JOURNAL 



OF 



ECONOMIC ENTOMOLOGY 



OFFICIAL ORGAN AMERICAN ASSOCIATION OF ECONOMIC ENTOMOLOGISTS 



Vol. 9 JUNE, 1916 No. 3 



/ 



DISPERSION OF MUSCA DOMESTICA LINNJEUS UNDER 

 CITY CONDITIONS IN MONTANA 



Contribution from the Laboratory of the Montana State Board of Entomology, 

 State College, Bozeman, Mont. 



By R. R. Parker 

 Introduction 



The Montana State Board of Entomology has been conducting an 

 intensive study of certain conditions which directly or indirectly affect 

 the question of fly control in Montana. During the season of 1914 

 data were collected to determine what species of flies are found in 

 cities and towns, their comparative abundance, their seasonal abun- 

 dance, what conditions favor their abundance and what general and 

 local economic conditions must be considered in outlining control work. 

 The detailed results are as yet unpublished. During the season of 1915 

 it was found advisable in continuing the work to devote considerable 

 attention to the dispersion of the house-fly under city conditions. 

 Miles City was selected as eminently suited for such work because of 

 three facts; namely, the great abundance of flies, the representative 

 size of the city and the lack of efficient control measures. The dis- 

 persion investigation and its results are discussed in this paper. 



Review of Previous Dispersion Experiments 



The importance of the radius of fly dispersion with relation to 

 house-fly control propaganda and the spread of disease organisms by 

 this insect has been responsible for several attempts to accumulate 

 experimental evidence. Arnold (1907)^ in Manchester, England, 

 liberated 300 flies marked with a spot of white enamel and recovered 

 five at distances of 30 to 190 yards. Copeman, Howlett and Merriam 

 (191 1)'^ conducted experiments at Postwick, England. Flies marked 



