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Lepidoptera.—The butterflies of the South Temperate Subregion are not numerous, only about 29 genera and 80 species being recorded. Most of these are from Chili, which is sufficiently accounted for by the general absence of wood on the east side of the Andes from Buenos Ayres to South Patagonia. The families represented are as follows: Satyridæ, with 11 genera and 27 species, are the most abundant; Nymphalidæ, 2 genera and 8 species; Lemoniidæ, 1 genus, 1 species ; Lycænidæ, 3 genera, 8 species ; Pieridæ, 6 genera, 14 species; Papilionidæ, 2 genera, 8 species; Hesperidæ, 4 genera, 13 species. One genus of Satyridæ (Elina) and 2 of Pieridæ (Eroessa and Phulia) are peculiar to Chili. The following are the genera whose derivation must be traced to the north temperate zone: Tetraphlybia, Neosatyrus, and 3 allied genera of 1 species each, were formerly included under Erebia, a northern and arctic form, yet having a few species in South Africa ; Argyrophorus, allied to Æneis, a northern genus; Hipparchia, a northern genus yet having a species in Brazil ;-all Satyridæ. The Nymphalidæ are represented by the typical north temperate genus Argynnis, with 7 species in Chili; Colias, among the Pieridæ, is usually considered to be a northern genus, but it possesses representatives in South Africa, the Sandwich Islands, Malabar, New Grenada, and Peru, as well as Chili, and must rather be classed as cosmopolitan. These form a sufficiently remarkable group of northern forms, but they are accompanied by others of a wholly Neotropical origin. Such are Stibomorpha with 6 species, ranging through South America to Guatemala, and Eteona, common to Chili and Brazil (Satyridæ); Apodemia (Lemoniidæ confined to Tropical America and Chili. Hesperocharis and Callidryas (Pieridæ), both tropical ; and Thracides (Hesperidæ) confined to Tropical America and Chili. Other genera are widely scattered; as, Epinephile found also in Mexico and Australia ; Cupido, widely spread in the tropics ; Euryades, found only in La Plata and Paraguay, allied to South American forms of Papilio, to the Australian Eurycus, and the northern Parnassius ; and Heteropterus, scattered in Chili, North America, and Tropical Africa. We find then, among butterflies, a large north-temperate element, intermingled in nearly equal proportions with forms derived froni Tropical America; and the varying degrees of resemblances of the Chilian to the northern species, seems to indicate successive immigrations at remote intervals.
Coleoptera. It is among the beetles of South Temperate America that we find some of the most curious examples of remote affinities, and traces of ancient migrations. The Carabidæ are very well represented, and having been more extensively collected than most other families, offer us perhaps the most complete materials. Including the Cicindelidæ, about 50 genera are known from the South Temperate Sub-region, the greater part from Chili, but a good number also from Patagonia and the Straits of Magellan. Of these more than 30 are peculiar, and most of them are so isolated that it is impossible to determine with precision their nearest allies.
The only remarkable form of Cicindelidæ is Agrius, a genus allied to the Amblycheila and Omus of N.W. America. Two genera of Carabidæ, Cascellius and Baripus, are closely allied to Promecoderus, an Australian genus; and another, Lecanomerus, · has one species in Chili and the other in Australia. Five or six of the peculiar genera are undoubtedly allied to characteristic Palæarctic forms; and such northern genera as Carabus, Pristonychus, Anchomenus, Pterostichus, Percus, Bradycellus, Trechus, and Bembidium, all absent from Tropical America, give great support to the view that there is a close relation between the insects of the northern regions and South Temperate America. A decided tropical element is, however, present. Tropopterus is near Colpodes, a Tropical and South American genus; Mimodromius and Plagiotelium are near Calleida, a South American genus; while Pachyteles, Pericom psus, Variopalpus, and Calleida are widely spread American groups. The preponderance of northern fornis seems, however, to be undoubted.
Six Carabidæ are known from Juan Fernandez, 3 being identical with Chilian species and 3 peculiar. As the island is 350 miles from the mainland, we have here a proof of how readily insects may be transported great distances.
