APHIDS INFESTING ECONOMIC PLANTS 407 
DD.—Cornicle not as above, twice as long as hind tarsal II. Sensoria 
absent on IV in alate vivipara. Rostral IV+V .18 to .20, twice as long 
asi base ot antennaleV [i(pil27)i ea The Thistle Aphid (Aphis cardui) 
CC.—Cauda elongate, longer than base of VI; body brown; rostral IV+V 
broad; hind wing with cubital vein vestigial or lacking. (p. 176)...........22..2220.--. 
ais Boh. cag ho ie ae Ie RN be ee ae Oe The Rusty Plum Aphid (Aphis setariae) 
BB.—Cornicle slightly swollen, without flange; body green to pale yellow or 
PUSCVeAnimMaAcCulAatess POW ELYys ml pone 04.) rie eee ee eee ee, A oceans 
wy a aR, Oe pt ten Eh RR ER EE RR See The Mealy Plum Aphid (Hyalopterus arundinis ) 
Potato (Solanum tuberosum). On leaves and stems. 
A.—Dorsum of body immaculate in both alata and aptera; cauda long, twice as long 
as base of VI, bearing 4 to 6 hairs on a side; cornicle reticulated at tip as far as length 
orehind ttarsalsbien(p.324) 2. aos ee The Potato Aphid (Macrosiphum solanifolii) 
AA.—Dorsum of alata not immaculate; cauda shorter than twice length of base of 
VI, bearing not more than 3 hairs on each side. Cornicle without reticulation. 
B.—Alata with black dorsal bands or patch; cornicle without apical striae; unguis 
distinctly shorter than 1. 
C.—Aptera with dorsal blackish horseshoe-shaped marking on abdomen; 
cornicle never swollen; cauda on median line same length as rostral IV++V, 
bearing 2shairs onreach sidew(p2336)' 214.2. eee ee eee Sy Pee Ghee 
Sn es ee ee eee ee oe The Crescent-marked Lily Aphid (Myzus circumflexus) 
CC.—Aptera immaculate; cornicle often swollen; cauda on median line longer 
than rostral IV+V, bearing.3 hairs on each side. (p. 340)......-.....-----:-2-:00eeeeeeeee 
ROBE OP Seer a Se eS Ses Se ape te ee ee ee The Green Peach Aphid (Myzus persicae) 
BB.—Alata with intersegmental dashes and lateral areas dusky, aptera immacu- 
late, with deeper green blotches at each cornicle base; cornicle with 2 to 3 apical 
striae; unguis about 1 long. (p. 342).....-..........---..--- The Foxglove Aphid (Myzus solani) 
Pumpkin—see Cucumber 
Radish—see Turnip 
Raspberry—see Blackberry 
Rhubarb (Rheum officinale). On leaves, in large colonies. 
Body black; frontal tubercles not exceeding vertex; antenna not longer than body; 
cornicle cylindrical, .21 to .29, not longer than III; rostral IV+V obtuse; .13 to .15 
long; sensoria 12 to 18 on III, 0 to 6 on IV of alata; cauda spoon-shaped, bushy. 
Song WC En 28 Sie Poeeintan Rita NS aoe MR Re 2 ac Seer ner eae PRS eS The Bean Aphid (Aphis fabae) 
Rocky Mountain Yellow Pine—see Pine 
Rose (Rosa sp.). On leaves and stems and bark. 
A.—On bark. Dark hairy aphids; cornicle not tubular but mammiform, hairy; an- 
tenna shorter than body; frontal tubercles not developed; hind tarsal I trapezoidal in 
SUG VLE We BUD OM icc terre eee crenata a cantbecnueanenee ean rteees The Hairy Rose Aphid (Lachnus rosae) 
AA.—On leaves and twigs. Pale green aphids (except Mac. nigromaculosum), not 
noticeably hairy; cornicle tubular, not hairy; antenna longer than body; frontal 
tubercles exceeding vertex; hind tarsal I triangular in side view. 
B.—Hairs conspicuously capitate on vertex and dorsum of body and antennal I, 
Pleandsbase of lb especiallyaimaptercde: (ps 250) erect aes yee eee or eeera eee 
DES Bec pi Rs Ute EO a oe ee ee ee The Rose-strawberry Aphid (Capitophorus fragaefol1i1 ) 
BB.—Hairs not conspicuously capitate. 
Ci==Cornicles wol let (ps 239) acceso cee sora rear eercc a at ce ase ee tee ee wee antowan 
ee ee eR ee The Rose and Bearberry Aphid (Amphorophora nervata) 
CC.—Cornicle cylindrical. 
D.—Frontal tubercles diverging; (Fig. 386). Sensoria absent on IV. 
E.—Body red-brown to mahogany-red, alata with black band on 
abdominal V and VI; fore wing dusky at tip; cornicle black, same 
length as IV, reticulated before tip for same length as length of hind 
(ee Gets 9 ak Um Gove Shs 7M eee ec ne ee eR Pe Reet arg Ene era 
ya eae ae The Black and Red Rose Aphid (Macrosiphum nigromaculosum ) 
EE.—Body pale green; wings hyaline. 
F.—Cornicle black; sensoria on III of alata 40 or more, in aptera 
12° to 23 (po esal ee ee The Rose Aphid (Macrosiphum rosae) 
FF.—Cornicle pale to dusky, not black; sensoria not more than 
30 on III of alata, fewer than 12 in aptera. 
