APHIDS INFESTING ECONOMIC PLANTS 401 
AA.—Body light green; sensoria fewer than 34 on III in alata, less than 19 in aptera. 
B.—Sensoria 8 to 10 on III in alate vivipara, 2 to 8 in aptera. (p. 322) ........0.ceccccesee-e 
ee ee, 2 pra Sea ee Cockerell’s Green Goldenglow Aphid (Macrosiphum rudbeckiarum ) 
BB.—Sensoria 16 to 32 on III in alate vivipara, 4 to 8 in aptera. (p. 298)................ 
Pies RD ty Bt PR es ah g Se Hottes’ Green Goldenglow Aphid (Macrosiphum cockerelli) 
Gooseberry—see Currants 
Gourd—see Cucumber 
Grain Crops (Oats, barley, millet, rye, wheat) 
A.—Living on roots. Cauda semilunar; unguis shorter than base of VI; media of fore 
wing not twice-branched. 
B.—Cornicle on small hairy cone; media of fore wing once-branched. 
C= Bodysblachk sp (peg Ll eter eresee aces essere aed eee eee cis wel eon Anoecia graminis 
CC.— Body -vellowstorereenishs (pocl/S)) esse cecowcsesercseecsactenses sete sessouses Anoecia setariae 
BB.—Cornicle absent; media of fore wing simple. 
C.—Hairs on antenna numerous, at least as long as half the diameter of the 
antenna; rostral IV+V .25 long; body olive-green, mottled. (p. 373)................ 
SE Ee CNS aes ery ne ee a i The Grain Root Aphid (Forda formicaria) 
CC.—Hairs on antenna sparse, very short. Rostral IV-+V .17 long; body ~ 
SOLGIGSSTC ENISHI Sy CLLO Wem (Data Lo) meee ke crs cee eee reeas aie nee i ee Forda olivaceae 
AA.—Living generally above ground. Cauda elongate; unguis longer than base of 
VI; media of fore wing twice-branched. 
B.—Body long and narrow; cornicle hardly more than ring. (p. 191)........2....-:::200+ 
Sobcemcet dn tied A tee selene estas olf Pip dg St Male 8 a ae oe Ba ea eae an ee IE ee Brachycolus tritici 
BB.—Body not especially long and narrow; cornicle well developed, tubular. 
C.—Frontal tubercles not exceeding vertex. 
D.—Cornicle cylindrical. 
E.—Media of fore wing once-branched. 
F.—Cornicle shorter than twice length of hind tarsal II. Body 
Pvackerm (pace 2 7: seven oe ces ee Se Ce Toxoptera muhlenbergiae 
FF.—Cornicle as long as twice length of hind tarsal II. Body 
Atay (GON 7A) eae eee The Green Bug (Toxoptera graminum) 
EE.—Media of fore wing twice-branched. 
F.—Body brown; unguis longer than III; sensoria on III in 
alata 15) towel (p.176)e The Rusty Plum Aphid (Aphis setariae) 
FF.—Body black, shining; unguis not longer than III; sensoria 
One Piernealatasd ston 5 1c Dee Lyles rere cee ac ee ae eet Preece 
3a orca perro tip ee meee Pera The Cow Pea Aphid (Aphis medicaginis) 
DD.—Cornicle swollen more or less. 
E.—Cornicle distinctly swollen, three times as long as hind tarsal II. 
(p22) eee ee ee eee The Sumach Aphid (Rhopalosiphum rhois) 
EE.—Cornicle slightly swollen to cylindrical; shorter than 3 times as 
long as hind tarsal IT. 
F.—Unguis shorter than III; cornicle shorter than 1.5 times hind 
tarsal Ils €p.217)2.— The Corn Leaf Aphid (Rhopalosiphum maidis) 
FF.—Unguis longer than III; cornicle longer than 1.5 times hind 
tarsal II. 
G.—Antenna and hind tibia in aptera bearing long, erect 
hairs. 
H.—Body bright green with red on abdominal V, es- 
pecially about cornicle bases. (p. 223)..........-.----ce:s-:c--seo0+ 
The Mediterranean Grain Aphid (Rhopalosiphum splendens) 
HHi= Body: brown on oraye (ps 224.) sect cereee ce ccenas se cese ner eesezee 
Sop OE eee Seeley eRe EES PAG Melle onane oer ae Rhopalosiphum subterraneum 
GG.—Antenna and_hind-tibia of aptera with inconspicuous 
Aroopin ghar rsa (Pye cl Gece reccew ese reece en ener cases a ete m er mee eee = ann aan aceon 
ee eed The Apple Grain Aphid (Rhopalosiphum fitchii) 
CC.—Frontal tubercles well developed, exceeding vertex. 
D.—Frontal tubercles converging; cauda on median line hardly longer 
than hind tarsal II. (p. 340)............ The Green Peach Aphid (Myzus persicae) 
DD.—Frontal tubercules diverging; cauda on median line distinctly 
longer than hind tarsal II. 
