APHIDS INFESTING ECONOMIC PLANTS 399 
BB.—Cauda short wartlike, tapering; cornicle not shorter than III and not short- 
er*than unguis>)Sensoria 19 to°30 on IIT in alata.. (0.0174) occccoccccoccccecccccseschceceseeseecesee 
eR CE as i Ect Uitte The Elder Aphid (Aphis sambucifoliae) 
AA.—Antenna longer than body; frontal tubercles well developed, exceeding vertex. 
B.—Body 3 to 4 long; cornicle somewhat swollen near distal end, reticulated at 
tip; cauda with 5 hairs on each side; rostral IV-+-V same length as hind tarsal II. 
pepe 4 Scere ee ee ee The Large Elderberry Aphid (Amphorophora stanleyi) 
BB.—Body 1.5 to 2 long; cornicle not swollen and not reticulated; cauda with 
only 2 or 3 hairs on each side; rostral IV-+V shorter than hind tarsal II. (p. 314) 
Sept eh enki he OL aS AS senha a TA) a Mclie: SN Ae nee rele Macrosiphum macrosiphum 
Elm, American (Ulmus americana) 
A.—Living on bark. Body woolly, dull yellow and brown; sluggish; fore wing with 
media once-branded; antenna short, one-fourth to one-third of body length; sensoria 
of antenna annular; 13-23 on III, 2-4 on VI; rostral IV+V .18 in alata. (p. 353)........ 
a5 fella dita WS) al I Seat Poa RB daa The Woolly Aphid of the Elm Bark (Eriosoma rileyi) 
AA.—Living on leaves. 
B.—Not deforming leaves or causing galls. Sensoria circular to oblong; 6-10 on 
III; legs half length of body; body naked; media of fore wing twice-forked; an- 
Mmamong neatly equal to .pody.( ps7 S)ic. eee ee ee 
Spt 18 ne ee AE BULLE oy eae an oe Ree ete ape, Ree The Elm Leaf Aphid (Myzocallis ulmifolii) 
BB.—Deforming leaves or forming galls. Sensoria on antenna annular; legs 
short, not exceeding third of body; body woolly; media of fore wing once- 
branched or simple; antenna shorter than half body. 
C.—Forming cockscomb galls on upperside of leaves. Body green to brown or 
black; fore wing with media simple or once-branched; sensoria broken, 9 to 
a oTOn EE ison. V1. rostral. V-+-V,.07 long. (p. 347)... en Colopha ulmicola 
CC.—Causing leaf pseudo galls. 
D.—One side of leaf rolled under. Aphids woolly; dark green to black; 
fore wing with media once-branched; antenna of alata equal to half body 
length; sensoria 23 to 27 on III, 0 on VI; rostral IV+V .16 to .19 in 
alata a( P0949) set esto t The Woolly Elm Aphid (Eriosoma americanum) 
DD.—Rosettelike clustering of leaves on twigs. Aphids woolly; pinkish 
to reddish brown; fore wing with media once-branched; antenna one- 
fourth to one-third length of body; sensoria 37 to 46 on III, 0 on VI; 
COSCLAI LV ct Ves e OatOnel Oalitial a tase per SOE) cece eee ec cn ee ae re ec cast eset c eee 
SA ah ON. Se SE The Woolly Apple Aphid (Eriosoma pts 
Elm, Camperdown (Ulmus campestris) 
Forming globular or egg-shaped galls attached by pedicel to upper surface of leaf. 
Aphids slightly powdery; ochre to pinkish cinnamon to dark green; fore wing with 
media once-branched; antenna short, about one-fifth of body length; sensoria annular 
10 to 19 on III, 1 on VI; rostral IV+V .15; tarsal I and II not distinctly separated. 
(Gay SEE CY ERs ae En to i te he Sid A APR nia Ra Re eee ky aed A Colopha ulmisacculi 
Elm, Red (Ulmus fulva) 
Forming pouchlike spindle-shaped galls on upperside of leaves; fore wing with media 
simple or once-forked; antenna short, third to half of body length; sensoria annular, 
17 to 20 on IIT;’6 to 10 on V1; rostral IV-+-V .08. (p. 354) —--2.--..----.-.1020-. Gobaishia ulmifusa 
Engelmann Spruce—see Spruce 
Fir, Alpine (Abies lasiocarpa) and White (A. concolor). On twigs. 
A.—Sensoria oval-transverse; cornicle a mere ring; hairs inconspicuous; stigma 
reaching tip of wing; body pale yellow, appendages pale. (p. 346).....----------.:--::e--eseeeeee-* 
i Re SOS ge EL Or OR Oe ian Fs Be ee a The Balsam Twig Aphid (Mindarus abietinus) 
AA.—Sensoria circular; cornicle mammiform, hairy; hairs on body and appendages 
more or less conspicuous; stigma not reaching tip of wing. 
B.—Hairs on antenna and hind tibia usually blunt, shorter than diameter of tibia, 
especially in alata; body 5 long; hind tibia 3.5 to 4.6; rostral IV .25; body 
brownish black, with little pulverulence; legs dark. (p. 28)........-..---.:ccssceseseeeeeeeeeeeeees 
Te Ta See CRE LOE LS RL) Arte Oy mene ee The Bow-legged Fir Aphid (Cinara curvipes) 
BB.—Hairs on antenna and hind tibia long and pointed, longer than diameter of 
tibia. 
C.—Body 4 to 5 long; hind tibia 3.5; rostral IV .25; hairs on hind tibia about 
1 to 1.5 times as long as diameter of tibia; body reddish to dark brown, mot- 
tled with white pulverulence; legs almost entirely black. (p. 34)..........-....--.----- 
The Spotted Alpine Fir Aphid (Cinara lasiocarpae) 
