78 Annals Entomological Society of America - [Vol. VII, 
oviparous females apparently being absent. As these forms 
are too well-known to entomologists to require a description, 
only a few notes concerning their migration and food plants 
will be given. 
Toxoptera, during the summer time, from about the middle 
of November until March, lve upon various grasses and 
volunteer grain plants. The most important grasses in this 
connection ate Johnson’s Grass (Sorghum halepense), Goose 
Grass (Eleusione indica), Sweet Grass (Panicum laevifolium), 
Teff, Millet, Indian Corn, and Kaffir Corn (Sorghum Sp.). 
The Blue Grass, upon which it is found so frequently in the 
Free State, is not Andropogon hirtus, as reported by C. B. Van 
der Merve and mentioned by F. M. Webster, but is the Sweet 
Grass Panicum laevifolium, which is usually called Blue Grass 
in the Free State and Sweet Grass in the Transvaal. There 
are a number of grasses in South Africa known as Blue Grass, 
without a distinctive common name. From March until June 
or July, Toxoptera is found upon green forage crops such as 
barley, rye, and oats. These give it an opportunity to exist 
from the time that the grass becomes too old for it, or is killed 
by the frost, until the main grain crop of the year is up, about 
June or July. It is also very abundant during the winter time 
upon Rescue Grass (Bromus willdenowii). 
It exists on the winter grain until about September or 
October when it changes to its summer host plants. The 
severe attack usually occurs either in March on the green 
forage crops or in July, August, or September, on the main 
grain crops. The most critical time of the year for Toxoptera 
in South Africa is in October or November, when it becomes 
necessary to change from the grain field to its summer grasses. 
The winters in South Africa are dry and, if rains do not occur 
before October or November, the summer grasses do not come 
up, while, on the other hand, the grain rapidly ripens, becoming 
unfavorable for Toxoptera. At such a time, no doubt, large 
numbers of. Toxoptera are lost in making this change. Some 
of these are always saved by their ability to live upon the roots 
and underground shoots of Johnson’s Grass where they are 
attended by a common, grayish-brown ant, Plagiolepsis dusto- 
diens. ‘This is interesting, inasmuch as H. Maxwell-Lefroy, 
Government Entomologist of British India, reports Toxoptera 
