294 The Ohio Journal of Science [Vol. XVII, No. 8, 



Cluster flies were also collected outside on the 8th and 17th 

 of December, in the old biology building on the 10th of January, 

 in a bath room January 19th, and again at the Columbus 

 Sewage Disposal Plant, March 3, 1917. They were collected 

 quite abundantly outside during a warm period on March 20th. 

 These early specimens, however, appeared to be freshly emerged 

 for their thoraces glistened with the full supply of golden hairs. 

 In older specimens these become broken so that only a small 

 bunch of them remain on the pleura. 



Some of these cluster flies caught in traps March 21st and 

 others swept from the west wall of the Domestic Science 

 Building, were placed in a breeding cage over banana and a 

 layer of wet clay, a method previously used by Hutchison. 

 Single eggs were found scattered on the clay on March 24th, but 

 these did not hatch. They were placed in petri dishes on a 

 moistened strip of blotting paper where they were enclosed 

 with a living green earthworm {Allolobophora chlorotica), 

 which has been reported as its host. The angleworm was 

 found in the truck garden near the surface in spring and 

 summer, but often 2 to 3 feet under the surface in winter. 

 These worms were brought in from the garden occasionally 

 in the winter and examined under the binocular, but no parasites 

 were observed. 



On the 31st of October, 1916, puparia of Pollenia rudis were 

 taken in the truck garden at a depth of 2 to 6 inches. These 

 were placed in breeding vials in the laboratory where one female 

 emerged on the 1st and a male on the 11th of November. 



There is plenty of evidence that Pollenia rudis hibernates 

 as adult, although the apparent appearance of fresh spring 

 specimens suggests that it hibernates in the immature stages 

 also. 



CONCLUSION. 



It has been recommended repeatedly that the adults of flies 

 be killed in early spring in order to reduce the numbers of later 

 generations, but from the evidence brought forth by these 

 winter observations on various Muscids, the maggots and 

 puparia should also receive attention. If manure piles, 

 rubbish heaps and the like, where larvee and pupse may winter 

 successfully, are given proper attention during late fall and 

 winter, the immature stages of these flies would be more exposed 

 to fatal temperatures and their numbers thereby reduced. 



