LIFE HISTORY OF MACROSIPHUM ILLINOISENSIS, 
THE GRAPEVINE APHIS 
By A. C. Baker, 
Entomological Assistant , Deciduous Fruit Insect Investigations t Bureau of Entomology, 
United States Department of Agriculture. 
INTRODUCTION 
A brief note recording the alternation in food plants by this species 
was published by Baker and Turner in 1915 1 . No complete account of 
the different forms, however, is at present in the literature. It seems 
best, therefore, in view of the economic importance of the insect, to 
record briefly the results of some more recent studies and to give an 
account of all the forms of the species. A brief popular account of the 
life history has been given by Quaintance and Baker. 3 
NAME 
The insect under discussion was first described and named by Shimer 8 
as Aphis illinoisensis. Later Thomas 4 described it as Siphonophora 
viticola. For many years Shimer’s name was lost sight of, owing, no 
doubt, to the obscurity of its publication, and practically all of the 
references to the insect as a pest are found under the name “ viticola 
Thos.” Davis, 5 in listing the aphids of Illinois, called attention to 
Shimer’s description and placed ‘‘viticola Thos.” as a synonym of 
“illinoisensis Shimer.” 
OCCURRENCE 
The species occurs quite abundantly on wild grapes (Vilis spp.) in the 
more southern parts of the country and often is quite destructive to 
cultivated varieties (PI. 8, C, D). Specimens have been received from 
the District of Columbia, Georgia, Indiana, Maryland, Missouri, Mississippi, 
North Carolina, New Jersey, New York, Oklahoma, Pennsylvania, Texas, 
and Virginia. What may also be the same species was taken on grape 
by F. Noack, at Campinas, Brazil, during September, 1898. 
1 Baker, A. C., and Turner, W. F. the brown grape aphid. In Science, n. s. v. 41, no. 1066, 
p. 834. 1915. 
2 Quaintance, A. and Baker, A. C. aphids injurious to orchard fruits, currant, goose¬ 
berry, and grape. U. S. Dept. Agr. Fanners' Bui. 804, 42 p., 30 figs. 1917. 
3 Shimer, Henry, a new grape aphis. In Prairie Farmer, v. 34 (n. s. v. 18), no. 20, p. 316. 1866. 
4 Thomas, Cyrus, siphonophora viticola thos. , the grape-inhabiting aphis. In his Eighth report 
of the State Entomologist on the noxious and beneficial insects of the State of Illinois, p. 55. 1879. 
6 Davis, J. J. a list of the aphididae of Illinois, with notes on some of the species. In Jour 
Econ. Ent., v. 3, no. 6, p. 486. 1910. 
Journal of Agricultural Research, 
Washington, D. C. 
jz 
(83) 
Vol. XI, No. 3. 
Oct. 1511917 
Key No. K—57 
