SUBFAMILY APHINAE ; 53 
Genotype, Lachnus roboris Linnaeus (syn. Lachnus fasciatus Burmeister) 
which is the type set by Westwood (1840) or Lachnus punctatus Burmeister 
(1835:93) which is type set by Wilson (1910:151 and 1911b:54).* 
Key to Species of Lachnus 
1. Dorsal tubercle absent; radial sector of fore wing distinctly curved................-.------c-00ce0-c--0e< 2 
Dorsal tubercle present; radial sector of fore wing almost straight (p. 55)-.......0....... saligna 
2. Secondary sensoria present; distinct and tuberculate on III in aptera, large and 
PURO CMa Tem Lima Lat es Cf) 54.) ee a cate oe core ee Ae ee tae oe ee ee rosae 
MS eCONGALY SeNnsOntarabsent Or indistinct onl Lieinvaptera tes esses. oer, ce ee eee 3 
3. Sensoria absent on III of aptera; sternal tubercles absent; tarsal I with a pair of 
AoersatenatrsevAkhocky Mountaimespecres.)'= (ps 53) 22.8. ee. he montanus 
Sensoria often present on III of aptera; sternal tubercles present; tarsal I without 
Porc uairsmn( An EGsHLOpean Species.) 1. (pir do.) so eee ee ree tn eh eek roboris 
Lachnus montanus (Wilson) 
VET eb PE: 
HES 
) Rostrum 1 << 
= ae KI) 
= 108-10 ; 
1 
Fig. 50. Lachnus montanus 
Lachniella montana Wilson, 1919b:42. 
Lachnus montanus, Gillette and Palmer, 1931:876. 
Apterous Summer Vivipara. Rusty or yellowish brown; legs brown to black. Body 3.5- 
3.9 by 2; hind tibia 2.1-3.0; antenna 1.7-1.9, unguis heavy, parallel-sided with conical tip. 
Hairs pointed, spinelike; on hind tibia, sparse, length about half of diameter of tibia; on an- 
tenna and body about the same as on tibiae; a pair present on dorsum of hind tarsal I. Rostrum 
surpassing 3d coxa, very broad and rather obtuse. Sternal tubercles apparently absent. 
Ovipara. Apterous. Color same as in apterous vivipara. Body length 4; across eyes 
.85-.90; antenna 2; hind tibia 3-4. Otherwise as in vivipara. 
Male. Apterous. Color as in ovipara. Body length 2.6; across eyes .75; antenna 1.90; 
hind tibia 2.1; cornicle .25 in diameter at base. 
Collections. On Quercus sp. Colorado: Cimmarron and Glade Park. 
-Apterous summer vivipara Aug. 22 and Oct. 16; rare. 
Cotypes. Granovsky and Colo. Agr. Exp. Sta. Collections. 
This species appears very similar to L. roboris, judging from the few speci- 
mens at hand. The only differences apparent are those given in the key. 
[Genotype Lachnus roboris (Linnaeus) | 
Aphis roboris Linnaeus, 1758:452. 
Lachnus fasciatus Burmeister, 1835:93 and 1006; Schumacher, 1921:184 (synonymy 
declared). 
Pterochlorus roboris, Theobald, 1929:112. 
Lachnus roboris, Hottes, 1930b:185. 
Alate Vivipara. Blackish brown to metallic black; legs tawny brown; wings smoky. 
Body length 3.2-4; across eyes .75; hind tibia 3.6-4; antenna 1.70-2, secondary sensoria rather 
flat, and small, in irregular row along entire length of segments, 6 on III (10-12 in examples 
from Cholodkovsky), 3-4 on IV, 0 on V, unguis conical and heavy. Hairs blunt to pointed, 
spinelike, on hind tibia almost sparse, at angle of 30 to 40 degrees, hardly half as long as 
diameter of tibia; absent on dorsum of hind tarsal I; rostrum attaining abdomen; obtuse, 
*The question as to which species is to be considered genotype is now before the Inter- 
national Commission of Nomenclature. However, both species fall in the same generic 
concept as considered here. 
