402 APHIDS OF THE ROCKY MOUNTAIN REGION 
E.—Cornicle black, reticulated next to tip; sensoria 7 to 12 on III 
of alata; unguis 4 to 5 times length of hind tarsal ITI. (p. 310)............ 
tile AMOR a MERE, 3 225 The English Grain Aphid (Macrosiphum granarium ) 
EE.—Cornicle pale, without reticulation; sensoria on III of alata 
18 to 28; unguis three times as long as hind tarsal II. (p. 302)............ 
eee eae ean re ae ee The Rose Grass Aphid (Macrosiphum dirhodum) 
Grass, Blue (Poa sp.) 
A.—On roots. Antenna shorter than half body; frontal tubercles lacking; media of 
fore wing simple; body sordid yellow to olive-green. 
B.—Hairs on antenna sparse, .01 long, hardly evident; sensoria 11 to 24 on III of 
alataPACp: (3.73, \ea sere ee he ae cc ete ie ee ee oe ote ec See One ere ee oes ae ee ea Forda olivacea 
BB.—Hairs on antenna not sparse, .04 to .05 long, longer than half diameter of 
III, especially in aptera; sensoria 30 to 55 on III of alate vivipara. (p. 373)........ 
Bro fae, San eee EONS oe SED Naas Pe RLU & fal AL The Grain-root Aphid (Forda formicaria) 
AA.—Above ground. Antenna longer than half body; frontal tubercles present; media 
of fore wing twice-branched; body grass-green or dark brown. 
B.—Cornicle swollen, twice as long as base of VI, without reticulation; sensoria 
46 on III, 19 to 26 on IV in alate vivipara, absent in aptera; cauda short and 
broad, no longer than hind tarsal II, bearing 2 hairs on each side; body brown to 
black, legs dusky. (p. 219):..:......... Gillette’s Blue Grass Aphid (Rhopalosiphum poae) 
BB.—Cornicle cylindrical, 3 to 4 times as long as base of VI, reticulated as far 
as length of hind tarsal II; sensoria 7 to 12 on III, 0 on IV in alata, 1 or 2 on III 
in aptera; cauda elongate, 1.5 to 2 times as long as hind tarsal II, bearing 3 or 4 
hairs on each side; body grass-green; legs pale. (p. 310).........--.22-2---------s-se--ee-eeeeneseoseres 
ete AP ere: Rae ae aro aria 44/S hates oon Aes The English Grain Aphid (Macrosiphum granarium) 
Hawthorne or Haws (Crataegus sp.) 
A.—Body covered with woolly threads; sensoria transverse. 
B.—Living on bark of limbs and stems. Body dark slaty; sensoria annular. 
(pay350) Ai ce ro a a eet ee Eriosoma crataegi 
BB.—Living in curled leaves. Body olive-green; sensoria transverse-oval. (p. 
SOG i aE ee ee Bae reel Su se ne ee an cM a Oe Prociphilus corrugatans © 
AA.—Body naked; sensoria circular. 
B.—Cornicle distinctly swollen (club-shaped) ; body marked with four green spots 
On dorsum. (pce 23a) ee ee ee ee eee Amphorophora crataegi 
BB.—Cornicle not distinctly swollen; body not marked with four green spots on 
dorsum. 
C.—Cornicle twice as long as hind tarsal II. 
D.—Cornicle black throughout; sensoria 6 to 9 on III, 0 on IV of alata. 
Present: on. this: hostvall stummier: (pp) 164) i.c..2.-c0ccleccescee ss esets ears Aphis pom 
DD.—Cornicle pale with black tips; sensoria 12 to 24 on III, 2 to 10 on 
IV of alata, Not present all summers (p) 215) 2 ee 
pains See ee Eee a Pow eS 2D The Apple Grain Aphid (Rhopalosiphum fitchii) 
CC.—Cornicle not longer than 1.5 times hind tarsal II. 
D.—Cornicle marked by transverse imbrications. 
E.—Alata with dark dorsal patch on abdomen; rostral IV+V .10 
long, attaining 2d coxa. (p. 124)............ The Clover Aphid (Aphis bakeri) 
EE.—Alata not with dark dorsal patch on abdomen; rostral IV+V 
«15, long sSurpassin ges 2d COR ads (pnd So) eoce oes eevee pec tse sneer 
see The Long-beaked Clover or Hawthorn Aphid (Aphis crataegifoliae) 
DD.—Cornicle: smooths pid 42 asi le ot acs tec hap nn pep as enadec 
ene eer terete OMe es then Ae The Leaf-curl Plum Aphid (Aphis helichrysi) 
Hollyhock (Althaea rosea). On leaves and stems. 
A.—Frontal tubercles diverging; body red; cornicle at least 5 times as long as hind 
tarsal II, 1.3 to 2 times distance across eyes; cauda 3 times as long as hind tarsal II. 
(pin303)e2c a cxchahecas eS eee ee The Red Hollyhock Aphid (Macrosiphum eoessigi) 
AA.—Frontal tubercles converging; body pale green, alata with dark patch or bands 
on dorsum of abdomen; cornicle 2 to 4 times as long as hind tarsal II, .75 to 1.3 times 
as long as distance across eyes; cauda 1 to 2 times as long as hind tarsal II. (p. 340) 
PIE Re oe: WE, nme PE Ae ne Meet a! The Green Peach Aphid (Myzus persicae) 
