41 
RECENT OBSERVATIONS. 
PLANT-LICK—APHIDES. 
Order Hemiprera. Family ApHipipa. 
My own attention was especially called to the subject of sorghum 
insects by the following letter from H. A. Weber, Esq., superin- 
tendent of the sorghum sugar manufactory at Champaign, in this 
State, and a patentee of one of the most important processes for 
erystalizing the syrup of that plant: 
“Some of our best fields of sorghum cane are suffering from the 
depredations of insects. An examination made this morning seemed 
to show that the greatest injury was done by a yellow Aphis. The 
winged insect has the same color. ‘This louse works chiefly at the 
bottom of the stalk, on the under side of the leaves. Whether it 
affects the roots or not, I could not determine. ‘There is also a 
lead-colored Aphis which works on the top of the plant, but I do 
not think that it is domg much damage. Occasionally a stalk seems 
to have been killed by this insect; but the yellow louse has devel- 
oped in immense numbers, and I ‘cannot remember of ever having 
seen it on sorghum before. I would be very glad to know if this 
insect has been investigated; and if not, could you find the time 
to come over here and examine into the difficulty yourself ?” 
I received in the same mail with the foregoing a few specimens 
of the plant-lice mentioned, which proved to represent two species,— 
one the ordinary plant-louse of Indian corn, Aphis maidis, and the 
other a form new to me, evidently allied to Chaitophorus, but appa- 
rently of a species undescribed. These specimens of both species 
were in various stages of development, including a few winged 
females and many pup, together with young of all sizes. 
On the 25th of July I visited Champaign for the purpose of examin- 
ing the infested fields. In one about a mile north of town, belonging 
to the Sugar Manufacturing Company, I found the sorghum seri- 
ously infested by these two species of plant-lice. 
The corn plant-louse attacked only the upper, fresher leaves of 
the sorghum, nearly all the lice, in fact, being concealed within the 
roll of growing leaves at the tip of the stalk. The second species 
(Chaitophorus) had, however, the peculiar habit of working only upon 
the oldest leaves, fully exposed on their under surfaces, clustered 
usually near the mid-rib, but occasionally distributed in patches on 
nearly the whole surface of the leaf; and now and then a small 
colony would be seen upon the upper surface also. 
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