142 NINETEENTH REPORT STATE ENTOMOLOGIST OF MINNESOTA—IQ22 
(100) CATAMERGUS FULVAE (Oéestlund) 
Found on Jmpatiens fulva; larvel forms pulverulent. 
(101) CATAMERGUS PURPURASCENS (Oestlund) 
Found on Thalictrum purpurascens; pale green. 
(102) CATAMERGUS CYNOSBATI (Oestlund) 
Found on Ribes cynosbati. 
98. Group Typical Cylindricornia. Large and typical forms with 
cornicles long and cylindrical and with an area of closed reticulations 
on the apical part; sensoria present in the spurea as well as in the 
migrant and usually restricted to the third segment. The following 
genera are found in Minnesota: 
a. Third segment of the antennae with numerous, scattered sensoria _(poly- 
sensoria) ; found on Compositae.......... Genus TRITOGENAPHIS 99 
b. Sensoria not so numerous and scattered; found on Rosaceae and other 
PLATES HC ices peo nr eaE ie Oe eee eee Genus MACROSIPHUM too 
c. Sensoria few and arranged in a single row; in the spurea the sensoria are 
usually: «1-4 Wor “wantines “oso sea eee Genus ACYRTHOSIPHON tor 
99. Genus TRITOGENAPHIS gen. nov. Type: Aphis rudbeckiae 
Fitch, 1851. Very large and typical Macrosiphini found on Composi- 
tae, and usually brown, red, vermillion, or green in color. A large 
number of our Macrosiphini belong to this genus: 
(103) TRITOGENAPHIS RUDBECKIAE (Fitch) 
Found on Rudbeckia, Silphium, and golden glow; bright vermilion 
red in color. 
(104) TRITOGENAPHIS AMBROSIAE (Thomes) 
Found on Iva and Ambrosia; color seal-brown or red brown 
(105) TRITOGENAPHIS CHRYSANTHEMI (Oestlund) 
Found on Bidens; color dark red brown. 
(106) TRITOGENAPHIS ERIGERONENSIS (Thomas) 
Found on Erigeron canadensis; color green. 
(107) TRITOGENAPHIS LUDOVICIANAE (Oestlund) 
Found on Artemisia ludoviciana; color green with white pulveru- 
lent matter. 
100. Genus MACROSIPHUM (Passerini) Schouteden, Igor. 
Type: Aphis rosae Linnaeus, 1758. The sensoria on the antennae are 
not so numerous as in the foregoing genus, and are less scattered, show- 
ing a tendency to be arranged in a row and may be present on segments 
3-5. It may be noticed that Passerini never once associated his Macro- 
siphum with a species altho he published several papers and species 
since he proposed the new term; Schouteden was the first to associate 
the term as a genus with a species in 1901, and this association should 
be ascribed to him and not to Passerini, who only suggested the term 
and never made use of it. 
