320 APHIDS OF THE ROCKY MOUNTAIN REGION 
cauda (.20-.25 on median line), bearing 3-5 pairs of lateral hairs and length of 
rostral IV-+-V (about same as hind tarsal II). 
Some (Hille Ris Lambers, 1947a:234 and Hottes, 1930:182) have considered 
M. pelargonii Kaltenbach as a synonym of Aphis malvae Mosley but Mosley 
places his species under the heading which says “cornicle shorter than abdo- 
men.” This hardly fits even the subtribe Macrosiphina and certainly not this 
species. 
Macrosiphum pisi (Kaltenbach) 
The Pea Aphid 
Aphis pisum Harris, 1782 :66. 
Aphis onobrychis Boyer de PS 1841 :169. 
Aphis pisi Kaltenbach, 1843:2 
Macrosiphum pisi, Davis, 1s: Bul. 276 (complete account and synonymy) ; Theobald, 
1926:127; Gillette and Palmer, 1934:193. 
Acyrthosiphon pisum (Harris), Hille Ris Lambers, 1947a:247. 
Apterous Summer Vivipara. Pale green; cauda and appendages pale; tarsi and tips of 
tibiae black; cornicle pale becoming blackish distally. Body length 3-3.5; across eyes .55-.64; 
hind tibia 2.3-2.8; rostrum nearly attaining 2d coxa. Hairs slightly capitate; on side of ab- 
domen .01. Cornicle slender, diameter less than that of hind tibia and without reticulation. 
Cauda tapering, bearing 3-5 pairs of lateral hairs and one or two dorsal preapical ones; hairs 
near tip slightly capitate. 
Alate Vivipara. Head and thorax yellow-brown; otherwise as in apterous vivipara. Body 
length 2.3-2.7; across eyes .54; hind tibia 1.7-2; antenna 3.1-3.5; rostrum nearly attaining 2d 
coxa. 
Apt 
VV. 
ia 
85- 1.30) (sen. 2-7) 
G75- 85) Gen 7 Sat tare 
C -. 
(26-30) (70 ~ 95) 
Fig. 382. Macrosiphum pisi 
Collections. On leaves and stems of Loco (Astragalus sp.), Lathyrus odora- 
tus, alfalfa (Medicago sativa), sweet clover (Melilotus sp.), peas (Pisum sati- 
vum), clover (Trifolium sp.). Throughout region. Alate and apterous summer 
viviparae Mar. 22 to Nov. 23; common and injurious. 
Chief Distinguishing Characters. Pale green body, lack of reticulation on 
cornicle, tapering, rather acute cauda with blunt to capitate hairs on terminal 
portion, short rostral IV+V (shorter than hind tarsal II), length of cornicle (not 
longer than antennal III) and length of hind tarsal II (shorter than base of 
antennal VI). 
Hille Ris Lambers (1947a:247) considers the American form as a different 
subspecies namely M. destructor (Johnson) on account of the males in Europe 
being apterous while those in America are reported, according to him to be 
alate. However, Davis (1915:276) mentions occasional apterous males. Theobald 
(1926:127) describes both apterous and alate males. Kaltenbach’s name is here 
retained on account of usage, especially in the economic field. 
Macrosiphum pseudorosae Patch 
Nectarophora pallida Oestlund, 1887 :84 (preoccupied). 
Macrosiphum pseudorosae Patch, 1919:206; Palmer, 1936b:746. 
This species so resembles M. solanifolii that drawings and full description 
seem useless repetition, accordingly it seems best to give only the points which 
differ. These characters are as follows: Heavy black cornicle and appendages, 
longer antenna in apterous vivipara, III 1.05-1.20, IV .76-.87, V .80, VI .20-+-1.20; 
in alate vivipara, III 1.03, IV .95-1.00, V .95, VI .22+1.25) and cornicle never 
longer than III. 
