3. The vapourer moth.—About the end of June examine rose trees, fruit trees, willows, oaks, etc., for caterpillars of the vapourer moth. They may be recognised (Fig. 228) by the reddish warts and the tufts of hair which stand out from various parts of the body. Notice that the caterpillars fall into two groups according to size, being, [Pg 365] when full-grown, about 2 in. and 1¼ in. long respectively. Keep the larvae in a breeding-cage until they pupate and change into moths; notice that the moths (the females) which come from the large caterpillars have no wings; while the male moths, which are derived from the small caterpillars, have well-developed wings. A typical butterfly.—The great beauty of butterflies and moths, and the ease with which the stages of their wonderful life-history can be followed, have made these insects favourite objects of study among naturalists of all ages. Among the commonest of butterflies are the well-known cabbage-whites, the caterpillars of which work so much havoc upon crops of cruciferous plants (p. 95). The eggs are laid in May and September upon the leaves, and soon hatch out into small larvae called caterpillars, which feed voraciously and grow rapidly. The larval skin is shed from time to time as it becomes too small. The caterpillar (Fig. 225, A) is somewhat worm-like in appearance, but insect characters may easily be recognised in it. The head is small and shiny. It carries six eye-spots, but the large compound eyes of the adult are not yet visible. A pair of short feelers is present; and the mouth-parts are obviously comparable with those of the cockroach, although the labium (p. 353) has become converted into a spinneret, which gives out the silk threads used for the protection of the pupa. The mandibles, which are used in gnawing leaves, are stout and toothed; the first maxillae are rather small. Behind the head come the three segments of the thorax, each of which bears a pair of short jointed legs; wings have not, as yet, developed. The abdomen really consists of ten segments, although only nine can be seen without dissection. Segments 3 to 6 of the abdomen bear short, unjointed legs called pro-legs or cushion feet, and the last segment bears a pair of appendages called the anal feet. Spiracles are to be seen on the [Pg 366] first eight abdominal segments. In the larva of the green-veined cabbage-white, each spiracle is reddish and surrounded by a yellow border. Fig. 225.—Cabbage White Butterfly. A, larva; B, pupa; C, perfect insect. (All × ⅔.) (B and C from photographs by Mr. A. Flatters)