As noted, the essence of the Papua New Guinea approach is the cultivation of food plants that the butterflies need to complete their life cycles. This is a process that could be replicated elsewhere, and the potential for butterfly farming exists in many countries. In fact, although Papua New Guinea is rich in butterfly species - some 700 of them - it is not unusually so. Other countries also have large numbers of species. There are, for instance 2,500 species known in Costa Rica.
There are some 14,000 species of true butterflies in the world. Although there is possible competition, many countries have no overlap in species at all. As collectors and specialists usually want butterflies from many different parts of the world, the likely competition among countries exporting farmed or wild-caught butterflies is minimal.
Butterflies are supplied to the trade from nearly every part of the world. But because they are most diverse in the tropics, it is likely that the best chance for success in farming them lies there. However, some temperate countries also have an abundance of particular species, and in Europe, the United States, and Japan, butterfly farming is already established on a small scale. This is mainly because many collectors like to rear their own material and they purchase eggs, caterpillars, or chrysalids instead of killed adults. Many dealers in these countries supply a few tropical species that are easy to rear, such as the orchard swallowtail (Papilio aegeus). However, this trade is generally low in volume and value, and temperate-zone butterfly farms are little more than a sideline to normal dealerships.
Some general comments follow on the potential of butterfly farming in various parts of the world.
· Temperate regions of the Old World (Palaearctic Realm). East palaearctic species are in great demand internationally and obtainable with great difficulty. China, in particular, has species of both Parnassius and Papilio that might be farmed. However, all Parnassius species are montane to some degree and none has been farmed yet. Eurasian arctic satyrids, lesser fritillaries, and sulphurs are also in great commercial demand and could perhaps be farmed. Swallowtails are few and are frequently protected.
· Tropical Africa and associated islands (Afrotropical Region). The potential for butterfly farming has not yet been considered in Africa, although the diversity of desirable species is great and the potential market extensive. This area has important swallowtails and Charaxes species (Nymphalidae), but so far as is known, no farming enterprises exist. Experimental or trial farms for butterflies are needed in different parts of Africa.
· Indian subcontinent and Southeast Asian tropics (Oriental Realm). Silk moths, such as Bombyx mori, are commercially farmed in Asia, and butterfly farming would seem to be a natural extension of this. Many Asian butterflies are supplied to dealers, especially from Taiwan and the Philippines, but there is little farming. A very large trade originates in Malaysia, especially for Rajah Brooke's birdwing (Trogonoptera brookiana). Farming is reputed to take place, but most specimens are actually collected. Desirable species of swallowtails, including the black and gold birdwings (Troides species), occur throughout the region. Species belonging to the families Nymphalidae and Pieridae are good candidates for farming, as they are in much demand from dealers.
· Australia, New Guinea, and associated islands to the west (Australasian Realm). Australia is not rich in butterflies, but it has some important endemic species. At least one "farm" exists in Australia, but this appears to be an offshoot of a normal dealership, which rears a few local species to supply at early stages to collectors. Farming is to be encouraged here.
New Guinea's most coveted butterflies, which it shares with Irian Jaya, are the Ornithoptera birdwings. But almost equally desired by collectors and specialists are the Troides birdwings, concentrated to the west of New Guinea.
· Temperate regions of the Americas (Nearctic Realm). There is a considerable trade in New World butterflies from nearly every family (few Lycaenidae and Hesperiidae), but almost all are caught in the wild. There is a strong market for far-northern species (Boloria, Colias, Erebia, Oenesis). Farming these might be possible among Canadian and Alaskan Indian or Eskimo groups.
· Tropical regions of the Americas (Neotropical Realm). This is a likely area for the development of butterfly farming, particularly as its species are completely different from those of the tropics elsewhere. The Morpho and Agrias species of South America are much desired by collectors. It is possible that some of the highly prized morpho butterflies are already farmed (as the law, in fact, requires), but evidence is conflicting, and most biologists believe that the major supply of specimens is from wild populations. Other groups that lend themselves to farming include the swallowtails, nymphalids (including Agrias), and certain members of the family Satyridae. There are large fauna of Riodinidae and Lycaenidae that are potentially suitable for farming.
A dealer in preserved butterflies has recently set up business in the Dominican Republic, and butterfly farms have been established in Costa Rica.
· General. Butterflies in the family Riodinidae and, especially, Lycaenidae seem to be a neglected resource. Many species are relatively small but brightly colored. A major difficulty is that many Lycaenidae have to live with ants for part of their lives and this complicates their rearing.
Some regions with tourist industries are showing interest in establishing "butterfly zoos" or "butterfly jungles." These displays have live butterflies (usually farmed or reared) in artificial habitats resembling the natural ones. Some species, such as the orchard swallowtail (Papilio aegeus), respond well to such conditions. One British dealer has a "tropical jungle" in an enclosed environment in which both temperature and atmospheric pressure are regulated. A large British butterfly zoo has been established and a smaller one has been proposed. The New York Zoological Society is developing a butterfly component in its Wild Asia Hall at the Bronx Zoo, and San Francisco, Portland, Cincinnati, and Tokyo all have thriving insect zoos. Also, the Colombo Zoo in Sri Lanka has a live display and a successful program of butterfly rearing. Similar enterprise could be shown in other places with tourist industries.
Starting a Butterfly Farm
Butterfly farming is initially an ecological and botanical challenge. One must first observe, identify, and propagate the plants that the various species use for food.
Success for butterfly farmers rests on their choosing commercially attractive species. Unfortunately, ecological details of the life histories of suitable species are known in only a few cases. The prospective farmer will be largely on his own and must first develop this information.
Many of the most desirable species are native to primary tropical forests, and they may need protection because of the rate at which their habitat is being destroyed.
Any program to commercially exploit butterflies and other insects must either bypass the rarest, most restricted, and slowest reproducing species; farm them cautiously with a high percentage of adults released; or take them with the greatest of care. Further, there must be adequate habitat protection both in the natural state and in mixed land uses (rather than just agricultural croplands) to support the insects and furnish a continuing supply.
Some competition could occur if live butterflies were exported between countries and used to establish farming enterprises. In general, however, butterflies are easier to farm in their native habitats.