14 APHIDS OF THE ROCKY MOUNTAIN REGION 
not on hairy cone. Cauda rounded to pointed. Tarsal I trapezoidal, bearing 
dorsal hairs; claws bifurcate. Living on needles of pines, especially between 
needles at bases; very quick and active. 
Genotype (monotypical), Lachnus californicus Essig. 
Key to Species of Essigella 
1. Tibial hairs not longer than half of diameter of tibia (p. 15) —-------.----------cs--ce-o--opeeeee hoerneri 
Tibial hairs not shorter than diameter, Of tibia cesstscsccee ees aee career acceseeceea se 2 
2, Tibial hairs about’same length as diameter of tibia.(p. 16)-1-.<=-.4-- 2c ee pini 
Tibial hairs much longer than drameter Of tibia fcc. ccee esse sce bocce verqneceeses oe eeaetes ee 3 
3. Tibial hairs 1,5-2| times as lonevas! diameter of tibia (po 14) 4-0 ee fusca 
Tibial hairs distinctly longer than twice diameter of tibia (p. 14)........-......---------- californica 
Essigella californica (Essig) 
The Monterey Pine Aphid 
Fig. 7. Essigella californica 
Lachnus californicus Essig, 1909a:1. 
Essigella californica, Essig, 1912b:780; Gillette and Palmer 1931:838. 
Apterous Summer Vivipara. Pale green to yellowish, speckled with dusky at bases of 
hairs; with slight pulverulence; appendages pale brownish or slightly dusky, especially dis- 
tally. Body 2 by .6; hind tibia 1.2; antenna .60-.66. Cornicle mere rim without mammiform 
base. Cauda semilunar. Hairs simple, on hind tibia 2-3 times as long as diameter of tibia. 
Alate Vivipara. Body 2-2.2 by .50; hind tibia 1.3-1.9; antenna, .80, III and IV coalesced, 
secondary sensoria large, convex, not tuberculate. First and second pairs of tibiae much 
shorter than hind pair. Hairs pointed, on hind tibia spinelike, 3-4 times as long as diameter 
of tibia; on body short and sparse. Rostrum obtuse, attaining 3d coxa. Fore wing with media 
once-branched. 
Ovipara. Apterous. Body length 1.2-1.3; antenna .45-.50; hind tibia .60-.90, slightly 
swollen on proximal half and bearing large and small sensoria along ventral side. Otherwise 
as in apterous vivipara. 
Collections. On Pinus contorta var. murrayana, rarely P. ponderosa var. 
scopulorum, in tender tips on needles, near bases; solitary. Colorado: Hills 
above Bellvue. Utah: Logan. Fundatrices May 24, apterous summer viviparae 
June 6 to 14 and Oct. 9, alate viviparae June 16 to Oct. 9, oviparae Oct. 2 to 9; 
seemingly rare. 
Type. Essig Collection, No. 47. 
Chief Distinguishing Characters. Long hairs on hind tibia (length of hairs 
3-4 times the diameter of the tibia) and long antenna (in aptera III .20-.25). 
Essigella fusca Gillette and Palmer 
The Brown and Green Pine Needle Aphid 
Esigella fusca Gillette and Palmer, 1924:6 and 1931:839. 
Apterous Summer Vivipara. Head and often pronotum dusky yellowish brown; thorax 
dusky brown; abdomen pale to medium greenish or glaucous green, with dorsum marked with 
dusky spots often coalesced into crossbands or one solid patch fading out on head and 
pronotum; legs mostly dusky to blackish; antenna pale yellowish, dusky distal to middle of 
III. Body length 2-2.2, width .5-.8 parallel-sided; hind tibia .80-1.15: antenna .45-.55, unguis 
