APHIDS INFESTING ECONOMIC PLANTS 405 
B.—Body woolly, conspicuous; body surface dark; antenna six-segmented; 
cornicle mammiform with small base, with diameter same as length of base of 
Wilhairsed psenc onedorsum ofshind tarsal la Cp 18) ssc c.cce see eee ee 
a et Sir, i Sat Oe Re The Woolly Pine Needle Aphid (Schizolachnus pini-radiatae) 
BB.—Body not woolly, difficult to see; body surface pale green, speckled; agile; 
antenna five-segmented; cornicle a mere ring; hairs present on dorsal side of 
hind tarsal I. 
C.—Tibial hairs 2'to 3 times as long as diameter of hind tibia. (p. 14)............ 
fee i re PRN I eet eee The Monterey Pine Aphid (Essigella californica) 
CC.—Hairs on hind tibia about the same length as diameter of tibia. (p. 16) 
SNS eae ll nee Se Rear Be 8 See og CRN a OP p ain ene ee ee a ....... Essigella pint 
AA.—On cones. Body brick-red, shining; cornicle mammiform but small, diameter 
same as length of base of VI; rostrum lancelike, with V not vestigial. (p. 37)............ 
wd ere eee oS re Bae SOS ce ee ep The Pine-cone Aphid (Cinara oregonensis ) 
AAA.—On bark of twigs or small limbs. Body brown, mottled with dusky and 
slightly powdery spots; cornicle mammiform, diameter at base 2 to 3 times length 
of base of VI; rostrum lancelike, segment V not vestigial. 
B.—Hind tibial hairs in aptera spinelike, drooping, .05 long, shorter than diameter 
Ofatibiac (pe 25) cerreenssse The Short-haired Lodgepole Pine Aphid (Cinara brevispinosa) 
BB.—Hind tibial hairs in aptera semi-spinelike, at 45 degrees, .08 long, as long as 
iat CCL MOL CCL came 1) OA) eerreee eae ea cc es a RN 2 oct Se oa oem eee ere es caceet Renee 
NS ker ok Bae PO Ne The Medium-haired Lodgepole Pine Aphid (Cinara medispinosa) 
BBB.—Hind tibial hairs in aptera rather heavy, at 45 degrees to erect, .10 to .15 
long, from once to nearly twice as long as diameter of tibia. (p. 35)-.-.-....-.-.2-...::-.000 
pare ne Seine Seo eas ee The Long-haired Lodgepole Pine Aphid (Cinara murrayanae) 
III. Pinyon, Mexican (Pinus edulis) 
A.—On needles, at bases. Very agile; body apple-green, without dusky spots; antenna 
five-segmented; cornicle a mere ring; rostrum obtuse, with V vestigial. (p. 15)............ 
SS See ee ee eee ees a The Immaculate Green Pine Needle Aphid (Essigella hoerneri) 
AA.—On twigs. Not agile. Body brown, antenna six-segmented; cornicle mammi- 
form, hairy; rostrum lancelike, with V distinct. 
B.—Hairs on dorsum not minute. 
C.—Body light cinnamon-brown or pinkish amber with intersegmental lines 
and lateral areas; length of tibial hairs between once and twice that of 
diameter of tibia; rostral IV .15 to .18. (p. 49)......................-. AS eee ee 
feet fees, Secu Tee AA The Terminal Twig Pinyon Pine Aphid (Cinara terminalis) 
CC.—Body dull black with powdery median line and intersegmental patches; 
length of tibial hairs not longer than diameter of tibia; rostral IV .20 to .22 
long. (p. 28)...... The Black and White Spotted Pinyon Pine Aphid (Cinara edulis) 
BB.—Hairs on dorsum minute; body shining black; not powdery; rostral IV .19. 
@ resmial elim bse (923) foec-ceee tee eee eee The Black Pinyon Pine Aphid (Cinara atra) 
IV. Rocky Mountain Yellow (Pinus ponderosa var. scopulorum) 
A.—On needles. Rostrum obtuse, segment V vestigial. 
B.—Conspicuous; body dark; with pulverulence; antenna six-segmented. 
C.—Conspicuously woolly; dorsal side of tarsal I without hairs; cornicle a 
Shallowscone mbeaning sagre ws Naiesem (pew) &)ceee cert case tanec caren nee ater eee aro eee 
aie Leech ae oa ae eo The Woolly Pine Needle Aphid (Schizolachnus pini-radiatae) 
CC.—Somewhat powdery; dorsal side of hind tarsal I bearing a pair of hairs; 
Corniclesmerelysa Talsed rime. (pew 1) eres ceccc tte acu cents ere renee noes ereeaee res aPene sees am ss 
ee Re tan weskniandeees cee The Powdery Pine Needle Aphid (Eulachnus rileyi) 
BB.—Not conspicuous, difficult to detect, very agile at concealment; cornicle 
mere ring; body pale green, sometimes with dusky speckles and blotches; antenna 
five-segmented. 
C.—Dorsum immaculate; tibial hairs .01, not longer than diameter of tibia. 
(Dont 5.) 2 eet a The Immaculate Green Pine Needle Aphid (Essigella hoerneri) 
CC.—Dorsum with speckles or. blotches; tibial hairs not shorter than diam- 
eter of tibia. 
D.—Tibial hairs .03 to .04, as long as diameter of tibia; dorsum with 
TOWSLOLEOUSKY SDOES Hm (pail ©) nese wees Roe nace aera apenas an eee ann oa tana e eae cence tevarnnsen=sanrs 
ra es ee ee ee he aire Pee The Speckled Pine Needle Aphid (Essigella pini) 
DD.—Tibial hairs longer than diameter of tibia. 
