Fr.^ 



i 



38 G PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



The seasonal history of Chilo simplex is most irregular. Many larvse- 

 begin to rest from September and may continue to do so till July or 

 even August next year. On the other hand moths have emerged up 

 to 12th December and oviposition has been observed to continue in the 

 fields up to the earher part of November. Again, from the same batch 

 of eggs laid in September some larvae have been observed to develop 

 into moths in the earlier part of the cold weather while the others rested 

 till the following July. The earliest date after the cold weather on 

 which moths have been observed to emerge from over-wintering larvse 

 is the 13th of May, The time when over- wintering larvae generally 

 develop into moths is May to July. But active feeding caterpillars, 

 apparently hatched from eggs laid after the winter, have been collected 

 on the 10th April and the eggs from which these larvae developed must 

 have been laid towards the end of March. Therefore the shortest abso- 

 lute resting period when no activity is observable extends from about 

 December to about March and the longest resting period so far noticed 

 lasts from about September to about July or August. Some larvae 

 have been observed to continue their rest 43eyond July but they died 

 in August and it is not known whether they would have rested, till the 

 hot weather in the following year. While over-wintering larvae rest 

 in this manner, normal successive broods occur in the case of those 

 which become active in spring. (Plate 44, fig. 2.) 



The shortest and longest periods required for the completion of the 

 life-cycle in the warm weather during the active season have been 

 observed to be 36 and 63 days respectively, viz., egg 3 to 5 days, larva 

 28 to 50 days and pupa 5 to 8 days. In the case of resting larvae the 

 life-cycle may take up to about nine months. 



The creamy- white flattened scale-like eggs are deposited on the stem 

 or leaves, more usually on leaves in clusters, and overlapping one another 

 like the tiles on a roof. The clusters stick to the substratum like scales. 

 When the eggs hatch, the young larvae walk down into the heart of such 

 plants as maize and juar. Some may be disturbed by the waving of 

 the leaves by wind and let themselves clown with silk and are thus blown 

 on to neighbouring plants. They are active creatures, capable of walk- 

 ing over the ground to neighbouring plants and effecting their entrance 

 into the stem through the side. In the worst cases the plants may be- 

 riddled by the larvae and maize and jiiar which are somewhat grown 

 may not show " dead heart " although their stems may be bored through 

 alid through. The larvae pupate inside the stem. 



It is really a pest of maize, juar and rice. Maize is mainly attacked 

 when young and practically wholly avoided when mature. Juar is 

 however attacked in all stages. It occurs in rice throughout the season 



