Jan. 2.

* * * * *

We sent this communication to Professor Forbes, State Entomologist and
received the following reply:

EDITOR PRAIRIE FARMER--There can be hardly a shadow of a doubt that the
injury which your correspondent so graphically describes is due to the
corn root-worm (Diabrotica longicornis), a full account of which will be
found in my report for 1882, published last November.

The clue to his whole difficulty lies in the sentence, "I plant my corn
every year on the same ground." As the beetles from which the root-worms
descend lay their eggs in corn fields in autumn, and as these eggs do
not hatch until after corn planting in the following spring, a simple
change of crops for a single year, inevitably starves the entire
generation to death in the ground.

I inclose a slip, giving a brief account of this most grievous pest; but
the article in my last report already referred to will be found more
satisfactory.

S. A. FORBES.
NORMAL, ILL., January 3.

P.S.--You will probably remember that I published a paper on this insect
in THE PRAIRIE FARMER for December 30, 1882.

* * * * *

The following is the description referred to:

_From the "Crop Report" for 1882._

"The corn-root worm, in the form in which it affects the roots of corn,
is a slender white grub, not thicker than a pin, from one fourth to
three-eighths of an inch in length, with a small brown head, and six
very short legs. It commences its attack in May or June, usually at some
distance from the stalk, towards which it eats its way beneath the
epidermis, killing the root as fast as it proceeds. Late in July or
early in August it transforms in the ground near the base of the hill,
changing into a white pupa, about fifteen-hundredths of an inch long and
two-thirds that width, looking somewhat like an adult beetle, but with
the wings and wing-covers rudimentary, and with the legs closely drawn
up against the body. A few days later it emerges as a perfect insect,
about one-fifth of an inch in length, varying in color from pale
greenish-brown to bright grass-green, and usually without spots or
markings of any kind. The beetle climbs up the stalk, living on fallen
pollen and upon the silk at the tip of the ear until the latter dies,
when a few of the beetles creep down between the husks, and feed upon
the corn itself, while others resort for food to the pollen of such
w