APHIDS INFESTING ECONOMIC PLANTS 397 
GG.—Sensoria on VI 7 to 11. (p. 362).............. Pemphigus nortonii 
DDDD.—Gall formed by pouchlike swelling of leaf base (Figs. 431 and 
440). 
E.—Gall located on upperside of leaf; exit a slit on underside along 
midrib (Fig. 440). Sensoria present on VI. (p. 365) -......20....eccecceeeeceeeeeeee 
Sra catia a arene Ae sesh The Poplar-vein Gall Aphid (Pemphigus populi-venae) 
EE.—Gall located on underside of leaf; exit a slit on upperside of 
leaf along midrib (Fig. 431). Sensoria absent on VI, rarely 1 on V. 
(p. 359)....The Poplar Sugar-Beet Root Aphid (Pemphigus balsamiferae) 
Cowparsnip—see Celery 
Cucumber and Muskmelon (Cucumis sp.) and Squash, Gourd and 
Pumpkin (Cucurbita sp.) 
A.—Frontal tubercles not exceeding vertex; antenna shorter than body. 
B.—Body black; sensoria 12 to 18 on III, 0 to 6 on IV, of alata; cauda bushy, 
with 6 or 7 hairs on each side. (p. 135)..............::--0ceeeee-0-- The Bean Aphid (Aphis fabae) 
BB.—Body pale yellow to dark green, usually yellow-green; sensoria in alata 7 
to 10 on III, 0 to 2 on IV; cauda not bushy, with only 2 or 3 hairs on a side. 
CD am LS 9, a seeee ee cteeres ete eR es oe, Sh The Cotton or Melon Aphid (Aphis gossypii) 
AA.—Frontal tubercles exceeding vertex; antenna as long or longer than body. 
B.—Body pale green, dark dorsal patch or bands present on abdomen of 
alata; frontal tubercles converging; cornicle cylindrical or slightly swollen, 
not reticulated, .30 to .60 long; cauda .20 to .25 long, with 3 hairs on each 
SIGE CD G40 eee ern es as The Green Peach Aphid (Myzus persicae) 
BB.—Body pale green or pinkish, without dorsal patch in alata; frontal 
tubercles diverging; cornicle cylindrical, reticulated on distal end, .85 to 
1.15; cauda .40 to .50 long, with 4 to 6 hairs on each side. (p. 324).............-..... 
eee aes es Sera i eS The Potato Aphid (Macrosiphum solanifolii) 
Currants and Gooseberries (Ribes sp.) 
A.—Causing puffed red blisters on leaves of cultivated currant. Hairs capitate, es- 
pecially conspicuous in aptera; alata with dark dorsal patch on abdomen; sensoria 
present on III, IV and V in alata. (p. 268)............ The Currant Aphid (Capitophorus ribis) 
AA.—Not causing red blisters on leaves. Hairs not conspicuously capitate. 
B.—Curling leaves very tightly. Frontal tubercles hardly exceeding vertex. 
C.—On gooseberry. Cornicle shorter than 4 times as long as hind tarsal II; 
rostral IV-+V .12 long, 1.5 times hind tarsal II. (p. 280) -.........0....:ccccccesceeeleseceeeeceeeeees 
epee st Pre Sti POE ot The Gooseberry Witch-broom Aphid (Kakimia houghtonensis) 
CC.—On wild red or squaw currant (Ribes cereum,). Cornicle 4 to 5 times as long 
as hind tarsal II; rostral IV+V .17 to .19, twice as long as hind tarsal II. 
as long as hind tarsal II; rostal IV+V .16 to .17, 1.5 times as long as hind tarsal 
SPT OWE (my a 2S 2) eer ces esee sete ot cask eee Pac cas Sos iets cece asen tenes bios cuteseta. nuduatescceiccdeestt Kakimia ribe-utahensis 
BB.—Curling leaves moderately or not at all. 
C.—Frontal tubercles well developed, exceeding vertex. Cornicle more or less 
swollen towards tip; hairs slightly capitate but inconspicuous. 
Dis Tibiaer danke (pi 4.239) ocsescascacesecte anasto ces eezae tte eeeseceess Amphorophora nigricornis 
DD.—Tibiae pale. 
E.—Alata with dark dorsal patch on abdomen and with sensoria present 
OneLV and. Vi sahairs-miniutem (ps 242) soc ccantee cnn =eneetseeee-anseee Amphorophora sonchi 
EE.—Alata without dark dorsal patch on abdomen and with sensoria 
absent on IV and V;; hairs quite noticeable. (p. 240)........-..-2...---::sccseeceeeeseeeeee 
Se ee eae Oeemeree ae The Ornamental Currant Aphid (Amphorophora ribiella) 
CC.—Frontal tubercles not well developed, not exceeding vertex; cornicle cylin- 
drical or tapering towards tip; hairs slightly capitate or simple. 
D.—Antenna not shorter than body; hairs slightly capitate; unguis at least 
4 times as long as base. : 
E.—Sensoria usually present on IV and V in alata; sexuales present in 
thestall.. (py 278) cccce eee tag ece aoe asereonene The Dogberry Aphid (Kakimia cynosbati) 
EE.—Sensoria never present on IV and V in alata; sexuales present in 
WAL ga G8, 728 eee ope ee emcee ple Benne Eee PCT eie re crn te eee Kakimia ribe-utahensis 
DD.—Antenna shorter than body; hairs simple; unguis shorter than 4 times 
base. 
