74 



Habits of the Tomato Moth 



on the 30th day to knotgrass it was too feeble to feed and died the 

 following day. 



4. On tomato 12 larvae commenced to feed and growth was very 

 slow. On the 26th day two only remained alive. Of the rest one had 

 died of the flacherie disease and the others of no apparent disease. Of 

 the survivors on this day one weighed -06 g. and the other -11 g. The 

 smaller one, which experience showed would have died on a tomato 

 diet, was transferred to knotgrass, and in nine days it outstripped the 

 larger one and then grew rapidly and uninterruptedly, pupating with 

 a weight of -94 g. on the 50th day of active life. The growth of this 

 larva is represented in Diagram I by the broken line from the point 



11 pupated 



Ipupated 



died 



o io o ^ 



m lo cd co 



Age in days 



Growth of larvae on : — 

 Knotgrass Tomato Knotgrass following tomato 



Diagram I. Contrasting the growth of a batch of larvae on Polygonum and Tomato. 



where it was transferred from tomato. The remaining one continued to 

 grow slowly on a diet of tomato foliage till the 46th day, when it ceased 

 to feed for two days and lost weight. A ripe tomato fruit was then 

 supplied to it and it fed readily on this for a few days, subsequently 

 feeding alternately on foliage and fruit. It was not weighed after the 

 57th day but it was seen to be feeding little and died on the 76th day. 

 The growth of this series fed solely on tomato, is shown in Diagram I 

 by the continuous line, and is in striking contrast to the development 

 on knotgrass. 



(c) A small batch of eggs, found on Chenopodium growing on a 

 rubbish heap in a nursery, was divided into two parts, half being placed 