The Palæarctic affinity of the South Temperate Carabidæ may be readily understood, if we bear in mind the great antiquity of the group, and the known long persistence of generic and specific forms of Coleoptera; the facility with which they may be transported to great distances by gales and hurricanes, either on land
or over the sea; and, therefore, the probability that suitable · stations would be rapidly occupied by species already adapted
to them, to the exclusion of those of the adjacent tracts which had been specialised under different conditions. If, for example, we carry ourselves back to the time when the Andes had only risen to half their present altitude, and Patagonia had not emerged from the ocean (an epoch not very reniote geologically), we should find nearly all the Carabidæ of South America, adapted to a warm, and probably forest-covered country. If, then, a further considerable elevation of the laud took place, a large temperate and cold area would be formed, without any suitable insect inhabitants. During the necessarily slow process of elevation, many of the tropical Carabidæ would spread upwards, and some would become adapted to the new conditions ; while the majority would probably only maintain themselves by continued fresh immigrations. But, as the mountains rose, another set of organisms would make their way along the highest ridges. The abundance and variety of the North Temperate Carabidæ, and their complete adaptation to a life on barren plains and rock-strewn mountains, would enable them rapidly to extend into any newly-raised land suitable to them; and thus the whole range of the Rocky Mountains and Andes would obtain a population of northern forms, which would overflow into Patagonia, and there, finding no competitors, would develope into a variety of modified groups. This migration was no doubt effected mainly, during successive glacial epochs, when the mountain-range of the Isthmus of Panama, if moderately increased in height, might become adapted for the passage of northern forms, while storms would often carry insects from peak to peak over intervening forest lowlands or narrow straits of sea. If this is the true explanation, we ought to find no such preponderant northern element in groups which are proportionally less developed in cold and temperate climates. Our further examination will show how far this is the case.
Lucanidæ.—Only four genera are known in the sub-region. Two are peculiar, Chiasognathus and Streptocerus, the former allied to Tropical American, the latter to Australian genera ; the other two genera are exclusively South American.
Cetoniidæ.—These seem very scarce, only a few species of the Neotropical genus Gymnetis reaching Patagonia.
Buprestidæ.—These are rather numerous, many very beautiful species being found in Chili. Nineteen genera are represented in South Temperate America, and 5 of these are peculiar to it; 3 others are South American genera ; 2 are Australian, and the remainder are wide-spread, but all are found also in Tropical America. The only north-temperate genus is Dicerca, and even this occurs also in the Antilles, Brazil, and Peru. Of the peculiar genera, the largest, Dactylozodes (26 sp.), has one species in South Brazil, and is closely allied to Hyperantha, a genus of Tropical America; Epistomcntis is allied to Nascis, an Australian genus; Tyndaris is close to Acmãodera, a genus of wide range and preferring desert or dry countries. The other two are single species of cosmopolitan affinities. On the whole, therefore, the Buprestidæ are unmistakeably Neotropical in character.
Longicorns.—Almost the whole of the South Temperate Longicorns inhabit Chili, which is very rich in this beautiful tribe. About 75 genera and 160 species are known, and nearly half of the genera are peculiar. Many of the species are large and handsome, rivalling in beauty those of the most favoured tropical lands. Of the 8 genera of Prionidæ 6 are peculiar, but all are allied to Tropical American forms except Microplophorus, which belongs to a group of genera spread over Australia, Europe, and Mexico. The Cerambycidæ are much more abundant, and their affinities more interesting. Two (Syllitus and Pscudocephalus) are common to Australia and Chili. Twenty-three are Neotropical; and among these Ibidion, Compsocerus, Callideriphus, Trachyderes, and Xylocharis, are best represented. Twenty are altogether peculiar, but most of them are more or less closely allied to genera inhabiting Tropical America. Some, as the handsome Cheloderus and Oxypeltus, have no close allies in any part of the world. Holopterus, though very peculiar, shows most resemblance to a New Zealand insect. Sibylla, Adalbus, and Phantagoderus, have Australian affinities ; while Calydon alone shows an affinity for north-temperate forms. One species of the northern genus, Leptura, is said to have been found at Buenos Ayres.
The Lamiidæ are less abundant. Nine of the genera are Neotropical. Two (Apomecyna and Ecocentrus) are spread over all tropical regions. Ten genera are peculiar; and most of these are related to Neotropical groups or are of doubtful affinities. Only one, Aconopterus, is decidedly allied to a northern genus, · Pogonochorus. It thus appears, that none of the Lamiidæ exhibit Australian affinities, although these are a prominent feature in the relations of the Cerambycidæ.
It is evident, from the foregoing outline, that the insects of South Temperate America, more than any other class of animals, exhibit a connection with the north temperate regions, yet this connection is only seen in certain groups. In Diurnal Lepidoptera and in Carabidæ, the northern element is fully equal to the tropical, or even preponderates over it. We have already suggested an explanation of this fact in the case of the Carabidæ, and with the butterflies it is not more difficult. The great mass of Neotropical butterflies are forest species, and have been developed for countless ages in a forest-clad tropical country. The north temperate butterflies, on the other hand, are very largely open-country species, frequenting pastures, mountains, and open plains, and often wandering over an extensive area. These would find, on the higher slopes of mountains, a vegetation and conditions suited to them, and would occupy such stations in less time than would be required to adapt and modify the foresthaunting groups of the American lowlands. In those groups of insects, however, in which the conditions of life are nearly the same as regards both temperate and tropical species, the superior