In the first number of this volume one of your contributors, Mr. Clarkson, writing about Citheronia regalis, infers that the moth always appears about the end of May, regardless of the time at which the larva enters the earth, and that it is the habit of the pupa to work out of the earth and lay on the surface of the ground during the winter. The first statement is correct in a certain sense. The insect in question is not uncommon here, and I have had them in numbers. Take a larva captured the first week in August and another the last in September, and allow them to pupate in the same box and to remain together—they will disclose within a day or two of each other; but whether at the last of May or at some other time, depends on the temperature at which they have been kept. Keep the pupa of the one taken in August at a temperature a few degrees lower than that of the September one, and it will disclose much later, perhaps about the time the offspring of the other are entering the earth. I had one pupa that did not disclose till June of the second year. The time of development seems to largely depend on the temperature that surrounds the pupa—a fact that is well known.