On some South-American species of the 
genus Mydæa , parasitic on birds. 
By 
Dr. C, Nielsen. 
I. 
Iu 1911 I published a little paper: Mydæa anomala Jaenn,, 
a parasite of South-American birds 1 ) in which I described 
the three larval stages, the puparium and the imago of a dipterous 
insect, Mydæa anomala , which Mr. J. M o gens en had collected in 
December 1910—January 1911 in Concepcion, Argentina. The 
larvæ of the dy developed as subcutaneus parasites in tumors on 
various birds, both older and younger ones (Spermophila gutturalis, 
Mimus modulator, Homorus lophotes , Pitangus sulfuratus bolivianus). 
With regard to further details, as well as to the descriptions I 
may refer to my above cited paper, in which were also reproduced 
photographs of infested birds. The fly corresponded very well 
with the description of Mesembrina (Mydæa) anomala by F.Jaen- 
nicke ), I therefore did not hesitate in identifying the fly with 
that species. 
In 1912 I received from Mr. J. Mogensen a small collec- 
tion consisting of bred flies, puparia and third stage larvæ of a 
Mydæa- species which he had found parasitic on Xiphocolaptes 
albicollis in Bompland Missiones, Argentina. In letters to me Mr. 
9 In Videnskabelige Meddelelser fra den naturhistoriske Forening i 
København. Bd. 63. 1911. p. 195 . 
-) F. Jaennicke: Neue exotische Dipteren (Abhandl. herausgeg. v. d. 
Senckenbergischen naturf. Gesellschaft VI, 1866—67 p. 877). 
16 a* 
