BBC top 10 new species of decade includes stick-insect

A spectacular stick-insect, a rare specimen of which is looked after at the Natural History Museum, is in a top 10 new species of the decade list.

The species list was put together by scientists at the BBC and Conservation International and they feature in the BBC2 TV programme Decade of Discovery, shown tonight.

The stick-insect’s common name is Chan's megastick and, at about the length of your arm, it is the longest insect in the world.

Chan's megastick is found in Borneo and was only given its scientific name, Phobaeticus chani, in 2008.

Scientists think it probably lives high up in the rainforest canopy, something that would have helped it stay hidden from view for so long.

There are only 6 specimens of Chan's megastick known worldwide.

The largest is looked after at the Museum in the research collection behind the scenes. It is the female from which the species was named, known as the holotype. Its overall length is 56.7cm and it was donated by Datuk Chan Chew Lun.

The males and females are quite different in appearance.

The female is much larger, wingless, dark green with whitish blotches, and has large spines on its middle and hind legs. The males are small with wings, mostly brown in colour, and they lack large spines on the legs.

As in closely related species, females of Chan's megastick probably lay one egg at a time.

The egg shape is probably unique in the insect world as it has curved wing-like structures. These may help them disperse as they fall from the forest canopy.

Chan's megastick’s reign as the world’s longest insect could soon come to an end, however.

In north Queensland, Australia, there is a recently named stick-insect species Ctenomorpha gargantua, which might be even longer.

The female is known from photographs of 2 living individuals, and one of these has been calculated to measure an astonishing 61.5cm.