214 APHIDS OF THE ROCKY MOUNTAIN REGION 
.13-.14; antenna .90; rostrum obtuse, attaining 2d coxa. Small Form. Body length 1.3-2; hind 
tibia .40-.65; antenna .50-.60; rostral IV-+V .09. 
Alate Vivipara. Head and thorax blackish; abdomen pale yellowish brown; appendages, 
cauda and cornicle dusky to blackish. Body length 1.3-1.5; hind tibia .90-1; hind tarsal II 
.13-.15; antenna 1.15-1.50, secondary sensoria strongly convex; rostrum hardly attaining 2d 
coxa. Hairs pointed, sparse; .02-.03 on tibia. Cornicle clavate, at middle nearly twice as wide 
as tibia, transversely rugose proximally, otherwise smooth, with flange. Cauda tapering, 
acute, bearing 2 pairs of lateral and 1 pair of dorsal hairs. 
Ovipara. Apterous. Pale yellowish with head brownish; appendages, cornicle and cauda 
pale to slightly dusky. Body length .85-1.15; antenna .40, III and IV coalesced; cauda .10 on 
median line, .14 on side. Hind tibia strongly swollen on nearly entire length and bearing 
numerous rather large sensoria. 
Male. Alate. Color same as summer alate vivipara or slightly darker and size slightly 
smaller. 
Egg. Newly laid, pale greenish yellow; later, black. Size .51 by .22. 
Collections. On leaves of Lonicera sp., Xylosteum sp. and Symphoricarpos 
sp. as winter hosts; dill (Anethum graveolens), celery (Apium graveolens), Ber- 
ula erecta, Cicuta sp., Conium maculatum, carrot (Daucus carota), Heracleum 
lanatum and parsnip (Pastinaca sativa) as summer hosts. Throughout region. 
Fundatrices May 11 t> 26, apterous and alate summer viviparae June 3 to June 
30 and Nov. 15 on winter host, June 19 to Sept. 10 on summer host; sexuales 
Nov. 7 to 12 on winter host, males also on summer host Sept. 27; rather common. 
Type. Location unknown. Metatypes, Essig Collection. 
Chief Distinguishing Characters. Absence of precaudal dorsal tubercle and 
presence of secondary sensoria on IV of alate vivipara. 
Rhopalosiphum enigmae Hottes and Frison 
Rhopalosiphum enigmae Hottes and Frison, 1931a:235; Gillette and Palmer, 1932b:482. 
Apterous Summer Vivipara. Yellowish or greenish to reddish-brown or bronzy black, 
often with rusty blotch at base of each cornicle; cornicle black; antenna, cauda and legs 
brown, darker distally. Body length 2-2.4; hind tibia .90-1; hind tarsal II .14; antenna 
1.05-1.30. 
) 
) 
ees 
13-14 
Fig. 251. Rhopalosiphum enigmae 
Alate Vivipara. Head and thorax dark dusky brown; abdomen yellowish or reddish 
brown; antenna dark, lighter on base of III and unguis; cornicle, cauda and anal plate dark; 
tibiae yellowish brown with tip dark brown; tarsi blackish. Body length 1.80; hind tibia 
.95-1; antenna 1.35; cornicle distinctly wider than hind tibia; rostrum obtuse, attaining 2d 
coxa more or less. Frontal tubercles considerably developed, slightly exceeding vertex. Hairs 
pointed; .05-.07 on tibia; rather numerous. Cornicle slightly incrassate, suddenly constricted 
just before wide flange, slightly imbricated. Cauda parallel-sided, obtuse, bearing 2 hairs on 
each side. Lateral tubercles present but small. Fore wing with 2d fork of media very short, 
hardly a fifth the distance from margin of wing to Ist fork. 
Ovipara. Apterous. Reddish-brown, lighter anteriorly and posteriorly; tibiae pale except 
tips; antenna and cornicle dark; cauda pale. Body length 2; antenna 1.16; with hind tibia 
.75-.85 long, moderately swollen for almost entire length and bearing numerous large sensoria. 
Male. Alate. Color same as alate vivipara. Body length 1.66; antenna 1.50-1.60, III, IV 
and V bearing numerous sensoria. 
Egg. Newly laid, pale yellowish; later, black; shining. Size .70 by .30. 
