XXXII 
INTRODUCTION. 
idea being, in all these desired experiments, to reduce the bulk and expense of the 
diluents by forcing the poisons in finer and fewer particles up among the plants 
rather than down upon them, through small perforations, or (what will prove pref- 
erable) crescent-shaped slits of various dimensions in nozzles that will bear great 
pressure from within. 
4. Test how far, i. e., over how much ground, on the above principles, a pound of 
pyrethruin may be made to go and still prove effectual. 
5. Ascertain, if possible, whether the moths are not killed by sucking at the glands 
where the plant is poisoned from below. 
6. Ascertain the effects of these different poisons on the eggs. 
7. Always note the difference in effect on the very young and the full-grown 
worms. 
8. Observe well in the woods and in the neighborhood of infested fields if the 
Aletia larva can be found feeding on any other plant, searching particularly plants 
of the same family (Malcacea) or that to which cotton belongs. 
9. Note and study any mites found preying on the eggs. 
10. Send me a summary of the experiments made with yeast ferment or beer mash 
by the middle of August. 
11. Study well the influence of ants in the cotton field. and in how far they prove 
destructive to Aletia, especially to the egg or young larva. 
Respectfully, 
C. V. RILEY, 
Chief U. S. E. C. 
Another circular (No. 10) referred to other insects affecting either the 
root, stem, branch, leaf, involucre, blossom or boll, but, for reasons stated 
in the Preface, need not be repeated here. 
In the meantime the work we had left unfinished in the Department, 
together with some additional work done by Mr. William Trelease under 
direction of our successor, had been prepared for publication, and was 
issued in August, 1880, by Professor Comstock as author, under the 
title: Eeport | upon | Cotton Insects | prepared | under direction of the 
Commissioner of Agriculture in pursuance of an Act of Congress ap- 
proved June 19, 1878 | By | J. Henry Comstock | Entomologist to the 
Department of Agriculture | Washington | Government Printing Office 
| 1879 | . This is referred to in the following pages either as the " De- 
partment Eeport on Cotton Insects " or as " Comstock's Cotton Insect 
Eeport." 
On July 1, 1881, the U. S. Entomological Commission was transferred 
by previous act of Congress from the Department of the Interior to the 
Department of Agriculture, and we were soon thereafter asked to re- 
sume the position, which we had resigned two years previously, of ento- 
mologist to this last Department, under whose auspices the investiga- 
tion has since been carried on. The work in 1881 and 1882 was chiefly 
devoted to the preparation of the present report and to the testing and 
perfecting of the machinery that had been devised, the Cotton Conven 
tion held in the autumn of 1881 at Atlanta, Ga., offering a favorable 
opportunity, and much time having been given to the preparation of 
an exhibit of such machinery, which the Commissioner desired should 
be made there. Such further experiments as were made with insecti- 
