Page:Darwinism by Alfred Wallace 1889.djvu/270

 feeding-places, those of the two genera Danais and Acræa were never among them.

The two groups of the great genus Papilio (the true swallow-tailed butterflies) which have been already referred to as having the special characteristics of uneatable insects, have also their imitators in other groups; and thus, the belief in their inedibility—derived mainly from their style of warning coloration and their peculiar habits—is confirmed. In South America, several species of the "Æneas" group of these butterflies are mimicked by Pieridæ and by day-flying moths of the genera Castnia and Pericopis. In the East, Papilio hector, P. diphilus, and P. liris, all belonging to the inedible group, are mimicked by the females of other species of Papilio belonging to very distinct groups; while in Northern India and China, many fine day-flying moths (Epicopeia) have acquired the strange forms and peculiar colours of some of the large inedible Papilios of the same regions.

In North America, the large and handsome Danais archippus, with rich reddish-brown wings, is very common; and it is closely imitated by Limenitis misippus, a butterfly allied to our "white admiral," but which has acquired a colour quite distinct from that of the great bulk of its allies. In the same country there is a still more interesting case. The beautiful dark bronzy green butterfly, Papilio philenor, is inedible both in larva and perfect insect, and it is mimicked by the equally dark Limenitis ursula. There is also in the Southern and Western States a dark female form of the yellow Papilio turnus, which in all probability obtains protection from its general resemblance to P. philenor. Mr. W.H. Edwards has found, by extensive experiment, that both the dark and yellow females produce their own kinds, with very few exceptions; and he thinks that the dark form has the advantage in the more open regions and in the prairies, where insectivorous birds abound. But in open country the dark form would be quite as conspicuous as the yellow form, if not more so, so that the resemblance to an inedible species would be there more needed.

The only probable case of mimicry in this country is that of the moth, Diaphora mendica, whose female only is white,