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Vol. XLII. LONDON, MAY, 1910. No. 5. 



CHRYSOPHANUS DORCAS KIRBY, AND RELATED SPECIES 

 IN THE UPPER PENINSULA OF MICHIGAN. 



r.Y WILLIAM W. NKWCOMB, ^LD., DETROrr, MICH. 



The principal object of this paper is to present some observations 

 upon three species of C/irysophanus, dorcas, epixa/ithe and heiloides, which 

 were found in Dickinson County during the summer of 1909, while the 

 author was collecting insects for the Michigan Geological and Natural 

 History Survey. Through the courtesy of Dr. Alexander G. Ruthven, 

 Chief Field Naturr'ist of the Survey, I am enabled to give these notes in 

 advance of the full report. 



Up to the time these observations were made, I could obtain no 

 authentic records of any of these butterflies from Michigan, except of 

 i/orcas from the Lower Peninsula. But on this expedition definite data 

 were secured of tlie occurrence of all three in Dickinson County, in the 

 Upper Peninsula. From the lime of arrival of the party in the field 

 diligent search was made for both dorcas and epixanthe and their food- 

 plants, as it was particularly desired to add to the knowledge of the 

 distribution of these species in Michigan. 



The food-plant of dorcas., the shrubby cinquefoil ( Dasiphora fruti- 

 cosa), which I discovered in the summer of 1908, while making investiga- 

 tions upon this insect in the southern part of the State, was not found by 

 us in Dickinson County until the second of August. On this date a 

 member of the party brought in a spray of the plant from Waucedah, a 

 small town some sixteen miles south of Brown Lake. On the fourth of 

 August I was able to visit the locality, and found, just east of the railroad 

 station at Waucedah, many acres of the shrubby cinquefoil (locally called 

 "nine-bark"), (pi. IV, fig. i). It was very thrifty, the bushes being fine large 

 ones, and few having the dwarfed appearance of those often seen in Oakland 

 County, in the southern part of the State. In fact, in spots it fairly 

 crowded out all other vegetation. Notwithstanding the late date, the 

 imagoes of dorcas were abundant ; some of the males were worn and 

 gome in good shape, while all of the females observed, with one exception^ 



