ft92 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XV 



teak trees hatched in from three to four days. The period from the 

 pairing of the moths to the emergence of the larvae from the first eggs 

 laid by the moths does not, I believe, exceed 7 days. The larval stage 

 lasts 2 to 3 weeks, the average time being 16 days. The pupal stage 

 occupies 5 to 9 days, the average being 7 days. For a complete 

 generation, therefore, about a month is required as follows : — 



From pairing of moths to emergence of larva) 7 days. 



Larval stage 16 do. 



Pupal do 7 do. 



Total ... 30 days. 



B. H. puera — 



52. The average period is also about one month, as noted in the 

 case of the generations bred by mo, as follows : — 



From pairing of moths to emergenco of larvae. 

 Larval stage 

 Pupal do. 



Total 



* 



In the few cases for which I was able to obtain accurate dates, the 

 moths lived from 7 to 9 days. The eggs usually hatch in 3 to 4 days. 

 V. Overlapping of the Generations. 



53. In the case of both species the generations overlap one another 

 more or less. 



Of the imagoes of Pyrausta which ultimately developed from the 

 hibernating larvae bred by me in 1900-01, the last one appeared 20 

 days later than the first one. Hence the early larvae of the first complete 

 generation of the year get a start of at least 20 days over the 

 later larvae of the same generation. The same thing probably happens 

 in the case of Hyblcea, and in this species I also found that egg-laying 

 continued for several days, the first larvae of each generation appearing 

 some time before the later larvae of the same generation. In 

 the case of both insects, therefore, all stages of development may be 

 found at one and the same time. As a rule, this is most noticeable in the 

 case of Pyrausta, owing probably to the fact that this species usually 

 occurs in far greater numbers than Hyblcea. 



* It must be understood that the period here given for a complete generation of Hyblcea. 

 refers to cases in which the larva; were bred on the leaves of Millingtonia hortensis. The 

 larvae probably require a longer period to develop when they are fed on teak leaves. 



