ART. y TWO-WINGED FLIES OF TRIBE MILTOGKAMMINI ALLEN 23 



Length, 4.5 to 11 mm. 



Redescribed from a long series consisting largely of males in the 

 collections of the National Miisemn, the Miisemn of Comparative 

 Zoology at Cambridge, Massachusetts, Dr. C. W. Johnson, and the 

 writer from the following localities: Lafayette and Michigan City, 

 Indiana; Algonquin and Carlinsville, Illinois; Maryland; Tifton, 

 Georgia; Georgiana, Florida; West Point and Agricultural and 

 Mechanical College, Mississippi; Kansas; Cambridge, Nebraska; 

 Wild Horse Canyon, Animas, Santa Fe, and Socorro, New Mexico; 

 College Station, Balmorehea, and Galveston, Texas; Powdersville, 

 Montana; Los Angeles County, California; Havana, Cuba; one male, 

 Owen's Lake, California, labeled "on flowers of Asclepias" (J. M. 

 Aldrich) ; one male in the Loew collection bearing an orange label. 



The synonomy for this species has been submitted after a careful 

 study of Townsend's types loaned by the University of Kansas 

 Museum. The number of orbital bristles on the types of similis 

 and jlavicornis is variable, even as between the two sides of the 

 same specimen, varying from one to four. In the typical specimen 

 best represented by l-ansensis there are one reclinate and two pro- 

 clinate orbitals. 



It is not unusual to find specimens intermediate between typical 

 Jlavicornis and ruhriventris, which can not be very satisfactorily 

 placed. In the typical jlavicornis, the eye is more elongate, the 

 frontal row is more thickly beset with bristles, no median marginals 

 occur on the second segment of the abdomen, the hind tibia on the 

 outside is ciliate with a complete row of short bristles interrupted by 

 one long spine in the middle, and the specimens are usually larger in 

 size. 



Owing to the confusion that has long existed between this species 

 and ruhriventris, our knowledge of the geographical distribution is 

 limited. Specimens have been identified from Maryland, Indiana, 

 Illinois, Georgia, Florida, Mississippi, Kansas, Nebraska, New Mex- 

 ico, Texas, Montana, California, and Cuba. It has not as yet been 

 identified from the northeastern United States, Canada, or the Cen- 

 tral American countries. Nothing is known of the host relationships. 

 The writer found the adults abundant on the blossoms of Erigeron 

 in May in north central Mississippi, associated with *S'. trilineata. 

 Since then it has been collected occasionally on cowpea foliage in 

 the same locality. Dr. J. M. Aldrich reports collecting it from flowers 

 of Asclepias in California. I liave never encountered this species 

 resting on barren soil in the sunlight as do the other common species 

 of the genus. In collections, males far outnumber females, very 

 likely because the normal habitat of the mature female has not yet 

 been discovered. 



