SUBFAMILY APHINAE BD, 
Lachnus salignus (Gmelin) 
The Giant Willow Aphid 
Dorsa/ 
tuberc/e 
Fig. 53. Lachnus salignus 
Aphis salicis Sulzer, 1776:105 (preoccupied). 
Aphis saligna Gmelin, 1790:2209 (n.n. for Aphis salicis Sulzer). 
Lachnus punctatus Burmeister, 1835:93. 
Aphis viminalis Boyer de Fonscolombe,, 1841:184. 
Lachnus dentatus LeBaron, 1872:138. 
Lachnus viminalis, Cockerell, 1904:262. 
Tuberolachnus viminalis, Knowlton, 1930:159. 
Lachnus salignus, Gillette and Palmer, 1931:878. 
Apterous Summer Vivipara. Blackish, with numerous hairs, causing a grayish appear- 
ance; legs mostly rufous. Body length 4.5-5.5; hind tibia 3-4.5; antenna 1.8-2; rostrum attain- 
ing between 2d and 3d coxae. Hairs on hind tibia sparse, length hardly equal to half diameter 
of tibia. 
Alate Vivipara. Same as aptera, except as follows: Secondary sensoria strongly convex, 
circular to oval, often nearly equal to diameter of antenna, unguis heavy, conical. Hairs on 
hind tibia .05-.07, length almost or quite equal to diameter of tibia. Dorsal tubercle present 
on middle of abdomen. 
Collections. On Salix alba, S. regalis, S. elegantissima and S. sp., on bark; 
in large colonies. Colorado: Fort Collins and Denver. Utah: Throughout 
northern part of state. New Mexico: Pecos. Apterous viviparae July 10 to Nov. 
10, alate viviparae Aug. 9 to Nov. 30; common. 
Genus Longistigma Wilson 
Longistigma Wilson, 1909a:385; Baker, 1920a:17. 
Davisia Del Guercio, 1909a:185. 
Characters. Fore wing with stigma very long and narrow, ending in an 
acute point and extending to tip of radial sector; radial sector almost straight, 
arising some distance proximad of apex of stigma; media fine but not faint, 
twice-branched; hind wing with two cross-veins. Antenna six-segmented; 
unguis elongate, fingerlike. Hairs prominent on appendages. Living on woody 
parts, as trunks and limbs of trees. 
Genotype (monotypical), Aphis caryae Harris. (Not yet recorded from region.) 
. 
Hind. a 
Tibial Spines 
Fig. 54. Longistigma caryae 
