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The Ohio Journal of Science [Vol. XVII, No. 5, 



Hypoderma lineata. — Only eighty specimens of lineata are 

 represented in the collections, or 1G.5 per cent of the total 

 number obtained. This species is most abundantly represented 

 in northeastern and southwestern Ohio, only 2 collections of 

 1 and 8 individuals coming from the other sections. Eight 

 localities, just as many as is represented by bovis, are rep- 

 resented in the collection from southwestern Ohio, the total 

 number of specimens received being 27. Seven localities are 

 represented in northeastern Ohio, the total number of specimens 

 amounting to 44. 



The earliest lineata collection came from Highland county, 

 on March 25. The latest collection, consisting of 2 specimens, 

 came from Brown county on May 11. The largest number of 

 collections and specimens were received during April, only one 

 collection being received after April 20, the one from Brown 

 county. 



Seasonal Succession of the Species. — That H. bovis is 

 generally later in emerging from the backs of cattle in the 

 spring than H. lineata, is a fact noted by several investigators. 

 This order of their succession is borne out by a study of the 

 data collected in Ohio. It should be stated that in view of the 

 fact that the grubs were squeezed out, many of them were 

 removed at an earlier date than they would have come out 

 naturally. The figures, then, in Table II do not represent the 

 total number of grubs received or removed from cattle, as many 

 of the grubs were not in the fourth stage and hence could not 

 be classified. However, H. lineata is apparently the earlier 

 fly, as only two fourth stage grubs were received after April 20, 

 and an adult fly has been taken as early as May 16. In the 

 H. bovis life history experiments at Wooster, when the grubs 

 were allowed to come out naturally, 17 out of 21 came out in 

 May. 



TABLE II. 



*Prof. Hine has a specimen of an adult fly, H. lineata, taken at Columbus, 

 May 16, 1915. In life history experiments, adults of H. bovis have been obtained 

 in April under laboratory conditions at Columbus, and not until June under natural 

 conditions at Wooster. 



fThis grub was observed in the back of a dairy cow on July 14. On July 20 

 it was discovered to have emerged. As none but bovis have been found in these 

 cattle for several years, it is assumed that this grub belonged to H. bovis. 



