49 
In this same field a third species, less abundant, (Schizoneura 
panicola, Thos.) was found upon the roots. Both the Schizoneura 
and the Chaitophorus likewise occurred upon the common grass- 
like weeds in the field, Setaria and Panicum, the former upon 
the roots, and the latter upon the leaves. The Chaitophorus was. 
found, however, only upon clumps of grass beneath infested rows 
of sorghum, not a single specimen being seen upon the grass in the 
bare spaces of the field, or in those parts where the sorghum 
itself was not infested. It was clear, consequently, that this plant- 
louse passed from the sorghum to the grass, and not from the grass. 
to the sorghum. ‘The Schizoneura, on the other hand, appeared. 
sparingly upon roots of these grasses in a variety of situations, 
both in corn and sorghum fields. 
In corn-fields adjacent, separated only by a fence, not a single: 
specimen of Chaitophorus was seen during a prolonged search, 
although in the border of the sorghum field nearest, this species. 
was extremely abundant and decidedly injurious. 
Several other fields in the vicinity of Champaign were visited at 
this time, and in all of them all three of these plant-lice were 
generally distributed, the two aérial species being frequently massed 
in overwhelming numbers so as thickly to crowd both the lower and 
the upper leaves, with evidently disastrous effect upon the growth of 
the plant. Occasionally the root form of the corn plant-louse was 
seen upon the roots of sorghum, associated with the grass root-louse 
(Schizoneura panicola) already frequently mentioned. In one field 
still a fourth species was found upon the leaves, apparently a Si- 
phonophora, but not to be determined exactly in the absence of 
well-preserved winged specimens. It was certainly different from 
any other plant-louse previously known to infest these or allied 
plants; and is briefly characterized on another page. The corm 
plant-louse and the yellow Chaitophorus were also found upon broom- 
corn in this vicinity, but the root-louse was not detected there. 
Later, in September, an assistant visited some fields of sorghum 
near Heyworth, McLean county, and found there the root-inhabiting- 
species, the Chaitophorus, the undetermined Siphonophora mentioned 
above, and the corn plant-louse (A. maidis), the latter occurring 
only upon the springing tassels. 
Chaitophorus flavus, n. 8. 
{Plate III, Figs. 1—4.1 
DESCRIPTION. 
The genus Chaitophorus, established by Koch in 1854, is especially 
distinguished by the pilose antenne, the filament of the last joint of 
which is longer than its basal part, by the large cauda, and by the 
very short nectaries, wider than long. It is also said by Passerini,, 
Buckton and Thomas to have the antenne 7-jointed, like Aphis; 
eel 
