8 
BULLETIN 276^ U. S. DEPARTMENT OF AGEICULTUEE. 
sweetish taste because of the honeydew covering it, is rather rehshed 
by cattle. Mr. Lawson 'Caesar (1911) reports that feeding cattle 
with infested vines was supposed by one farmer to be the cause of 
the death of some of his cattle, but there seems to be no proof and the 
conclusions were probably incorrect. 
DISTRIBUTION AND ORIGIN. 
As will be seen on the accompanying map (fig.. 1), this aphidid is 
generally distributed over the United States and southern Canada, 
especially in the eastern haK, where it is more or less destructive 
every year. It is Hkewise generally distributed throughout Europe. 
Theobald (12) reports this species from Natal, South Africa, and Dr. 
B. Das (in litt.) has found it plentiful in British India. 
Fig. 1. — ^tap showing the known distribution of the pea aphis ( Macrosiphum pisi) in America. (Original.) 
As an injurious species it occurred first in America along the At- 
lantic coast. The following year (1900) it was very destructive in 
Wisconsin and Michigan, and has since worked its way westward 
to the Pacific coast. Recently Mr. F. C. Bishopp has sent in speci- 
mens from Texas, where it seems to have gained a strong foothold.^ 
The fact that M. pisi was first observed in this country within 
comparatively recent years and was first apparent in destructive 
1 Mr. Bishopp has kindly given the writer permission to quote his letter accompanying the specimens, 
under date of Aug. 4, 1914, which reads as follows: 
The pea aphis was observed to be doing damage to English peas (garden poa-^) in experimental plats just 
east of Dallas, shortly alitT lh(» middle of May (i;il4). The peas began bloomiuLr about April On 
May 2') the growth of ttm jx' i> wu-; i)ractically stopped and many vines turned yellow on accoiuit of the 
exceedingly heavy infe^tati )n of anhidos. Ou May 31 ])ractirally all of the pea vines v-(>re dead without 
having produced a single p )d. During the first three wee^s of June, ladv beetles, ])rincip;illy Hippodamia 
convcrQcns, were observed to be destroying the aphides in great numt)ers. and a few of ttio pea vines were 
almost cleared of the "lice" and started to grow a little; however, they never made any fruit. 
Mr. Bishopp further stated that the sweet peas and garden peas throughout the city of Dallas were prac- 
tically destroyed. 
