32 
of Las Cruces. This is the shortest flying Acridiid, I believe, that we have in this 
region. 
The above thirty-five species represent twenty-five genera. 
EXTRACTS FROM CORRESPONDENCE. 
The Corn-Root Plant-Louse. 
I inclose for yonr inspection a stalk of maize. It has now upon its roots quite a 
number of small greenish insects from the size of a pin-head to smaller; also sev- 
eral small common black ants. You will observe the plant is in a languishing con- 
dition, in fact it is not so large as it was a week ago. There is quite a large acreage 
of corn in this county (Montgomery) so affected. My crop, or a portion of it, was 
damaged fully 50 per cent last year by the same insect. — [E. P. Thomas, Md., June 
27, 1893. 
Reply. — The insect which is found upon the roots of your corn is the common 
Corn-root Plant-louse (Aphis maidi-radicis) and the ant is the common and wide- 
spread species known as Lasius aliena. The plant-louse is almost entirely dependent 
for its existence upon the care taken of it by the ants. It seems, in fact, to pass the 
winter only in the nests of this particular ant. It feeds early in the spring upon 
the roots of the smartweed (Polygonum persicaria) and may also live for a short time 
upon the roots of pigeon grass (Setaria). Its main food plant, however, is corn. 
The winged generation appears early in the spring and by this meaus the species is 
dispersed. Were it not for this fact, rotation of crops would be an almost perfect 
remedy. It is, in fact, a remedy of secondary importance, even with the dispersal 
of the species by the winged brood, and continuous cropping of the same fields with 
corn affords the best conditions for the increase of the root-louse. There are no 
actual remedies which are applicable at the present time, but a great deal may be 
done towards lessening the numbers of the insects the coming season. Late fall 
plowing and harrowing by removing the old cornstalks and breaking up the nests 
of the ants after these have become dormant for the winter, a thorough stirring of 
the soil with disk harrows in the early spring to keep down the sprouting herbage, or 
any treatment of the field in the fall which will keep down the smartweed and 
pigeon grass will bring about a beneficial result. — [June 29, 1893. J 
Destructive Locusts in Colorado. 
* * * As near as I can determine the grasshoppers that have been working here 
are the natives. They have hatched out from quite early until within a few days. 
There have been all sizes of them from the most minute to the full grown. So far 
they have done but little toward depositing their eggs. Our experience here may 
do some good to others. First we used a sled 14 to 16 feet long, with boxes like your 
PI. 8, Fig. 1. This was filled with limewater. A great many were killed this 
way. Then they took about the same machine, only made out of iron or tin, and used 
water with coal oil. Then the same thing was used with coal tar and oil. This was 
the most effectual, though more costly. Some farmers caught as high as 200 bushels 
of them. Last, but by no means least, is the bran and Paris green mixture, which 
they like better than any growing crop, and which slays them by the thousands. 
The mixture they are using here is 100 parts of bran, 3 parts of Paris green, and 
some old molasses or other cheap sweet substance to make it stick together. Prob- 
ably two quarts to the 100 parts bran will be enough. This is strewn along between 
the rows of potatoes or corn or through the alfalfa fields. The hoppers will leave 
all other food for it. If there is water they can get to drink near by they die very 
fast; otherwise, it is several hours before they will give up. It is estimated that 
