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Show 242 MR. E. B. POULTON ON THE PROTECTIVE [Mar. I, T A B L E V.-Experiments with Insects which are protectively Species and Stage. Larva Saturnia carpini ... Larva Mamestra brassicce... Larva Tryphcena orbona... Larva Tryphcena pronuba.. Larva Tceniocampa gothica Larva Phlogophora meticu-losa. Larva Hyponomeuta euony-mellus. Protective resemblance, or habits of concealment, evasion, &c. 1. LEPIDOPTEROUS The green larva with its black bands and pink tubercles harmonizes remarkably well with the heather on which it feeds {Andrew Murray: quoted by Wallace in the essay often referred to). The larva feeds on other plants also, but the special relation of its appearance to that of heather seems to indicate that this is its ancestral food-plant. Very often, however, the larva possesses golden instead of pink tubercles. Commonest variety is olive-brown dorsally and dingy yellow ventrally, with abrupt line of demarcation; a triangular mark containing two white dots on the back of each segment. Other varieties are brown or dingy green or any intermediate tint. Well concealed among the leaves or in tunnels, in cabbage, broccoli, &c, but freely exposed on many plants, although always harmonizing with the surroundings. Colour dingy umber-brown, with darker and paler markings. Feeds on low plants, and in spring on sallow and hawthorn. Larva concealed by day, feeding at night on almost all the plants in gardens. Colour varies from pale yellowish green to dark brown, with brown, black, and pale markings. The whole effect of the larva is green (green ground-colour with one lateral white stripe, and a dorsal and two lateral very narrow pale yellow stripes). Hence harmonizes well with the leaves of the many plants on which it feeds. Disturbed it falls off and has some chance of escaping in the grass or other low-growing plants. The whole effect green or brown (for the larva is dimorphic), as the white dorsal and lateral stripes are inconspicuous. Hence well protected on leaves of food-plant, and the brown varieties on dead leaves and earth. Same protective habit of falling off as noticed in T.gothica. Feeds on many low-growing plants. The larva is coloured with various shades of brown, and is most perfectly protected against brown leaves, which, as I have observed, it almost invariably selects, and upon which it sits motionless by day, feeding at night. If there are no brown leaves it retires by day into a very dark corner among the green leaves. It also has the habit of falling off. Feeds on many trees and low-growing plants. Yellowish grey with black spots, not conspicuous in themselves ; but the larvse live in colonies, spinning a web, the latter certainly attracting attention. Bat the larvaj seem to be safe within it, as in a cocoon. The gregarious nature is doubtless related to the habit of spinning a common web. Feeds on spindle. |