THE PEA APHIS WITH RELATIOX TO FORAGE CROPS. 
11 
Mr. D. T. Fullaway (1910) reports having taken J/, trifolii Perg. 
(=pisi) on Soncliu.'^ ohraceus in IlaAvaii, hut an examination of the 
specimens thi'ough the kindness of FuHaway shows them to be 
something other than j^isi. We have also had the privilege of 
examining the specimens collected and recorded by ^Ir. W. M. 
Davidson (1909) as J/, p.si on Urtica lioloscricca, and they prove to 
be of another species. 
We have a numl)er of individual office records reporting J/, 'p'lsi 
on alfalfa. Among these, specimens for which Avere examined by 
the writer, are the followmg: Mr. C. N. Ainshe collected it on this 
host at Prairie Grove, Ark., March 21, 1907, all stages bemg found. 
An examination of this material shows a mixtm*o of J/, f isi and M. 
creelii, although the former species predominates. Mr. Ainshe also 
collected this aphidid at Arhngton, Va., April 6, 1908, on alfaKa. 
Mr. V. L. Wddermuth collected it on alfalfa at Iloltville, Cal., April 
17, 1912, and at Muirkirk, Md., April 28, 1909. At the latter place 
the infested aKalfa had a wilted appearance, and because of their 
abundance this injury was supposed to be caused by the plant-hce. 
Probably the most noteworthy example of pisi occurrmg on alfalfa 
was recorded by ^Ir. J. A. Hyslop, who, on November 12, 1912, 
observed these aphides swarming in an alfalfa field near Fmiksto^ii, 
Md. At this time very few viviparous forms were observed; the 
males and oviparous females predominated, and a few days later 
the black shiny eggs were found abundant on the alfalfa leaves. In 
this same field Mr. Hyslop observed the aphides abundant in May 
(1913), but in August not a single mdividual was fomid. Further 
observations were made in this field by ^Ir. C. M. Packard in October 
(1913), at which time the aphides were agam abundant. ]Mr. J. T. 
^lonell has determmed as this species plant-hce collected on alfalfa 
at Welhngton, Kans., May 4 to July 30, 1909, by Mr. E. O. G. Kelly. 
In all cases where this aphidid occurred on alfalfa it was found on 
the young terminal buds and leaves. 
The foUowuig is a Hst of the authentic hosts of J/, pisi as recorded 
in America. .Vlthough shepherd 's-purse is retamed as a host of this 
})lant-louse, we have never seen specimens of this species collected 
on that plant. Shepherd' s-purse {Bursa hursa-paMoris) , lentil 
(Ervum sp.), sweet pea (Latliyrus odoratus), grass pea (X. sativus), 
alfalfa {Jledlcago sativa) , white sweet clover {Mdlloius alha), 
garden pea and field pea (Pwum sativum), crimson clover {Trifolium 
incarnatiun), red clover {T. pratense), white clover (T. irpens), 
vetches or tares {Vicia ludoviciana, V. gigantea, V. rillosa, et ah). 
The following reliable hosts have been r(^cord(Hl by Ein-opcan 
AVi'iters. Many of the recordinl hosts, such as Gcum, Uhnaria, etc., 
r.re certaiidy incorrect, while othei-s are higldy improbable, and as 
thi^y have not been corroborated since the correct identity of pisi 
has bo(Mi understood, they are not here inchuhMl: Sh<^pherd"s-purse 
