Any one can identify this caterpillar easily, as it is most peculiar. There is a purplish pink cast on the head and mouth of the full-grown caterpillar, and purplish red around the props. The body is a very light blue-green, faintly tinged with white, and yellow in places. On the sides are white obliques, or white, shaded with pink, and at the base of these, a small oval marking. There is a small short horn on the head. But the distinguishing mark is a mass of little white granules, scattered all over the caterpillar. It is so peppered with these, that failure to identify it is impossible.

These caterpillars pupate in the ground. I knew that, but this was before I had learned that the caterpillar worked out a hole in the ground, and the pupa case only touched the earth upon which it lay. So when my Modesta caterpillar ceased crawling, lay quietly, turned dark, shrank one half in length, and finally burst the dead skin, and emerged in a shining dark brown pupa case two inches long, I got in my work. I did well. A spade full of garden soil was thoroughly sifted, baked in the oven to kill parasites and insects, cooled, and put in a box, and the pupa case buried in it. Every time it rained, I opened the box, and moistened the earth. Two months after time for emergence, I dug out the pupa case to find it white with mould. I had no idea what the trouble was, for I had done much work over that case, and the whole winter tended it solicitously. It was one of my earliest attempts, and I never have found another caterpillar, or any eggs, though I often search the poplars for them.