AND OTHER IXJl'RIOUS INSECTS OF 1 907 AND I908. 



153 



P. iiitcla and the variety iicbris were found working in |)lants ac 

 the very beginning of the investigations, and their larvae were dis- 

 covered as late as August 18th. The first pupa was found August 8th, 

 and no larvae were found after August 18th. The first moth of this 

 species emerged August 31 ; the last moth euTerged September 17th. 

 The length of the pupal stage, as siiown by the records of several bred 

 specimens is about twenty-two days (from nineteen to twenty-five) 

 on the average. 



Fig. 77. The same I'sg cluster a-' sliowii in preceding figure enlarged >.}]4 

 times. Originjil. 



Eggs were laid in a breeding cage by an unmated female on Sep- 

 tember 7th. Several moths were placed in a breeding cage over a giant 

 Bur-elder plant, and presumably mated. These, for the most part 

 were of the variety nebris, though one or two were typical nitcla. 



Eggs were laid in two clusters or masses on the base of the plant 

 stalks, between one and two inches from the ground, there being be- 

 tween fifty and sixty eggs in each mass. Eggs were also scattered in 



