1915] The Aphid Tribe Pterocommini 353 
yellow with tips slightly dusky. Cauda black, entire body 
quite hairy and lightly covered with white powdery wax. 
Antenne with from 20 to 25 round sensoria along the inner 
edge. The prothorax bears a single pair of dentate tubercles 
placed one on each side. Similar tubercles are also found on 
each segment of the abdomen. Wings with normal venation, 
nectaries about twice the length of the tarsi and swollen towards 
the ends. Just back of the flanged tip they are strongly con- 
stricted. Cauda broadly angular. 
Measurements: Length of body 4.1 mm.; width 2.3 mm. 
Length of Antennal segments, III, 0.6 mm.; IV, 0.36.mm.; 
V, 0.85 mm.; sixth and spur, 0.6 mm. Length of nectaries, 
0.59 mm.; Cauda, 0.84 mm. Wing expanse, 9.89 mm. 
A pterous viviparous females: General color reddish brown, 
antenne colored as in the alate form. Head chocolate brown 
and thoracic lobes slightly lighter, but darker than the abdomen. 
Abdomen with a series of dark spots or splotches on the dorsum 
and separated in the middle by a lhght brown median line. 
Similar spots may be found on the sides of the abdominal 
segments. A row of dentate tubercles occurs along side of the 
body, each abdominal segment and the prothorax having one 
on a side. Antenne yellowish brown at the base and shading 
to black at the tip. Legs yellowish brown with the tips of the 
tibia and femora dusky. Tarsi black. Nectaries yellowish 
brown, slightly dusky at the tip. Cauda dusky brown and 
broadly angled. 
Measurements: Length of body 3-7; width across abdomen, 
Pomme, wensta “or seantennal.seements. LLM, 0:61. mm-; 
LVS 028 ormin.; Ve. 0:34 mn Vii 0.9 sm. ; spur,.0:28.. Total 
length, 1.88 mm. Length of nectaries, 0.428 mm. 
Pterocomma populea Kalt. 
Synonomy: 
Aphis populea Kaltenback. 
Cladobius populeus (Kalt) Koch. 
A phioides (Cladiobus) populeus Pass. 
Pterocomma pilosa Buckton. 
Cladobius populeus (Kalt.) Lichtenstein. 
Cladobius populeus (Kalt.) Mordwilke 1-2-3. 
Cladobius populeus (Kalt.) Del geurcio. 
Cladobius populeus (Kalt.) Pergande. 
Cladobius beulahensis Cockerell. 
Cladobius populeus Henrich. 
Cladobtus rufulus Davidson. 
Pterocomma pilosa (Buckton) Wilson. 
Melanoxantherium rufulus (Davidson) Essig. 
