44 
NEW CORN INSECT —Diabrotica longicornis. Say. 
During the past season the corn in certain sections of Northwestern 
Illinois was found to be withering and dying, without any apparent 
cause. Even in fields which were clean and well cultivated, and 
the soil rich and fertile, this was observed to an extent indicating 
a loss of at least one-third of the crop. For some time this was a 
mystery which the farmers were unable to explain. At length Dr. 
Boardman, of Stark county, who resided in the section where this 
occurred, made an examination in order to find out, if possible, the 
cause of this phenomenon. The following, from a letter written by 
him to Prof. French, will show the result. He says: 
“I address you at this time in regard to the larvae of some un¬ 
known insect which I find working on the corn. Since my return 
from the State Field-meeting (of Natural History Association), 
numerous complaints have been made to me in regard to a worm 
that was preying upon the roots of corn, and to-day, having the 
first leisure moment that I have had, I visted the infested fields. 
The field examined was a fine, rich, level prairie, thoroughly under¬ 
drained with tile, and has been cultivated in corn for a number of 
years. The ground was clean and the crop had been well attended. 
The corn was a fair growth, and had just begun to ear. At first, 
one would not think there was anything amiss with it, hut on closer 
inspection I could see that many hills were withering, and on taking 
hold of them, they pulled up very easily, and the fibrous roots were 
found eaten away. A closer examination revealed hundreds of small 
white worms about half an inch long and the size of a No. 5 Klager- 
pin. The corn had thrown out its first row of brace-roots, and in 
these I found numerous worms at work. Some hills that had been 
attacked earlier had not developed brace-roots, but had thrown out 
another set of fibrous roots from the stalk, and these had been 
attacked by the worms. I thought the worms were the larvae of 
some Scarabaeidae, but could not determine. The field examined 
contained eighty acres, and had a large pasture adjoining it on the 
west. The damage in this field will, I think, amount to at least 
one-third of the entire crop. I examined several hills that appeared 
as yet unaffected, but found the worms in the brace-roots.” 
Further examination proved that the culprit was the larva of a 
little plant-beetle, very closely allied to the well known Striped 
Cucumber-beetle (Diabrotica vittata ), which will be found described 
and figured on page 165 of my first report. 
