30 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
From the records that have been made and personal observations 
it would seem that the species of this family are not as abundant in 
Texas as in other states. This may be partly due to the natural fac¬ 
tors, which will be mentioned later, but perhaps largely to the fact 
that sufficient work has not been done on the group. A few new 
species have already been found, and it is to be expected that future 
work will reveal the presence of other new species as well as more of 
the old species. 
The fact that no considerable amount of work has been done on 
aphids should not be taken to indicate that this group of insects is not 
important in this state. As a matter of fact, the economy of this 
state is disturbed as much by the presence of aphids as in any other 
state. Among the destructive species that might be mentioned are the 
“green bug” Toxoptera graminum Rond., the melon or cotton louse, 
Aphis gossypii Glover, the turnip louse, Aphis pseudo-brassicce Davis, 
the oat louse, Aphis padi Linn, and the corn-leaf aphis, Aphis maidis 
Fitch. The periodic losses by the green bug are very severe and are 
well known; the growing of melons and cucumbers have been aban¬ 
doned in some sections on account of the melon louse, and the same is 
true of turnips and related plants subject to the attack of the turnip 
louse. Acres of oats are annually destroyed by the oat louse, although 
it is not appreciated that the loss is caused by this insect. Much 
corn ( Zea mays) and sorghum are badly stunted every year by the 
corn-leaf aphis, although this condition of the plants is popularly 
supposed to be due to the dry weather. 
In the work that has been done to date, several variations in the 
general aphid life-history have been found. Most noted of these is 
the absence of sexes in the seasonal history of the aphids. The gen¬ 
eral statement has been made by Webster (7. c.) that south of the 35th 
parallel the sexual forms of plant lice have been observed but rarely 
except at high altitudes. Sanderson (l. c.) in 1906 reported the occur¬ 
rence of the development of sexual forms of M . granaria in rearing cages 
at College Station. The next occurrence of sexual forms was recorded 
by Yingling in 1916 when eggs and oviparous females were taken in 
the field near College Station. This year, specimens of eggs and ovip¬ 
arous females of Longistigma caryce Harris 1 were taken at Boston in 
northeastern Texas. Although the sexual forms of the oat aphis, the 
cornleaf aphis and the green bug occur throughout the north, they 
have not yet been found in Texas. In the case of the green bug, a 
very careful search was made, but the other species have not yet been 
thoroughly investigated. With the melon louse and the turnip louse 
the sexes have not yet been taken, even in the north. 
1 Determined by Prof. H. F. Wilson. 
