ART. 20 



THE APHID GENUS AMPHOROPHOKA MASON 



43 



It is probable that Pergande referred to the intermediate when he 

 said "antennae dusky to black" as the second part of his description, 

 "'pale, the apex of jts. 3-5 and the 6th with spur black," seems to 

 apply better to the apterous forms. 



Intermediate. — ^The one specimen available (metatype specimen) 

 has antennae which are intermediate in color between the black 

 ones of the alates and the lighter ones of the apterous forms. Both 

 antennae are abortive, one having only a very short fifth segment and 

 no sixth, while the other has the fifth, base of sixth and a very short 

 unguis. Ill and IV are thickly covered with rather small sensoria. 

 V of the one antenna has six small inconspicuous sensoria. No 

 ocelli showing. Wings very small and abortive, about equally 

 developed on each side, hooks showing on both hind wings. Corni- 

 cles and Cauda appearing about as in the alate and apterous forms. 

 Measurements as follows: 



Oestlund reported this species as "very numerous on the upper 

 stalk and flower heads of Nahalus albus." Pergande took them on 

 the stem and under side of leaves. Miss Patch says it is not uncom- 

 mon in the east. 



The only dates recorded are September 28, 1897, at Zoological 

 Park, D. C, and July 11, 1903, at Minneapolis, Minn., both by 

 Pergande. 



Host. — Nahalus alhus. 



Distribution. — Minnesota, District of Columbia, Connecticut. 



i/etofype. ^Deposited in U. S. National Museum. 



AMPHOROPHORA NERVATA (GUlette) 



Figs. 130-138 



Rhopalosiphum nervatum Gillette, Canad. Ent., vol. 40, 1908, p. 63. — David- 

 son, Journ. Ec. Ent., vol. 7, 1914, p. 134.— Essig, Univ. Cal. Pub. Tech. 

 Bull. Agr. Exp. Sta. Ent., vol. 1, no. 7, 1917, p. 331.— Swain, Univ. Cal. 

 Pub. Tech. Bulls. Agr. Exp. Sta. Ent., vol. 3, no. 1, 1919, p. 84.— Patch, 

 Maine Agr. Exp. Sta. Bull. 282, 1919, p. 220. 



Rhopalosiphum arhuti Davidson, Journ. Econ. Ent., vol. 3, 1910, p. 378. — 

 EssiG, Univ. Cal. Pub. Tech. Bulls. Agr. Exp. Sta. Ent., vol. 1, no. 7, 

 1917, p.331. 



The writer has had the privilege of examining the cotype specimens 

 of nervatum Gill, from rose and of arhuti Davisdon from Arbutus and 

 considers them to be the same as has already been pointed out by 



