6 
BULLETIX 276^ JJ. S. DEPAETMEXT OF AGKICrLTUBE. 
IN AMERICA. 
Dr. Cyrus Tlionias was tlie first to observe and record this species 
from America (1878, 1879). The authenticity of this record has been 
doubted by most writers, but we have examined the specimens used 
by Thomas in drawing up his description (Davis, 1913) and find them 
to be the JlacrosipJi um pisi of Kaltenbach. Thomas's specimens were 
collected in Illinois in 1878, which is indicative of its introduction 
into America some years previous, possibly as much as 10 or 15 years 
before. Subsequently and previous to 1899, pisi was reported by 
Oestlund (1886), Smith (1890), and TTdhams (1891). 
Macros I pilium pisi. therefore, was introduced into America fullv 20 
years previous to its appearance in serious niunbers and here we have 
a case analogous to that of the gipsy moth, wliich was present in this 
country for about 25 years before it became a pest (Chittenden, 
1909a). 
Although the losses attributed to this apliidid have been largely to 
garden j^eas, still certain other crops have been much injured by it, 
the actual damage, however, never being apparent as in the case of 
the garden pea. Among other crops field peas are frequently injured 
by pisi. As early as 1900 Dr. Chittenden (1900b) reported uijmy to 
this CTO-p. grown for hay, in Vit'ginia. ^Ir. G. G. Ainslie records the 
total destruction of a plat of Canadian field peas at Xashville, Tenn., 
as early as February 17, iii 1911. 
The fu'st positive record of injuries to clover in America by tins 
plant louse was noted by ^Ir. W. G. Johnson, who wrote in 1900 that 
^' hundreds of acres of red clover have been destroyed by it [21. 
2nsi]. In one instance, reported to me June 13, 1900, ^Ir. C. Silas 
Thomas, of Lauder, Frederick County, Md,, stated that the pest had 
almost entirely ruined 65 acres of red clover. Many other cases 
of a similar nature were reported or observed by us.'' Dr. E. D. 
Sanderson (1900g) reports the occiu*rence of a plant-louse, presumably 
this species, which occmred in injurious numbers on crunson clovei 
as early as 1890. In the same paper Sanderson says: 
One of our best farmers, Mr. Frank Bancroft, of Camden, Del., tells me that lie has 
seen what he judges to be the same louse on crimson clover for at least six or seven 
years [that is, about as early as 1893]. 
In 1900 Prof. F. M. Webster (1900) observed this insect in abun- 
dance on red clover at TTooster, Ohio. Dr. J. W. Folsom (1009) 
rcj^orts injury to red clover in the foUowiag words: 
In 1903 the louse killed an immense amount of red clover and weakened much more 
in Dekalb County [Illinois]. * * * I found on the farm of Mr. A. E. Myei-s, a1 
Millbrook, August 19, 80 acres of dead clover roots in one field. Xot one root in a 
thousand showed any signs of life, and on the ground were thousands of the cast skins 
of the aphid. At cutting the lice had been such a nuisance that the men objected tc 
handling the crop. After cutting the clover never revived. In neighboring fields 
