98 Annals Entomological Society of America [Vol.11, 



pletely atrophied. Cornicles (Figs. 9, 13), never swollen, but broad 

 at base tapering gradually to apex, distinctly imbricated, black, about 

 1.5 times length of hind tarsus. Cauda (Fig. 14), stouter, apex more 

 rounded, beset with many stout curved setae, bicolored, the basal half 

 between the black margins being pale yellowish, while the distal half 

 is dusky to blackish. The prothoracic and 2nd and last abdominal 

 tubercles very pronounced, longer than broad. 



Measurements. Length of body, 2 mm. width .98; antennae 

 1.25; wing 2.75; cornicles, .20; cauda, 1.5 (averages from several 

 specimens.) 



The life history of this black aphid is different from the 

 green species. It never forms galls, usually infests the under 

 side of the leaves or the inflorescence in summer as well as fall, 

 attacks Rttmex and other weeds besides the ChenopodiacecE; and 

 migrates in the fall from these plants to the wahoo (Euonymus 

 atropurpiirea.) I observed this migration to the wahoo last fall 

 at Forest Hills w^here the so-called sexuparse were depositing ovi- 

 parous larvae on the under side of the leaves. These true mi- 

 grants were precisely identical in structure with the winged \-i\'i- 

 parse on Cheno podium. 



Osborn established the migration of this w^ahoo aphid (Aphis 

 rvimicis ? L. = A. euonymi Fab.) in Iowa in 1894. Either this 

 species or a closely similar one migrates between the same hosts 

 in Europe. 



It is my privilege to acknowledge Professor Wheeler's kind 

 criticisms in the preparation of this article. 



LITERATURE 



Aphis atriplicis Fab., Fabricius, Syst. Ent., 1775, p. 737, No. 21, is a distinct 



species belonging to the Aphis i-uniicis group. 

 Aphis atripUcis L., Linnicus, Fauna Svecica (ed. altera), 1761, p. 262, No. 1000. 



Original description. Sweden. Atriplex littoralis. 

 = chenopodii Schr., Schrank, Fauna Boica, Vol.2, Pt. 1, 1801, p. 109, No. 



1196. Bavaria, Atriplex patula; descriptions of winged and wingless 



viviparae. 

 Kaltenbach, J. H., ]\Ionogr. d. Pflanzenl., 1843, pp. 107-108. Germany. Cheno- 



])odium album, Atriplex patula. Descriptions of winged and wingless 



viviparae. 

 Passerini, G., Gli Afidi, 1860, p. 31. Italy. 



lb. Flora degH Afidi Ital., in Bull. Ent. vSoc. Ital. 3, 1871, pp. 151, 155. 



On Atriplex patula and Chenopodium album. 

 Kaltenbach, J. H., Ptianzenfeinde, 1874, pp. 505, 508. In German^-. Same 



hosts and habits. Sometimes affects all the leaves of the plants mak- 

 ing the leaves appear yellowed and sickly. 

 Buckton, G. B., British Aphides, Vol. 2, 1879, pp. 87-90, col, pi. 65, figs. 4-7. 



All descriptions and figures apply to an insect of the Aphis rvmiicis type 



except possibly the wingless inalc and the ovipara which apparently 



belong to Aphis atriplis L. Notes on the galls and oviposition in the 



galls. Atriplex sp. England. 

 Monell, J., Bull. U. S. Geol. & Geogr. Surv. Terr. Vol. 5, No. 1, 1879, p. 25. 



Common on Chenopoditims at St. Louis, Mo., and at Carbondale, 111. 



(Thomas, C. 8th report Ins. 111., 1879, p. 193.) 



