Mar., 1908 .] GlRAULT I LlFE-CYCLE OF PSEUDOPYRELLIA. 



L5 



LENGTH OF THE LIFE-CYCLE OF PSEUDO- 

 PYRELLIA CORNICINA FABRICIUS FOR 

 A SINGLE GENERATION, WITH 

 RECORD OF A PARASITE. 



By A. Arsene Girault, 

 Washington, D. C. 



On the morning of August 20, 1907, at New Richmond, Ohio, I 

 found a single mass of 66 eggs of this common coprophagous species 

 freshly deposited on cowdung in a meadow. These were taken up and 

 placed on fresh droppings in the laboratory. They hatched at about 

 six o'clock on the morning of August 21, and the larvae at once 

 entered into the dung. 



By noon of August 23, the maggots were of some size, and pupa- 

 tion followed two days later, at 6 P. M., August 25, average time. 

 The flies commenced emerging nearly simultaneously at 7 A. M., 

 September 2, and again at about the same hour, September 3, making 

 the average time of emergence, 7 P. M., September 2. The table 

 shows the duration of the different stages : 



The eggs when first obtained were placed on fresh cow droppings 

 confined over moist loam soil in a glass jar, covered with cheese cloth. 

 This jar was confined in the laboratory, out of direct sunlight. The adults 

 lived for two weeks after emergence, similarly confined over human 

 excrement, but they did not deposit eggs ; they were confined singly, 

 and also in numbers together. 



About noon, August 20, adults of the parasitic Cratospilafuscipennis 

 Brulle were frequently observed crawling over piles of cow droppings, 

 and a few of them were seen probing their ovipositors into the halt- 

 grown maggots of cornicina. Afterwards, many were reared from 

 these larvae brought into the laboratory. They appear to be quite 

 abundant in that locality of Ohio. This is the first recorded parasite. 



