September - May * Embryo and Diapause StageA single egg mass is intertwined in a matting of hair from the body of the female. This hair is tan-buff in color, very water repellent, and a good insulator. Masses range in size from 1 to 3 inches long and are sometimes tear dropped in shape. Once the egg mass is produced each egg's embryo immediately starts developing and in a month, the tiny larva is fully formed and ready to hatch. At this point, however, the larva goes into diapause becoming insensitive to cold. An egg mass may contain from 100 to 1,000 eggs. Hatching occurs about the first of May and coincides with the opening of tree buds.