18 BULLETIN 826, TJ. S. DEPARTMENT OE AGRICULTURE. 
very large, one of the largest aphids. Del Guercio set no type 
for his subgenus which was published shortly after Wilson's. 
Wilson placed this species as a synonym of caryae Harris which he 
made the type of Longistigma. 
Characters. — Size large. Head somewhat divided. Eyes large, with distinct 
ocular tubercles. Antennae of six segments, armed with subcircular sensoria and 
prominent hairs. Fore wings with media twice branched, radial sector not a great way 
from the tip of wing and stigma extending around almost to tip; hind wings with both 
media and cubitus present. Cornicles on broad, shallow, hairy cones. Cauda and anal 
plate somewhat rounded. 
O vdparous female apterous. Males winged. 
Type (monotypical), Aphis caryae Harris. 
Genus PTEROCHLORUS Rondani. 
Plate II, S-X. 
1848. PterocMorus Rondani, "Familia Hemipterorum Aphidio.se'! in Nuovi Annali delle Scienze 
Naturali, p. 35. 
1855. Dryobius Koch, Die Pflanzenlause Aphiden, p. 225. 
1908. Tuberolachnus MordVilko, Ann. Mus. Zool. de TAcad. Imp. des Sci. St. Petersbourg, v. 13, 
p. 374. 
1909. Dryaphis Del Guercio, Redia, v. 5, p. 262. 
1913. ScMzodryobius Van der Goot, Tidj. voor Ent., v. 56, p. 130. 
1917. Pterochlorides Archangelsky, Turkestan Ent. Stn. Rept. Tashkent. 
1918. Tuberodryobius Das, Mem. Ind. Mus., v. 6, p. 259. 
The generic name Cinaria was used for Aphis pini L ?, and Aphis 
roboris L. with A. pini as type. In the writer's opinion Cinaria can 
not be used now with roboris as type. Roboris was used as the type 
of Dryobius, therefore this name is clear. Dryaphis was used with 
Pterochlorus as a synonym but the name as a generic name was really 
first used by Del Guercio in 1909. Tuberolachnus was erected in 
1908 with viminalis Boyer as type but the difference in the abdominal 
tubercle is not, in the writer's opinion, sufficient for a distinction. 
Van der Goot's genus is plainly a synonym. The other two generic 
names listed were used with Lachnus persicae Choi, as type. This 
species has several abdominal dorsal tubercles but for the same reason 
as Tuberolachnus is held to be a synonym. 
Characters. — Head somewhat rounded. Antennae of six segments, armed with 
subcircular sensoria and prominent hairs. Fore wings with radial sector distinctly 
curved, inserted some distance from tip; media twice branched. Hind wings with 
both media and cubit as present. Wings often banded or mottled, cornicles on hairy 
cones. Cauda and anal plate rounded. Abdomen sometimes with dorsal tubercles. 
Type (fixed by Rondani, 1848), Aphis roboris Fab. (=roboris L.). 
Genus STOMAPHIS Walker. 
Plate II, M-R. 
1870. Stomaphis Walker, The Zoologist, v. 28, p. 2000. 
1881. Rhynchocles Altum, Forst Zool., v. 3, p. 356. 
Of the five species originally in the genus Lachnus the species 
quercus Linn, was removed by Walker as the type of his genus Stoma- 
phis. Little confusion has arisen in regard to this species. Al turn's 
genus was erected for Rhynchocles longirostris* 
