358 APHIDS OF THE ROCKY MOUNTAIN REGION 
Genus Mordvilkoja Del Guercio 
Del Guercio, 1909b:11; Baker, 1920a:70; Maxson, 1923:325. 
Characters. Vertex convex; frontal tubercles lacking. Antenna four-seg- 
mented in fundatrix, six-segmented in alata, unguis in fundatrigenia longer than 
base of VI, secondary sensoria, narrow and transverse; permanent sensoria with 
cilia. Cornicle hardly more than a mere ring. Cauda semilunar. Fore wing with 
media simple; hind wing with both media and cubitus. Sexuales apterous and 
without rostrum. 
Living in galls; fundatrix and offspring living together. 
Genotype (monotypical), Brysocrypta vagabunda Walsh. 
Genotype Mordvilkoja vagabunda (Walsh) 
The Poplar Vagabond Aphid 
Byrsocrypta vagabunda Walsh, 1862:306 and 1864 :462. 
Pemphigus vagabunda, Walsh and Riley, 1869:57 and 107; Oestlund, 1887:22; Jack- 
son, 1908a:200. 
Pemphigus oestlundi Cockerell, 1906:34. 
Mordvilkoja vagabunda, Gillette, 1914b:67; Maxson, 1923:325; Oestlund and Heottes, 
1926:75; Gillette and Palmer, 1934:220. 
Fundatrix. Y ellow-green, with head dusky; powdery; appendages pale, dusky distally. 
Body length 4-5; hind tibia .40-.55; antenna .53-.62; rostrum attaining 3d coxa. 
Alate Vivipara. Fundatrigenia. Head and thorax black; abdomen green; pruinose; 
tufted posteriorly; appendages dusky. Body length 2.2-3; hind tibia .85-.90; antenna .85-.88; 
rostrum attaining between Ist and 2d coxae. Media of fore wing simple; hamuli 4-6. Hairs 
in both alata and aptera inconspicuous. Cornicle hardly more than a mere ring often difficult 
to observe. Wax glands on thorax as in Thecabius. Sexupara. Same as fundatrigenia except 
as follows: Unguis only .05-.07 long, sensoria 9-14 on III and rostral IV+V .13-.17. 
Ovipara. Apterous. Body length .80; antenna .23, I .04, II .04, III+IV .03, V .03, VI 
.06+-.03. 
Male. Apterous. Body length .80; antenna .17, I .04, II .03, III+-IV .04, V .05+.01. 
Collections. In large Es phan convoluted, bladderlike leaf galls, com- 
posed of crumpled leaves of a terminal bud on Populus sargenti. Colorado: 
Hugo, Longmont, Brighton, Kuner and Fort Collins. Wyoming: Laramie. Fun- 
datrices May 2 to July 16 (still full of embryos and apparently in their prime), 
alate viviparae (fundatrigeniae) July 10 to 15 (gall still containing numerous 
young), alate sexuparae and sexuales (dead in dry galls from a previous year) 
Aug. 19; rare though common and abundant at times in localities. 
Genus Pemphigus Hartig 
peed 1839:645 and 1841:366; Jackson, 1908a:163; Baker, 1920a:71; Maxson, 1923: 
Characters. Antenna four-segmented in fundatrix, six-segmented in alata; 
seconary sensoria transverse. Wax gland plates developed on aptera; thoracic 
glands normally not evident in alata. Cornicle, a mere ring, developed in alata, 
at least. Cauda semilunar, bearing 2-4 hairs. Hairs inconspicuous. Rostral 
IV+V obtuse; V vestigial and indistinct. Fore wing with media simple; hind 
wing with both media and cubitus. Sexuales apterous, minute and without 
rostrum; ovipara laying single egg. 
Living in true galls on Populus as winter host, many species known to go to 
roots or stems of herbs as summer host. Fundatrix living in same gall as 
progeny. 
Genotype (fixed by Passerini, 1860), Aphis bursaria Linnaeus. 
