32. 
33. 
40. 
41. 
42. 
43, 
44, 
45. 
46. 
47, 
48. 
49. 
50. 
syle 
APHIDS OF THE ROCKY MOUNTAIN REGION 
Unguis barely shorter than 1.5 times length of V. (p. 140)....22....-.22222-:::seeeeeeeeeeees gutierreziae 
Unguis longer than.1.5 times length of Vi ~.cc2-2, cinc-sccpacsben.ccecstereneengaoseenr a7 seers 27 
Hind® tibia vLeme-t hiys7.0=.8 058 Cres USD) cee ee nee i aera eae er maidi-radicis 
Hind»tibia length®;60=<70.) Gp. 5 180) a ce ace ee ee ee tetradymia 
Hairs reclinate;enot mumeroius. epee) se eee he eee se armoraciae 
Hairs erect and numerous; cornicle 1-1.5 times rostral IV+V (p. 146).................. knowltoni 
Hairs as above; cornicle 2-4 times rostral IV+V (p. 174).....-2..:0.e:-cceeeeseeeeeeeeee sambucifoliae 
Hatrsiminute:, (p?.120) 22-2 ee Sr Sere ee chipetae 
Hairs:prominent: (px 184) 02 eRe ee eae ae ee viburnicola 
Cornicle shorter than 1:5 times base of [VTi c.22ec2o2o occas eee 31 
Cornicle at least 155. times asslong as baseiof VD sie ieee oceans eee 38 
Imbrications on cornicle plainly denticuliate 22sec cccccece cers - cote ees -eee ce nee ee 32 
Imbrications on cornicle not evidently denticulat eo ecccsccccccececee-oee eee eee 34 
Rostral IV+V .10, not longer than cornicle, attaining 2d coxa. (p. 124)............2......- baker 
Rostral IV+V .12-.15 long, longer than cornicle, surpassing 2d COxa........02..---.2::c-sseceseeeee--* 33 
Unguis not distinctly slonger tian) Viqmp aia: 2 2)) peer ae argentinae-radicis 
Unguis 1.6 times to twice as long as IV; alata with dorsal black patch 
on abdomen: > (piwl46)isse ane cee ge ee ee ee kachena 
Unguis 1.5 times as long as IV; alata without dorsal black patch 
onsabdomense-( piss 13:2.) a rr er ee crataegifoliae 
Cauda’ bearing ‘2-3 hairs’ on. each; sid @)2:.2-t-4458-2 ee eee ee 87 
Cauda bearing at least’4 hairs on each side 222 2--22..-20 ee 35 
Antenna of alata with more than 20 sensoria on III. (p. 155) ...2.......ccceececeeceeeeeeeeeeeeeee neilliae 
Antenna of alata with not more than 10 sensoria on Ill —.2...2.2... 36 
Cornicle: withflange., (p.133)2 2.2 ak eee eee crypta 
Cornicle: without. flamge) <2228 seco occ secee cea Nees 37 
Color of body pink with dusky bands; unguis longer than cornicle. (p. 160)................ ornata 
Color of body green with dusky bands; unguis equalling cornicle. (p. 140).............. gregalis 
Color of body black with dark bands (evident after clearing) ; unguis hardly 
longerithan.cornicle:” (ps157) Gee ee ee ee ee eee nigra-gregalis 
Frontal tubercles slightly exceeding vertex; cornicle curved or-slightly clavate.............. 39 
Frontal tubercles not exceeding vertex: cornicle straight 222-2 40 
Hairs’ capitate. < (ps, 1.69 )¥ seven se 3. Ne i eae ee rosea 
Hairs ‘pointed: (pz 186) Sota ee ee ee eee eee es vorabonnevilla 
Cornicle not longer than: 125 times) hind tarsal lie) ee "5, noes 41 
Cornicle longer than 1.5 times hind tarsal ll =... eee 42 
Sensoria on III of alata fewer than 10; unguis 1-1.3 times rostral 
TV =E Vs. “Gp 133) icchiccccce teed, Be ee ee ee oe Seg crypta 
Sensoria on III of alata more than 10; unguis 2-3 times as long as rostral 
EVAR V $2 (ps LRT) Fie ices cece RE A ee ac ge eae ee a tulipae 
As above except unguis 1-1.5 times rostral IV+V. (p. 186) -.-..----........:c2---ccc-eeeneeesceeeees zonassa 
Cauda shorter.than half of base Of VD 2.c.qcccutee Soca oss eee 48 
Cauda‘at least half as-long as, base of WI2. .22:22-...2-- ene 43 
Cornicle shorter than unguis; body green with dusky markings. (p. 127).......2.......---.- cardul 
Cornicle longer than unguis body brown) and. black so. 5.2. 88 
Cauda tapering, €nding jin a ‘potmti: xe one nase eee eee 45 
Cauda notstapering, tip rovirid CC ocean eee 54 
Cauda bearing 6 or more pairs of Nairs --22cicc-cceccceeeccceeceeccne etn eehsge snd Jetacacedede serene 46 
Cauda with fewer than 6 pairs of hairs; cauda not longer than base of VI..............--..-.-------- 50 
Cauda shorter than base of VI; cornicle longer than hind tarsus. (p. 132)................ cowenl 
Cauda shorter than base of VI; cornicle shorter than hind tarsus. (p. 133)........ debilicornis 
Cauda longerithan base Of VL ce fe sence ae ne ee once eee ae ne 47 
Cornicle shorter than 3 times length of base of VI, same length as unguis. (p. 148)-....Jupini 
Cornicle 3-4 times as long as base of VI, longer than ungulsS..............22...2.:0:cccsseceeeeeeeeeeneeeeene 49 
Rostral IV+V hardly longer than hind tarsal II; body black. (p. 162)........ persicae-niger 
Rostral IV-+V longer than 1.5 times hind tarsal II; body green. (p. 181)....unaweepiensis 
Unguis shorter than 3 times base of VI. Body green or pink. (p. 172)....--...0-..-2..-0--- saliceti 
Unguis at least 3 times base of VI. Body brown to black. (p. 150)............-...---+-- maculatae 
Unguistsamelengthras Ll oe eee UA ARAVA ooh, Aches: Jee dard ae ee 51 
Unguis shorter: thant [00s eee ee ae, ee 52 
Cornicle shorter than 2 times hind tarsal II; sensoria on III in alata 
fewer thane 10S Cp. 047 yee ee ee ee Jaciniarlae 
Cornicle as long as 2 times hind tarsal II; sensoria in alata 8-10 or more on III................ 85 
