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Show 232 MR. R. SHELFORD ON MIMETIC INSECTS AND [Nov. 4, Harpagid Mantidse, mimic the young larvae of the Reduviid bug, Evlyes amcena, not only in coloration, but also in the peculiar habit of walking about with the abdomen curled over the back (compare figs. 16 & 17). When the young Mantides first emerge from the ootheca they are of a brilliant red colour, the head, basal joint of the antennae, apices of the femora, and the tibiae alone being jet-black. A similar arrangement of colours is exhibited by the young of E. amcena: in these the head, apices of the femora, bases of the tibiae, the wing-rudiments, and some spots on the dorsal surface of the abdomen are black, whilst all the rest is vermilion (compare figs. 18 & 19). The newly-hatched larvae of the bug are very much smaller than the corresponding stage of the Mantis, but after the second moult the size of the former is almost the same as that of their mimics when newly-hatched. The brilliant coloration of the bug is essentially a warning signal, being correlated with an objectionable smell and presumably a still more objectionable taste, judging from the expressions of disgust manifested by two tame monkeys (Macacus cynomolgus) after tasting the specimens I offered them. The young Hymenopus they had eaten with the utmost sangfroid a few days before, from which one may justly conclude that in this case the coloration is deceptively warning or pseudapose-matic (truly mimetic). It is unfortunate that I was unable to rear, or even to keep alive for a few days longer, the young Mantides; but they are notoriously difficult insects to rear, and all my specimens died before I was able to obtain the young of Eulyes amcena. The pupa and adult of this species of Mantis are floral simulators : the former resembles a pink Melastoma; the latter, which is cream-coloured varied with brown, resembles the flower of an orchid of fairly common occurrence ; and I have also seen a young larva which bore a striking resemblance to a small pink flower of an order not known to me. I have had this insect in various stages of its life-history frequently under observation, and can confirm in almost every detail Mr. Annandale's recently published account of the habits of the pupa (cf. P. Z. S. 1900, pp. 839 et seq.). That the insect should mimic in the youngest stage of its life-history a distasteful and conspicuously-coloured bug is a fact of some interest. [The late Mr. L. de ISTiceville states, in a letter to Prof. Poulton, that he had reared some species of Mantidae; one species when newly hatched was remarkably like a small black ant, the deceptive resemblance being so close that a careful scrutiny was necessary to determine the exact nature of the insect. Mr. de Niceville also remarks:- " A Mantis of fair size does not often move but waits for its prey to come to it, but these young ones ran about incessantly looking for their prey, just like the ants they mimicked."] |