122 NINETEENTH REPORT STATE ENTOMOLOGIST OF MINNESOTA—IQ22 
a. Corhicles*cylindrical, pale-) habitat Ropulsesn(Sai) eee a ct eee 
Genus PTEROCOMMA 22 
b. Cornicles more or less distinctly swollen; in color pale yellow or red; 
habitat sS alata (Populus) eciasccs centre Genus MELANOXANTHERIUM 23 
c. Cornicles slightly swollen and abruptly constricted at distal end with a 
very small opening; body covered with flocculent matter as in the Pem- 
phiginae:,habitabes Glenna eens ee eee Genus PLOCAMAPHIS 24 
22. Genus PTEROCOMMA Buckton, 1879. Type: Pterocomma 
pilosa Buckton, 1879. Cornicles cylindrical. No representative of 
this genus is known from Minnesota but is likely to be found. 
23. Genus MELANOXANTHERIUM (Koch) Schouteden, root. 
Type: Aphis salicis Linnaeus, 1758. Size large; cornicles pale, yellow 
or red and distinctly swollen. The following species are known from 
Minnesota : 
(12) MELANOXANTHERIUM SALICIS (Linnaeus) Schouteden, 
IQOI 
Color bluish black with white patches of pulverulent matter on 
the abdomen; spur of the terminal segment of the antennae 
shorter than the cornicles; veins of the wings with dusky bor- 
ders, anal vein especially conspicuous in this respect. Rather com- 
mon on branches of willow. 
(13) MELANOXANTHERIUM BICOLOR (Oestlund) 
Color reddish brown, the pulverulent spots less conspicuous; spur 
of the terminal antennal segment about equal to the cornicles and 
twice as long as the basal part; veins clear without dusky bor- 
ders. Much rarer species, sometimes found in small colonies with 
the above form. 
(14) MELANOXANTHERIUM SMITHIAE (Monell) 
Color dark brown; terminal segment of the antennae longer than 
the cornicles; cornicles short, not more than twice as long as 
broad. 
24. Genus PLOCQAMAPHIS gen. nov. Type: Melanoxanthus 
flocculosus Weed, 1891. Color dull yellowish brown; body very floc- 
culent; cornicles longer than broad, swollen above the middle and 
strongly contracted to a very small opening without a flange. The 
very distinct type of cornicles with the conspicuous flocculent matter 
would indicate distinct generic differences. One species is recorded: 
(15) PLOCAMAPHIS FLOCCULOSUS (Weed) 
This peculiar form is not rare on willow 
25. Tribe CHAITOPHORINI. The Chaitophorini are medium 
to small in size in comparison with the preceding tribe, the body is 
more or less depressed, with shorter legs and rostrum; antennae about 
