SUBFAMILY ERIOSOMATINAE 353 
gerum and by Heriot (1938:Feb. 16) to be E. crataegi (Oestlund). Cox (1939:477) 
however reports elm leaf-cluster aphid transfer attempts to Crataegus to have 
been unsuccessful. 
Failure to establish evidence of migration between elm and apple has been 
reported by workers in nearly all parts of the world; namely, Simms (1927) in 
Poland, Marchal (1928:1) in France and Hori (1930:35) in Japan. As far as is 
known to the writer this species has not been traced through the complete life 
cycle from apple to the developed leaf cluster and back to the apple by anyone. 
Eriosoma rileyi (Thomas) 
The Woolly Aphid of the Elm Bark 
Eriosoma ulmi Riley, 1869:123 (preoccupied). 
Eriosoma rilepi Thomas, 1876 (1877) :191 (lapsus calami for rileyi new name for Erio- 
soma ulmi Riley). 
Eriosoma rileyi, Patch, 1910b:235 and 1913b:260; Hottes and Frison, 1931a:354: Gil- 
lette and Palmer, 1934:212. 
Fundatrix. Dark chestnut-brown, dusky on head, lighter on thorax and venter (much 
lighter when mounted in alcohol); cottony; appendages dusky. Size 2.25 by 1.60; antenna .35; 
hind tibia .30. Cornicle not apparent. Young. Deep pink. 
Apterous Summer Vivipara. Light flesh color with antenna same as body; powdery. 
Body length. 2; hind tibia .53-.55; hind tarsal II .13; antenna .45-.54; rostrum attaining be- 
tween 2d and 3d coxae. 
Fundlatrix 
Cea 
Cad =ra) ~~ FOS eg04, 22) 
Glands 
Eye 
<@ 
C09 - a (= 4D 
5 Mos 06) 02 es v9 "6 
” Fi ig. 423. Eriosoma rileyi 
Alate Vivipara. Head and thorax black; abdomen slightly lighter; more or less powdery; 
appendages black. Body length 2.25; across eyes .43; hind tibia .70; hind tarsal II .14; fore 
wing 3.1; antenna .77-.84; cornicle pore .03-.04 in diameter. 
Apterous Sexupara. Dull yellow-brown; woolly; cornicle and appendages dusky brown. 
Body length 1.75; antenna .63, five- or six-segmented; hind tibia .35. 
Ovipara. Apterous. Light yellowish; with little tufts of secretion on dorsum. Body 
length .73-.80; antenna .17-.19; five-segmented, III+IV .035, V .045, VI .04+-.02; hind tibia 
.13; hind tarsal II .05; rostrum lacking; cornicle not apparent. 
Male. Apterous. Greenish yellow; with cottony tufts. Body length about .50; antenna 
.17. Rostrum missing; cornicle not apparent. 
Egg. Newly laid, yellow to dusky brown. Size .45-.50 by .22-.25. Laid singly beneath 
scales of bark. 
Collections. On bark of trunk and roots near crown of Ulmus americana, 
not producing galls. Colorado: Sterling, Fruita, Rocky Ford, Denver and Fort — 
Collins. Fundatrices May 24 to 31, apterous and alate summer viviparae June 13 
to July 24 and Sept. 4 to Oct. 12, apterous sexuparae Oct. 2, sexuales Oct. 23 to 
29, rather common at times. 
This species is distinguished from E. americanum and E. lanigerum by the 
shorter antenna of the fundatrix and the narrower secondary sensoria with 
wider intervening spaces in the alate vivipara. - 
Genus Gobaishia Matsumura 
Matsumura, 1917:75; Baker, 1920a:67; Maxson, 1923:316. 
Characters. Antenna four-segmented in fundatrix, six-segmented in sum- 
mer viviparae; secondary sensoria in alate vivipara annular. Tarsi two-seg- 
mented. Media of fore wing once-forked or simple; hind wing with both media 
