RSSNew Guinea, the world's second largest island, lies at the heart of the Australasian center of species diversity. Papua New Guinea, with its unlimited range of hues and shades, has a butterfly fauna amounting to some 820+ magnificent species, including the world's largest butterfly, the Queen Alexandra's Birdwing (Ornithoptera alexandrae). The lovely Birdwing butterflies are especially well-known among naturalists, entomologists and collectors.
The reason for this diversity of butterflies and insects in general is the tropical climate and the mountainous topography. The many mountain valleys and islands not only offer a variety of different habitats but also lead to the evolution of many new species which are peculiar to Papua New Guinea and are sometimes only found in a restricted area. For instance many of the Delias species are only found on certain mountain peaks, while the Queen Alexandra's Birdwing is confined to the lowland rainforest of the Popondetta region in Oro Province. New Guinea's insect fauna include the Hercules Moth (Coscinocera Hercules) which is the largest moth in the world, or one of the largest stick insects in the world, Eurycnema Goliath.
The caterpillars of butterflies feed on many specific foodplants, some of them poisonous to large animals like the milkweeds or the alkaloid-rich Aristolochia vines which represent the food plants of the Birdwing caterpillars. Storage of these poisons provides these caterpillars with protection against predators and sometimes even makes the adult butterflies distasteful to birds. Many of these butterflies have bright aposematic colouration to warn potential predators of their bitter taste.
Palatable species sometimes copy these colourations to trick predators and gain some protection for themselves (like the blue day-flying moth Alcides agathyrus which is thought to copy the swallowtail Papilio laglaizei) whereas other species, like the leaf-like coloured Doleschallia, prefer a cryptic appearance to escape their enemies.
Although different species of butterflies have developed various strategies to escape their many predators and parasites or to adapt to changing conditions of their environment, their survival is easily threatened by destruction of their natural habitats, in particular the rainforests, through human activities. The existence of Queen Alexandra's birdwing has been endangered by logging operations and agricultural clearing of the rainforests.
