114 APHIDS OF THE ROCKY MOUNTAIN REGION 
Cornicle cylindrical, transversely wrinkled. Antenna with numerous sensoria, 
at least on III of alate vivipara. Fore wing with media twice-forked. Rostrum 
obtuse, V indistinct, vestigial (fused with IV). Tarsi slender, I triangular in 
lateral aspect. 
Chief Distinguishing Characters. Partial development of frontal tubercles, 
short broad, semilunar cauda and transverse wrinklelike sculpture of the 
cornicle. 
Genotype (monotypical), Aphis pulverulens Gillette. 
Key to Species of Amphicercidus 
1. Hind tibia of both alata and aptera with sensoria (p. 115) ........22....ccccceeeeeecceceeeeeeeeeeeeees maxsoni 
Hind tibia of both alata and aptera without SeEnSOTia.............22..:e--ecccceeeeeeeeeecceceeeeeeeceeeeneeeneeeeen® 2 
2. Sensoria present on IV in alata; cornicle much longer than hind tarsus 
Cp D4) ee Bc ee ee ee ee re flocculosus 
Sensoria absent on IV in alata; cornicle not longer than hind tarsus (p. 115)....pu/verulens 
Amphicercidus flocculosus (Gillette and Palmer) 
Anuraphis flocculosa Gillette and Palmer, 1929a:7. 
Amphicercidus flocculosus, Gillette and Palmer, 1932b:372. 
Apterous Summer Vivipara. Blackish brown on thorax and abdomen; dull orange or clay 
color on head, lateral margins of body and base of cornicle; cornicle and appendages yellowish 
brown to dusky with tarsi and tips of tibiae blackish; entire dorsum covered with powdery 
secretion. Body length 2.75; hind tibia 1.20-1.50; hind tarsal II .20-.22 and slender; antenna 
1.90-2.40; cauda about twice as broad as long; rostrum attaining 3d coxa. 
Alata Vivipara. Head and thorax dark brown to dusky yellow-brown; covered with pow- 
der; appendages and cornicle as in apterous vivipara. Body length 2.30; hind tibia 1.30; hind 
tarsal II .20; antenna 2.2; rostrum rather acute, attaining 2d coxa. Cornicle as broad as 
femora, cylindrical to tapering, marked with very fine and faint transverse wrinkles which are 
often difficult to see, so that cornicles appear smooth; with narrow but distinct flange. 
Lateral tubercles present and distinct but weak on prothorax and all abdominal segments. 
Hairs pointed, .03-.05 long on vertex, body, hind tibia and antenna; on cauda hardly longer 
than on vertex. Ocular tubercle shallow and broad, inconspicuous. Dorsal integument marked 
with delicate reticulations. 
Fig. 124. Amphicercidus flocculosus 
Ovipara. Body length 2.60-3; antenna 1.40-2; hind tibia with sensoria as figured. 
Male. Alate. Same as alate vivipara except as follows: Body length 1.70; cornicle .20 
and as figured. 
Collections. On leaves and twigs of Lonicera sp. and Symphoricarpos sp. 
Colorado: Fort Collins. Utah: Delta. Apterous summer viviparae June 6 to 
July 20, alate viviparae June 10 to Oct. 28, viviparae Oct. 13 to Nov. 24, males 
Oct. 28; not rare. 
Types. U.S.N.M., No. 41456. Paratypes, Colo. Agr. Exp. Sta. Collection. 
Chief Distinguishing Characters. Long cornicle, short cauda, heavy pulver- 
ulence on body and numerous sensoria on antenna of aptera. 
