Contributions to an insect fauna of the Amazon Valley : Lepidoptera: Heliconidae / by Henry Walter Bates.

  • Henry Walter Bates
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: Contributions to an insect fauna of the Amazon Valley : Lepidoptera: Heliconidae / by Henry Walter Bates. Source: Wellcome Collection.

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    strict reference to the geographical relations of their varieties. Many closet naturalists, who receive disconnectedly the different varieties in any group, treat them all as inde- pendent species: by such a proceeding, it is no wonder that they have faith in the absolute distinctness and immutability of species. The sexes in the Reliconidce very rarely differ in colours. Secondary sexual characters of another description occur, however, very generally in the Danaoid group. The males, in all the genera hut two (Lycorea and Ituna) of this section, are furnished with a pencil or fringe of long hairs near the costal edge of the hind wings on the upper sur- face. It sometimes arises from the bottom of a shallow horny cup situated between the costal and subcostal nervures; the hairs are long, soft, and adpressed. I was unable to discover any use in this structure; it seemed not to be under the control of the insect. There is no movement in flight, or position in repose, peculiar to the male sex, which might require an instrument to hold the wings together—a function which the position of the hairs, in the place where the fore wing overlaps the hind wing, suggests to the mind. I believe the appendage must be considered as an outgrowth of the male organization, which is not in this case applied to any especial purpose: it may be taken to be of the same nature as the pencil of hairs on the breast of the male Turkey. Growths of one kind or other, on the surface of the wings, peculiar to the male sex, are frequent in Butterflies: in Ranais the males have a small horny excrescence on the disk of the hind wings, which, considering the near relationship proved to exist between the two groups, I take to be homologically the same as the pencil of hairs in the Danaoid Reli- conidce. In the genus Pavonia, belonging to the family Prassolidce, the males in some species have a fringe of hairs near the abdominal border ; in others, a long pencil of the same on the disk; and, again, in others, instead of these appendages, a thickened plate on the inner margin of the hind wings. The most interesting part of the natural history of the Reliconidce is the mimetic analogies of which a great many of the species are the objects. Mimetic analogies, it is scarcely necessary to observe, are resemblances in external appearance, shape, and colours between members of widely distinct families: an idea of what is meant may be formed by supposing a Pigeon to exist with the general figure and plumage of a Hawk. Most modern authors who have written on the group have mentioned the striking instances of this kind of resemblances exhibited with reference to the Reliconidce; but no attempt has been made to describe them fully, nor to explain them. I will give a short account of the leading facts, and then mention some circumstances which seem to throw light on their true nature and origin. A large number of the species are accompanied in the districts they inhabit by other species which counterfeit them in the way described. The imitators belong to the following groups-Papilio, Pieris, Ruterpe, and Leptalis (fam. Papilionidce), Protogonius (Nym- phalidce), Ithomeis (Rrycinidce), Castnia (Castniadce), Dioptis, Pericopis, Rgelosia, and other genera {Bombycidce Moths)*. I conclude that the Reliconidce are the objects imitated, because they all have the same family facies, whilst the analogous species are dissimilar to their nearest allies—perverted, as it were, to produce the resemblance, from * The accompanying Table, in which a number of the most striking of these are arranged in parallel columns, will give some idea of the extent to which this system of imitation prevails.
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