66 BULLETIN" 826 ; U. S. DEPARTMENT OF AGRICULTURE. 



Genus COLOPHA Monell. 

 Plate IX, G-L. 

 1877. Colopha Monell, Cau. Ent., v. 9, p. 102. 



The genus Colopha was erected for ulmicola Fitch. One of the 

 principal characters whereby it may be separated from Tetraneura 

 is the once-branched character of the media. The two genera, how- 

 ever, are very closely related. The species have the same peculiar 

 structure and the same mode of life. 



Characters. — Cornicles slightly elevated rings. Stem mother with four-segmented 

 antennse. Apterous form with five-segmented or sometimes six-segmented antennae. 

 Wax glands present. Alate form with six-segmented antenna? which are armed with 

 annular sensoria partly encircling the segments. Fore wings with the media once 

 branched, hind wings with only the media present. Forms making galls upon the 

 leaves of trees in which the stem mother and her offspring live in company; in summer 

 migrating to the roots of plants. 



Type (monotypical), Byrsocrypta ulmicola Fitch. 



Genus ERIOSOMA Leach. 



Plate IX, M-T. 



1818. Eriosoma Leach, Trans. Hort. Soc. London, v. 3, p. 60. 



1831. Myzoxylus Blot, Mem. Soc. Roy. Agr. et de Coin. Caen., v. 3, p. 332. 



1837. ScMzoneura Hartig, Jahresb. ii. d. Fortschr. d. Forstwiss. und forstl. Naturk., v. 1, p. 645. 



1848. Mimaphidus Rondani, Nuovi Annali della Scienze Naturali, ser. 2, v. 9, p. 35. 



In 1818 Leach erected his genus in a footnote in connection with a 

 paper read by Mosley. The paper was published in 1818. In 1819 

 Samouelle published his "Useful Compendium" and on page 232 

 characterized the genus Eriosoma Leach MSS. The printed copy 

 of the Transactions appeared complete in 1820. In 1824 Blot used 

 the word Myzoxyle which he corrected to Myzoxylus in 1831. For 

 these ApTiis lanigera Hausm. was used as type. 



In 1837 Hartig erected Schizoneura and of this genus ulmi was made 

 type by Passerini in 1860. This then will become a synonym. 

 Corni Fab. was for a time considered the type of this genus but this 

 species was not in the original genus. In 1848 Rondani used Mima- 

 phidus with ulmi Fab. as type, which according to Passerini is the 

 same as lanuginosa Hartig. Therefore, this genus will become a 

 synonym. 



Characters. — Cornicles distinct rings on somewhat elevated tubercles. Apterous 

 form with six-segmented antennse. Stem mother with five-segmented antennse. 

 Wax plates present in the apterous and alate vivipara. Alate form with six-seg- 

 mented antennas armed with annular sensoria. Fore winga with the media once 

 branched, hind wings with both media and cubitus present; cauda and anal plate 

 rounded. Forms living in gall-like formations or causing excrescences on their hosts. 

 Sexual forms small, apterous, beakless. Only one egg of those of the oviparous female 

 develops. 



Type (monotypical), Aphis lanigera Hausmann. 



