352 APHIDS OF THE ROCKY MOUNTAIN REGION 
Collections. On apple (Malus sp.), on twigs, roots causing galls, but espe- 
cially on bark, in crevices of swellings caused by their feeding. Throughout re- 
gion. Apterous summer vivparae all months of the years (hiberating viviparae 
during the fall and winter), alate viviparae June 20 and Aug. 22 to Oct. 29 
(especially numerous during September), sexuales Sept. 6 to 26 (obtained only 
by confining fall migrants leaving apple); very common and often injurious. 
Chief Distinguishing Characters. Reddish brown body and blood-red stain 
when crushed, fluffy flocculent covering of secretion, number of sensoria on VI 
of alate vivipara (2-3), small size of cornicle pore (.06-.07 in diameter in aptera, 
.05 in alata) and the habit of feeding on bark and roots and pore gall growth 
on roots and swelling on bark. 
Though the eggs are considered by Patch (1913b:264 and 1916:330), Baker 
(1915:1), Becker (1918:3), Maxson (1915:367) and Schoene and Underhill (1934:1) 
to be laid on elm, elm is not necessary for the existence of this aphid as they 
commonly hibernate on the apple in the apterous viviparous state. In some 
heavily infested sections of the western part of Colorado elm leaf-cluster galls 
have been rare or unknown, during the thirty-year period of observations by 
workers here. This species is reported as existing independent of the elm in 
continental Europe by Marchal (1928:1), in Japan by Hori (1930:35) and in Po- 
land by Simms (1927) and in Canada by Heriot (op. cit.). 
On elm: 
Fundatrix. Young Adult. Sordid yellowish brown or cinnamon-brown, with head, pro- 
thorax, tip of abdomen, and appendages including coxae dusky to black; venter lighter; 
dorsum heavily covered with flocculence. Older Adult. Dark slaty, almost black; head, and 
appendages black. Body length 2-2.6; hind tibia .36-.40; antenna .46-.55; rostrum attaining 2d 
or 3d coxa. 
: (37- 46) 
cee 
Fig. 422. Eriosoma lanigerum on elm 
) Ta Cis, 
Al=Apt. 
Apterous Summer Vivipara. (Second generation). Young. Newborn, very pale yellow 
with head dusky; appendages slightly dusky, nearly transparent; dorsum soon becoming cov- 
ered with flocculence. After feeding, light rusty brown. Adult. Pink with head and posterior 
end of abdomen somewhat dusky; antenna dusky; entire body heavily covered with floccu- 
lence. Body length 2.5; antenna .82-1; hind tibia .75; rostral IV+V .20, attaining 2d coxa. 
Cornicle mere ring .06-.07 in diameter with chitinized bow on medioanterior side and on 
slightly raised base which bears scattered short hairs. A few apterae present in this genera- 
tion but the great majority are alatae. 
Alate Vivipara. Head and thorax blackish brown; prothorax and abdomen yellowish 
brown to rusty brown; covered with flocculence; appendages, rostrum, cornicle, cauda and 
anal plate dusky. Body length 2.2; antenna .82-1; hind tibia .75-.86; rostrum attaining be- 
tween Ist and 2d coxae. Cornicle pore .05-.06 in diameter. 
Collections. On Ulmus americana, in curled terminal leaf-clusters. Colo- 
rado: Longmont, Kiowa, Castle Rock and Fort Collins. Fundatrices Apr. 23 to 
June 20, apterous and alate summer viviparae May 13 to July 25, elm deserted 
after July; not very common. 
Type. U.S.N.M., No. 59324. Paratypes, Colo. Agr. Exp. Sta. Collection. 
This species is considered by Patch (1913b:264 and 1916:329), Baker (1915:1), 
Becker (1918:3) and Maxson (1915:367) to migrate to apple and to be E. lani- 
