124 Observations on the Habits o/Oscinella frit 



the dates of emergence being noted. Individuals emerging on the same 

 days were caged^ together and sexed after death. 



Synopsis III. Observations in 1920 (Spring). 



Synopsis IV. Observations in 1919 (Summer). 



The last three cages were kept in the shade, 3 feet from ground. 



Conditions under Length of life in days 



which flics were Date of 



kept emergence Sex Minimum Maximum Average period 



.Shade near ground 20.8.19 <J 5 10 7-7 (10 flies 



/Food, nil ? 8 16 11-2 ( 4 



I Moisture, condensation 



I Food, nil 22.8.19 (J 3 5 4-3(3 



j Moisture, nil ... ? 5 11 5-3(6 



iFood, nil 22.8.19 S 6 8 6-6(5 



I Moisture, abundant $ 6 14 11-2(5 



(Food, sugar ... 22.8.19 (J 29 66 50-8(5 



1 Moisture, abundant ? 17 66 50-0(5 



^ The cages were glass cylinders, with muslin covers, standing on several pieces of 

 filter paper, which were placed on a plate. Food was placed in a muslin bag slung inside 

 and the filter paper kept saturated with water. When moisture was withheld, the paper 

 was omitted. 



2 Some evidence as to the probable length of life of the individual early in the year was 

 desired, but winter crops in this district are not heavily infected and time was not available 

 for prolonged searching for puparia among infected grasses. No doubt the average period 

 is low and the maximum period nearer the true period. 



