53 
.any facts which have come under my observation go to show 
; a similar service is rendered to the lice of our corn and sor- 
m fields by this same everywhere abundant ant. 
Summary. 
y way of recapitulation of the facts relating to the plant-lice 
sting sorghum and broom-corn, we may say briefly that four of 
se species are now known to injure these crops, three of them 
cting the foliage and tops, and the fourth confining its injuries 
die roots. It is also probable that at least one of those hitherto 
ad only upon the leaves, likewise seriously injures the plant by 
ining the sap from the roots early in the season. All four of 
se species continue their depredations until October, retarding the 
wth of the plant by appropriating the sap and deadening the leaves, 
L in broom-corn further injuring the crop by staining the brush, 
i first of these species, which may be called the yellow sorghum 
ut-louse, described here under the name of Chaitophorus flavus, may 
distinguished from the others by its nearly uniform lemon color in 
stages, and by the fact that it attacks only the lower leaves of 
plant, upon the inferior surface of which it clusters, usually 
Test the midrib, having the effect, when numerous, to deaden 
leaves entirely for a variable distance above the ground. On a 
re minute examination, it may be recognized by the fact that the 
ennae are but five-jointed, while in the other aerial species they 
six-jointed, that the lioney-tubes are low, conical tubercles, and 
t the back of all the forms is ornamented with several longitudinal 
is of small tubercles, bearing stiff bristles. 
Tie second species is the well known plant-louse of Indian corn, 
his maidis, and occurs chiefly upon the upper leaves of the plant 
;il the head appears, when it attacks this also. The color of 
3 species is dark green in all except the winged forms, and in 
se the head and thorax are black. The antennae are short, not 
re than two-tliirds the length of the body; the honey-tubes are 
>minent, cylindrical, slightly enlarged* in the middle and expanded 
the tip. The slender terminal portion of the antennae, called in 
s paper the filament, is only about equal in length to the third 
at of the same. 
Che third aerial species is s’imilar in general appearance and in 
aation to the corn Aphis just described, but may be distinguished, 
on careful examination, by the fact that the filament of the 
tennae is one-third its whole length, being nearly twice as long 
the third joint, while the cornicles are cylindrical and taper 
qflarly from the base to the tip. The root-louse is white or 
lowish-white, and easily recognized by the fact that it is entirely 
ffitute of honey-tubes, these being replaced by circular pores 
ich open upon the surface. The antennae will likewise serve for 
recognition, as they are without the slender, filament-like termi- 
1 portion with which all the other species are furnished. From 
3 root form of the corn plant-louse, which sometimes occurs in 
mection with it, this species may be distinguished by the two 
aracters last mentioned—the absence of the honey-tabes and of 
; 3 antennal filament. 
