This is not unusual in the forests of New Guinea region, home of the Queen Alexandra's birdwing (Ornithoptera alexandrae), the largest butterfly in the world, and to hundreds of thousand of other invertebrates. But most of New Guinea’s bug life remains a mystery.

A world undiscovered

While our knowledge of the Queen Alexandra birdwing is fairly good, this is not the case for hundreds of thousands of mostly smaller bugs and creepers of all kinds. In fact, New Guinea’s microcosm of terrestrial and freshwater invertebrates has been very poorly sampled and studied.

But there are exceptions, such as insects and molluscs. Around 90 species of crabs, crayfish and other crustaceans have been discovered, and we know that more than 30 of these are found nowhere else - they are endemic to New Guinea.

High levels of endemism are often observed with insects, in New Guinea like elsewhere. Non-endemic species are primarily derived from the east, but Australian species are also found, especially in the island’s southern savannas.

How many are there?

There may be 300,000 species of insects in New Guinea, although this figure may vary by as many as 100,000 species. When it comes to specific taxonomic groups, estimates are relatively easier. For example, we know that despite its relatively small area, Papua New Guinea ranks 12th in the world in terms of endemism of large butterflies.¹