PSYCHE 
VOL. XXX. FEBRUARY 1923 
No. 1 
THE OCCURENCE OF MUSCINA PASCUORUM MEIGEN 
IN NORTH AMERICA IN 1922.^ 
(Presented Dec. 26, 1922, at the Boston meeting of the Entomological Society of America.) 
By Charles W. Johnson. 
Boston Society of Natural History. 
The increase and spread of this European fly in such num- 
bers and over so wide an area, before its presence was actually 
discovered, was a great surprise, especially to the dipterist. The 
first specimens to come under my observation were received on 
October 10, among some Diptera collected by Dr. W. M. Wheeler, 
at Colebrook, Connecticut. The three specimens were taken, 
August 10, 18 and 21. A few days later I received a box of flies 
from Mr. K. F. Chamberlain, of Cornwall Bridge, Conn., and 
among them was a specimen collected August 6, the earliest 
record I have for the species. Mr. R. T. Webber found among 
the material collected at the Bound Brook nurseries, N. J., a 
specimen taken September L Professor C. T. Brues observed it 
in numbers both in his house and about a neighboring cider mill 
at Petersham, Mass., October 8. Mr. F. H. Walker* collected 
two specimens at Marblehead, Mass., October 15. A few days 
later I received five specimens from Mrs. Ella L. Horr of the 
Worcester Natural History Society. Mrs. Horr said they were 
abundant in the cupola of the building and that the janitor said 
they were there in September, but that she did not happen to go 
there until about October 21. I wrote her that the fly was new 
to me and that I should like very much to have some more spe- 
cimens. No males had been seen and I was doubtful in which of 
two European species to place it. On October 25, Mrs. Horr 
wrote to me that she had sent some to Washington and on the 
26th sent me 51 specimens. I wrote to Dr. J. M. Aldrich in 
