TWO NOTORIOUS INSECT PESTS. 691 



47. As noted above, the larva? of Pyrausta, when feeding on the 

 teak leaves, do not, as a rule, roll up the edge of the leaf, but lie on tho 

 exposed leaf surface below a light weft of silk thread. On tho other 

 hand this rolling of the leaf-edge to form the larval shelter is very 

 characteristic of tho Hyblcea larva when feeding. 



48. Again, when about to pupate, the larva of Pyrausta usually 

 takes advantage of the most convenient depression or cavity available 

 within which to construct the cocoon. In the case of damaged, dead 

 and withered loaves, the naturally curled-up edge forms such a cavity, 

 and pupation in consequence often takes place in it. Here, however, 

 the rolling of the leaf is primarily due not to the insect but to natural 

 causes. That this is so, is also shown by the fact that, when the 

 Pyrausta larva pupates on green teak leaves, pupation in the rolled -up 

 edge is quite the exception. In this case ; naturally curled-up edges 

 are rare and the larva consequently makes the best of a depression along 

 the midrib or a lateral vein, making the cocoon there by drawing the 

 sides of the leaf loosely together by threads of silk. 



The Hyblcea larva, on the other hand, when it pupates on the leaves 

 on which it has been feeding, constructs the pupal shelter in the same 

 way as the larval shelter which, in the case of teak leaves, is usually by 

 rolling up the end or edge of the leaf. 



49. Further it appears probable that when, as is often the case, 

 the larvae of both Pyrausta and Hyblcea are feeding together on teak 

 trees, the larva? of Pyrausta will sometimes utilize the empty larval 

 shelters made by the Hyblcea larva? and vacated by them, as conveni- 

 ent places for pupation. Any one casually finding the Pyrausta Ian ?& 

 or pupje in these shelters, under the curled-up leaf edge, would be apt 

 to conclude that the rolling was done entirely by Pyrausta, whereas 

 the Hyblcea larva Is probably responsible for it. 



50. For the above reasons I think the term " teak-loaf roller " is 

 as applied to Pyrausta, a misnomer which is apt to give an incorrect 

 impression regarding the habits of the larva. 



IV. Period required for one complete Generation. 

 A. P. machceralis — 



51. Although I have made several attempts with more than fifty 

 imagoes, I never succeeded in obtaining eggs from the moths kept in 

 captivity. The life of the imago is, however, a short one and does not, 

 as a rule, exceed 8 days. All eggs, also, found by me on the leaves of 



