity enclosed between the two applied 

 surfaces serves to give lodgment to itself. The 

 upper surface of the leaves of the plant upon which 

 this insect lives happens to be concave. The insect, 

 having an instinctive knowledge of this fact, so places 



