THE CANADIAN ENTOMOLOGIST. 103 



SYNOPSIS OF THE DIPTEROUS GENUS PHORA. 



BY D. W. COQUILLETT, WASHINGTON, D. C. 



In Osten Sacken's well-known Catalogue of Diptera ten species of 

 Phora are credited to our fauna. Of these I have been unable to find 

 any Phorid described by Fabricins under the name of atra. The author 

 who first used this name appears to have been Meigen ; in his Klass. 

 Besch. Eur. Zwei. Insect (1804), this author describes a Trineura atra, 

 but in his later work (Syst. Besch. Eur. Zwei. Insect, 1830) this name is 

 relegated as a synonym of Musca aterrima, Fabr. (Ent. Syst., 1798). In 

 the recent revision of the Austrian Phoridae, by Strobl (Wiener Ent. 

 Zeitung, 1892, pp. 193-204), no mention is made of a Phora atra, Fabr. 

 The reference in the Catalogue should therefore be credited to Meigen, 

 and transferred as a synonym of Tririeura aterrima, Fabr. 



Phora fuscipes, Macq., has been credited to our fauna by Walker, 

 but from Macquart's three-line description it is quite impossible to iden- 

 tify the species, and the name should therefore disappear from our list. 

 The form doubtfully referred to this species by Zetterstedt does not 

 occur in our fauna so far as I am aware. 



Since the publication of the above mentioned Catalogue, descrip- 

 tions of five supposed new species of Phora from our fauna have been 

 published, viz.: aletice, Comstock (Cotton Insects, 1879, pp. 208-211), 

 and four other species by Prof. Aldrich, in the Canadian Entomologist, 

 Vol. XXIV., pages 142-146. Although I have not seen an undoubted type 

 of Phora aletice, Comst., still there is every reason for believing that it is 

 identical with the common Phora nigriceps, Loew. The described female 

 was evidently immature, which would account for the darker markings 

 on the abdomen mentioned in the description ; in the male, however, it 



is stated that the " dorsal portion of the abdomen is entirely blackish," 

 and this accords perfectly with the colouring of this part of the body in 

 normally coloured specimens of nigriceps. Moreover, this latter species 

 has been repeatedly reared from larvae feeding upon the decomposing 

 chrysalides of x\letia, thus having similar habits to the form described by 

 Prof. Comstock. 



So far as at present known, the larvre of all the different species of 

 Phora feed upon animal or vegetable substances in a more or less state 

 of decay. In Prof Aldrich's paper mentioned above the statement is 

 made that several of the species were reared from Cimbex cocoons, 

 but in a recent letter the author states his conviction that these cocoons 

 contained only dead larvae and pupae at the time they were attacked by 

 the Phorids. 



