JULY, 1900. GRAENICHER— THE SYRPHIDAE OF MILWAUKEE COUNTY. 167 
The Syrphidae of Milwaukee County* 
By Dr. S. GRAENICHER. 
Of all the insects visiting flowers in search of honey and pollen, 
none are more apt to attract the attention of the observer, than 
the flies belonging to the family of Syrphidae. The}^ display an 
elegance of form and markings, and a gracefulness in their move- 
ments, when on the wing, which rarely fail to win our admiration. 
As agents in transferring pollen from one flower to another, and 
thereby efifecting cross-fertilization, they are of the utmost impor- 
tance. Some of the species are represented by great numbers 
of individuals, and may, in our latitude, be observed as flower- 
visitors from the beginning of April to the later part of October. 
The species which never resort to flowers are few in number. 
During the past five years, while studying the mutual relations 
of flowers and insects, I have become acquainted with 64 species 
of Syrphidae, occurring within the limits of Milwaukee county, 
few of which have hitherto been recorded from the State of Wis- 
consin. In the following I present a list of these species, and 
accompany the name of each with a few remarks, pertaining to 
the time of flight, the geographical distribution of the species and 
the flowers visited by the insect at the date of capture referred to : 
1. Microdon tristis, Loew. Rare. 3 '-'specimens taken in 
June, flying along ^dry, sunny paths, near the ground. 
I have never observed this species as a flower-visitor. 
Previously reported for the Atlantic States, Oregon 
and the Mackenzie, River. 
2. Paragus bicolor. Fabr. Not common. From May (on 
flowers of Mitclla diphyUa, L.) to September (on flowers 
of Aster lateriflorus (L.) Britt)- Occurs in Europe and 
North America. Has been recorded from Connecticut, 
Washington, Montana southward to New Mexico, and 
also from Illinois. 
3. Paragus tibialis^ Fallen. Not commoner than the preceding. 
Fron May (on flowers of Veronica scrpylli folia, L.) to 
October (on flowers of Eupatoriiim ageratoides, L.). 
Inhabits Furope and North America and has been 
recorded from the New Fngland States, California, New 
Mexico and Illinois. 
(^) J" Male ? Female 
