Vietnamese stick insect

Vietnamese stick insect

In a small exhibit at the children's zoo hide the stick insects; and hide very well they do! The stick insects are considered among the best camouflage artists in the animal world. Stick insects comprise their own order within the insect class. Over 2500 species are known worldwide, most of them live in the tropics, although some species are known from temperate areas such as New-Zealand and Europe. In Israel only a handful of species can be found. Stick insects are hemimetabola, i.e. instead of a larva and a pupa there are several nymph stages, which resemble the adult in shape but are sexually immature and are wingless. All stick insects are vegetarian that spend their time moving slowly among the foliage in search of food. Those species that fly do not do it very well. Since running away or appearing frightening will not deter their predators, stick insects rely on camouflage to evade predation. The stick insect body closely resembles a stick, branch or a leaf, their color matches their environment (shades of brown or green), and even their movement mimics the tremble of a branch or a leaf in the wind. At the zoo, peacefully living together, are two stick insect species: the Indian and the Australian spiny stick insect. The Indian stick insect is long and resembles a branch and the Australian spiny stick insect resembles a leaf and is also covered by many small thorns. The two species exhibit interesting and peculiar characteristics during breeding. The Indian stick insect has no need for males. In captivity females lay unfertile, but viable eggs that develop into new females. This phenomenon is known as parthenogenesis. In the wild male Indian stick insects are known, but they are very small and very rare. Unlike in the Indian stick insect, in the Australian spiny stick insect, mating is an essential part of reproduction and the interesting stage is the laying of eggs and hatching of nymphs. After mating the females lay the eggs, which drop to the ground. The shape of the egg resembles seeds and they contain an edible part. These attract ants that carry the eggs to their nests, eat the edible part and move the egg to the nest's garbage dump. There the eggs will be protected during the development. When the nymphs emerge, their body mimics the shape of an ant, which protects them against predation by birds that often avoid eating ants.