February, '15] BISHCPP-DOVE-PARMAN: HOUSE FLY BIOLOGY 



71 



escaping beneath the cage. The conditions in these tests were not 

 favorable in our opinion for successful wintering, as the amount of 

 manure was small and often it became either too dry or mouldy. 



Examinations of chicken manure in poultry houses in mid-winter 

 showed the presence of considerable numbers of house fly larvae. The 

 conditions in such situations seem especially favorable for the imma- 

 ture stages to pass the mnter as the manure generates very little heat, 

 yet being within the chicken house the insects are not subjected to 

 excessive cold. Livery barns furnish somewhat similar conditions, 

 and often great numbers of larvae are to be found in the cracks of the 

 floors and in corners of stalls. In the South the barns are not heated 

 and the conditions would thus supply uniformly low though moderate 

 temperatures during winter. In the North, where barns are kept 

 heated, there is reason to believe that development and breeding con- 

 tinues during winter in such situations. 



Attention has been called in a previous paragraph to the fact that 

 flies emerged during winter at Dallas and Uvalde, and that warm 

 periods occur even in mid-winter which permit of egg deposition by 

 flies in the open. 



Our observations on the wintering of the house fly indicate that, in 

 the South at least, winter campaigns against the immature stages are 

 of much importance in control. Destruction of the fly at this time 

 may be easilj^ accomplished by thoroughly cleaning out stables, 

 chicken houses, and animal pens and scattering the manure thinly 

 over fields. Large accumulations of garbage or other breeding media 

 should also receive attention. 



President H. T. Fernald: These papers are now open for dis- 

 cussion. 



Mr. T. J. Headlee: I would like to inquire if a test has been made 

 to determine the rate of propagation of the screw worm fly and exper- 

 iments conducted for destroying this fly. 



Mr. F. C. Bishopp: We are still working on the biological aspects 

 but have done considerable work in destroying carcasses. We have 

 learned that upwards of one miUion adult screw worm flies can be 

 produced from one. Our main work of destruction is either by burn- 

 ing or burying. Where we hold the fly down to a minimum, we get 

 very few infestations of living animals. It is a matter of keeping the 

 fly reduced to small numbers. 



President H. T. Fernald : We will now listen to a paper by W. 

 E. Britton: 



