RECENT OBSERVATIONS. 
PLANT-LICE—APHIDES. 
Order Hemiptera. Family Aphidid.®. 
■ 
My own attention was especially called to the subject of sorghum 
usects by the following letter from H. A. Weber, Esq., superin- 
endent of the sorghum sugar manufactory at Champaign, in this 
hate, and a patentee of one of the most important processes for 
rystalizing the syrup of that plant: 
“Some of our best fields of sorghum cane are suffering from the 
iepredations of insects. An examination made this morning seemed 
o show that the greatest injury was done by a yellow Aphis. The 
ringed insect has the same color. This louse works chiefly at the 
>ottom of the stalk, on the under side of the leaves. Whether it 
.ffects the roots or not, I could not determine. There is also a 
ead-colored Aphis which works on the top of the plant, but I do 
lot think that it is doing much damage. Occasionally a stalk seems 
o have been killed by this insect; but the yellow louse lias devel¬ 
oped in immense numbers, and I cannot remember of ever having 
een it on sorghum before. I would be very glad to know if this 
asect has been investigated; and if not, could you find the time 
o come over here and examine into the difficulty yourself?’’ 
I received in the same mail with the foregoing a few specimens 
'f the plant-lice mentioned, which proved to represent two species,— 
*ne the ordinary plant-louse of Indian corn, AjAds maiclis, and the 
•ther a form new to me, evidently allied to Cliaitophorus, but appa- 
ently of a species undescribed. These specimens of both species 
vere in various stages of development, including a few winged 
emales and many pupae, together with young of all sizes. 
On the 25th of July I visited Champaign for the purpose of examin- 
ng the infested fields. In one about a mile north of town, belonging 
o the Sugar Manufacturing Company, I found the sorghum seri- 
>usly infested by these two species of plant-lice. 
The corn plant-louse attacked only the upper, fresher leaves of 
he sorghum, nearly all the lice, in fact, being concealed within the 
oil of growing leaves at the tip of the stalk. The second species 
Chaitophorus) had, however, the peculiar habit of working only upon 
he oldest leaves, fully exposed on their under surfaces, clustered 
isually near the mid-rib, but occasionally distributed in patches on 
tearly the whole surface of the leaf; and now and then a small 
! olony would be seen upon the upper surface also. 
