52 SEVENTEENTH Report STaTE ENTOMOLOGIST OF MINNESOTA—1918 
twigs and leaves of trees and woody plants; characteristic of the 
Chaitophorina and Callipterina. Third, those feeding on annual plants 
as characteristic of most of the Aphidina. In form of the partheno- 
genetic generations two distinct types may be distinguished in the 
subfamily. First, where all the parthenogenetic generations acquire 
wings before reproducing, as in the Callipterina. Second, where these 
same generations are either winged or wingless which is the condition 
of the other groups of the subfamily. 
KEY TO THE GROUPS OF TRIBES OF THE APHIDINAPD 
1. Cornicles short and rim-like situated on cone-shaped hairy tubercles; anten- 
nae usually less than one-half the length of the body and provided with long hairs; 
spur short. Iound on the bark of woody plants. . . . I. LACHNINA 
—Cornicles not situated on hairy tubercles, cylindrical and conspicuous, some- 
times much reduced or variously modified, rarely hairy (Trichosiphini). Usually 
found on annual plants or the growing parts and leaves of woody plants. 
2. 
2. Cornicles short and of the truncate type; if longer than broad then variously 
enlarged, rarely cylindrical. .. . 3. 
—Cornicles long and cylindrical; sometimes short but then not of the truncate 
UVP. Wh Xs 4. 
3. Antennae and legs with long slender hairs; cauda broad or pointed, rarely 
enlarged at apex; the parthenogenetic summer generations in part wingless (Spuriae) 
and in part winged (Migrants); colonies usually strongly gregarious; found on the 
leaves of woody plants, sometimes on bark. . . . Il. CHAITOPHORINA 
—Antennae and legs smooth or with short hairs; cauda usually globate at apex 
and anal plate more or less emarginate; the parthenogenetic summer generations all 
acquire wings (Migrants) before reproducing; colonies sporadic, i. e. more or less 
seattered; found on leaves of woody plants, rarely on annuals. 
» lil, CALLIPTERINA 
4. The cylindrical cornicles provided with numerous long, spreading hairs; Asiati¢e 
HORM S sary wel we IV. TRICHOSIPHINA 
—Cornicles not hairy, or at most with a few hairs; found mostly on annual 
plants, sometimes on leaves of woody plants. . . . V. APHIDINA 
I. Group LACHNINA 
Retzius, 1788, DeGeer’s Genera. Sub Abdomen tuberculatum. 
Latreille, 1807, Gen. Crust. Vol. 38. Sub Abdomen bituberculatum. 
Burmeister, 18385, Handb. Entom. Vol. 2. Sub Lachnus (genus). 
Koch, 1854, Die Pflanzenl. Heft 1. Sub Lachniden (tribe). 
Passerini, 1863, Aphid. Ital. Sub Lachninae (subfamily). 
Buckton, 1876, Monogr. Vol. 1. Sub Aphidinae (subfamily). 
Thomas, 1879, Report 8. Sub Lachnini (tribe). 
Mordwilko, 1908, Acad. Imper. Vol. 18. Sub Lachnina (group). 
The group Lachnina has been long in coming to its present limits 
and position in the family. The group was foreshadowed by Retzius 
(1783) and Latreille (1807). Burmeister (1835) erected the genus 
Lachnus, the foundation of the present group. Koch (1854) united 
a second genus with Lachnus under the tribal name Lachniden which is 
a nomen nudum. Passerini (1863) first gave the group the subfamily 
name Lachninae. Buckton placed it as a tribe under the Aphidinae. 
