50 
REMEDIES. 
In respect to treatment it is too early to make any recommenda- 
tions, as effective measures can be taken against this pest only when 
its life history is fully understood. It is clear, as a result of many 
observations, made by us in all parts of the State during the last 
two years, that ground which has been previously in corn, or grass, 
is far more liable to injury by the corn-louse than if it has been pre- 
viously in small grain. There is, therefore, every probability that a 
judicious rotation of crops will be found to impose a sufficient check 
upon the multiplication of this msect, when its life history is knoe 
in full. 
Siphonophora, sp. 
In sorghum fields at Champaign, on the 25th of July, I noticed 
upon the leaves of Panicum a few specimens of a plant-louse which 
I had not previously seen, being associated there with Chaitophorus 
Jlavus, and occurring upon the same plant. It was clearly a Si- 
‘phonophora, but although a considerable number of pupe were 
obtained, I secured only. a single winged specimen, the wings of 
which had been crumpled by accident. I unfortunately neglected to 
make notes of the colors while fresh, and am therefore unable to 
determine definitely the species, but will give here only so much of 
a description of it as is necessary to distinguish it from the other 
plant-lice occurring in these fields. It was again found upon the 
leaves of sorghum, and likewise upon the tops of the same plant, 
on the lith of August but all the specimens obtained aut this 
time were wingless females and pupe. 
Wingless female.—The wingless female is regularly ovate in form, 
the body being 1.3 mm. long by .?7 mm. wide. The antenne do 
not quite reach the tip of the abdomen, and measure 1.1 mm. in 
length. The honey-tubes are black, long, prominent, tapering from 
the base, minutely roughened, and extend beyond the tip of the 
abdomen, measuring 8 mm. in length. The tail is prominent, nearly 
cylindrical in form, broadly rounded at the tip, one-half the length 
of the honey-tubes, and about one-third as long as wide. The fila- 
ment of the antenne is unusually long, measuring more than one- 
third the entire length of the antenne. 
Pupa.—The body of the pupa is about 1.5 mm. long by .75 mm. 
wide, and the antenne are .9 mm. long. The filament of the sixth 
joint is more than twice as long as the third, the basal part of this | 
joint being about half the fifth. The fourth and fifth are nearly 
equal, the latter a little the longer. The honey-tubes are similar to 
those of the wingless female, and measure .17 mm. in leneth. The 
terminal joints of the antenne are black, and the others pale: the 
ea are dark, the tibie pale, except at the tip, and the tarsi 
dusky 
Winged female.—Of this form I can only say that the antenne 
are slightly longer than the body (nearly 1.5 mm. in length), and 
that the filament in the specimen measured was .6 mm. long. The 
wings have the structure of the genus Siphonophora, —three. discal. 
veins, with the third twice forked. 
