Tuesday, Feb. 11, 2003
* Japanese name: Nanafushi
* Scientific name: Phraortes elongatus
* Description: Stick insects belong to the order of insects called Phasmida, which derives from phasma, the Latin word for phantom. It's easy to identify a stick insect, but it is seeing it in the first place that is difficult, because stick insects so closely resemble sticks. The female is larger than the male. (See photo: The smaller insect is the male, who is copulating with the female).
* Where to find them: On trees and bushes in woodlands and parks from Honshu to Kyushu. Stick insects can be seen from July to November. The stick insect species in the photo can most often be seen on oak trees. Sometimes shaking the branch of a tree is a good way to find them -- just watch for them falling.
* Food: The leaves of oak trees. Stick insects do most of their feeding at night. Like all insects, they grow by molting their exoskeleton. Females molt six times before they are adults; males five times.
* Special features: The superb camouflage of stick insects is their most impressive feature. Some species also look remarkably leaflike. When disturbed, stick insects may play dead for hours. They might also sway gently, like a stick or leaf blowing in the wind. Not all of them are passive, however: Some stick insects spray a chemical at their attacker, and some species can be cannibalistic if kept together. But nanafushi simply straightens its legs, increasing its resemblance to a stick. Reproduction is often done without males. Females lay fertile eggs without mating. The eggs fall to the ground and may not hatch for years. Stick insects have wings, but recent research has shown that they have re-evolved from winged ancestors that then lost their wings. This is an important scientific find; it proves that a complex trait such as wings can evolve once again even if it has been lost.