The Naturalist in Nicaragua by Belt, Thomas, 1832-1878

I walked some distance into the forest along swampy paths cut by charcoal burners, and saw many beautiful and curious insects. Amongst the numerous butterflies, large blue Morphos and narrow, weak-winged Heliconidae, striped and spotted with yellow, red, and black, were the most conspicuous and most characteristic of tropical America. Amongst the beetles I found a curious longicorn (Desmiphora fasciculata), covered with long brown and black hairs, and closely resembling some of the short, thick, hairy caterpillars that are common on the bushes. Other closely allied species hide under fallen branches and logs, but this one clung exposed amongst the leaves, its antennae concealed against its body, and its resemblance to a caterpillar so great, that I was at first deceived by it. It is well known that insectivorous birds will not touch a hairy caterpillar, and this is only one of numberless instances where insects, that have some special protection against their enemies, are closely imitated by others belonging to different genera, and even different orders. Thus, wasps and stinging ants have hosts of imitators amongst moths, beetles, and bugs, and I shall have many curious facts to relate concerning these mimetic resemblances. To those not acquainted with Mr. Bates's admirable remarks on mimetic forms, I must explain that we have to speak of one species imitating another, as if it were a conscious act, only on account of the poverty of our language. No such idea is entertained, and it would have been well if some new term had been adopted to express what is meant. These deceptive resemblances are supposed, by the advocates of the origin of species by natural selection, to have been brought about by varieties of one species somewhat resembling another having special means of protection, and preserved from their enemies in consequence of that unconscious imitation. The resemblance, which was perhaps at first only remote, is supposed to have been increased in the course of ages by the varieties being protected that more and more closely approached the species imitated, in form, colour, and movements. These resemblances are not only between insects of different genera and orders, but between insects and flowers, leaves, twigs, and bark of trees, and between insects and inanimate nature. They serve often for concealment, as when leaves are imitated by leaf-insects and many butterflies, or for a disguise that enables predatory species to get within reach of their prey, as in those spiders that resemble the petals of flowers amongst which they hide.

(PLATE 1. ALLIGATORS IN SAN JUAN RIVER.)