AGRICULTURAL DISCUSSIONS AT THE STATE 
FAIR, ROCHESTER, 1862. 
On Tuesday evening, September 30, Dr. Asa Fitch, Entomologist of the 
Society, delivered an interesting lecture on the Aphis, which has been so 
destructive to the crops of oats, spring wheat, barley and rye. The farmers 
present had many questions to be answered, and the discussions which 
arose after Dr. Fitch had concluded his remarks, were very interesting. 
Hon. A. B. Conger, ex-president, who was chairman of the meeting, 
pursuant to a resolution of the meeting, prepared and published a summary 
of the conclusions arrived at, on the subjects discussed. 
THE APHIS. 
1. It is a general law of nature, that insects injurious to vegetation 
have their parasites and other natural enemies, which are sooner or later 
developed in sufficient numbers to exterminate the race they feed upon. 
2. The aphis avense, the insect which, during this season and the last, 
has destroyed large crops of oats, spring wheat, barley and rye, is 
undeniably of the louse species, having almost incredible powers of 
fecundity, developing from a single female, and without the intervention of 
the other sex, over two millions in twenty days. 
3. Its enemy is of the lady bug species, perfectly harmless itself to 
vegetation, but an active poison, probably, to the domestic animals, should 
they be turned upon the stubble too soon after harvest, when the lady bug 
or coccionella has finished its attack upon the aphis. 
4. The aphis is unlike the midge or Hessian fly, in the above particulars, 
except in the general characteristic of their being severally provided with 
the parasitic destroyers, and in having their ravages limited by conditions 
of the atmosphere and of heat and moisture, which are not clearly defined 
in some cases by early maturity, and by constitutional peculiarities in cer¬ 
tain varieties of seed which possess a greater toughness of the pericarp, or 
outer covering of the seed. 
5. The practical question which remains for the farmer is to determine 
whether he may not, by careful selections of seed, and by a more thorough 
tillage and judicious application of plant-food, develop his crop, so as by 
increasing its constitutional vigor and in effecting an early maturity, to 
render it a less easy prey to the ravages of any of the insect tribe now 
known, or that may hereafter be discovered. 
Benefits of Underdraining. 
On Wednesday evening, October 1st, the benefits of underdraining 
elicited a very animated discussion, the substance of which we give in 
addition to the very valuable summary by Mr. Conger, which embodies the 
