Three white butterflies of approximately the same size are found widely distributed over the United States. The most abundant species is the White or Imported Cabbage butterfly. The next in abundance is probably the Checkered White, and the rarest in most localities is the Gray-veined White which is a northern form. =The White or Imported Cabbage Butterfly= _Pieris rapae_ There is probably no butterfly which one can generally find so easily in its early stages as the White or Imported Cabbage butterfly which is found practically wherever cabbages are grown and is generally so abundant that caterpillars and chrysalids are readily discovered. In the Northern states the insect passes through the winter within the chrysalis, coming forth rather early in spring as the familiar white butterfly with black dots upon the wings and blackish front angles of the fore wings. (_See plates, pages 64-65 and 81._) The butterflies that thus appear in spring flit freely about over fields, meadows, and gardens, sipping the nectar of various early flowers through their long, coiled tongues and stopping occasionally to alight upon the leaf of a cabbage or other plant of the mustard family to deposit the small, pale yellow eggs which remain attached by a sort of glue. The adult butterflies continue their leisurely life for a fortnight or more, thus extending the laying of the eggs over a considerable period. About a week after being deposited the egg hatches into a tiny green caterpillar that begins feeding upon the tender surface of the cabbage leaf. It is commonly called the cabbage worm and it is doubtless the most generally destructive insect affecting this crop. It continues to feed for several days before the first moult, after which it becomes decidedly larger and begins to eat again more voraciously than before. It undergoes several successive moults during the next two or three weeks before it becomes full grown as a caterpillar. Unlike most butterfly larvae it has changed very little in its general appearance during its growth. It is always of a pale green color, strikingly like the glaucous green of the cabbage leaf, a fact which doubtless helps to conceal it from the eager eyes of birds and other animals. When the caterpillar is thus full fed it is likely to leave its food plant and find shelter elsewhere. Sometimes it will stop on the lower surface of the outer leaves, but more commonly it will find a piece of board, an overhanging stone, a fence-post, or the side of a building, where it will prepare for the change to the chrysalis. It will do this by spinning a silken thread upon the surface in which to entangle its hind legs and a loop of silk near by with which to hold its body. When these preparations are completed the insect will cast its last caterpillar skin, emerging as a grayish or brownish chrysalis, the color usually varying with the color of the surrounding surface.