ORDER:
Phasmatodea
Description and Distribution
Variously known as walking sticks, stick insects, ghost insects and leaf insects, they comprise over 3,000 species. Their name is based on the Greek word phasma, meaning a phantom or apparition. They can be found in tropical and temperate zones around the world. The longest members of this group reach a length of 13". Like all insects they have a segmented body including: head, thorax, and abdomen. They have six segmented legs which are widely separated along the thorax. The feet of these insects possess both claws and suction pads, making them excellent climbers. Some species of stick insect have 2 pairs of wings (the males do anyway). Females of some species may possess vestigial wings. They also feature characteristic antennae and exoskeletons. The males are capable of flight which provides for genetic variety while the ladies are homebodies, being flightless. Some species practice chemical warfare by secreting a substance similar to pepper spray, an irritant to the eyes and mouth of any creature contemplating having the insect for a meal. The females are usually larger than the male. The stick insects are nocturnal, using the day to remain immobile and camouflaged by their appearance. At night they become active, moving about to feed. Stick insects are entirely herbivorous, feeding on bramble, ivy, cherry, and other leaves. Many appear as twigs of different colorations, but some appear as a leaf, contrary to popular lore.
Reproduction
Members of this insect family are primarily parthenogenetic though sexual reproduction between males and females does occur in some species. The females can lay unfertilized eggs which hatch into only females who also lay unfertilized eggs. Unsurprisingly, populations of these insects are overwhelmingly female. The eggs are laid singly and also are camouflaged, appearing as tiny dark seeds. Eggs may simply be dropped, buried or glued under a handy leaf.
Growing up buggy
Stick insects practice incomplete metamorphosis. The nymphs look like small adults sans wings or reproductive organs. They molt to grow larger, usually about 6 times as they grow into adulthood. To molt they suspend themselves from a stick or twig and let gravity help they emerge from their old exoskeleton. They then may use the shed skeleton for a snack. Their life span is about 18 months.
Hey, how about a leg up here!
Stick insects share the ability with some other insects in being able to regenerate a limb if one is lost. This ability exists only for immature members who haven't attained their final molt. The limb regenerated may be smaller than the lost limb. Antennae are not replaceable.
It isn't easy being a bug
Walking stick insects are preyed upon by birds,reptiles, rodents, spiders, and other insects.
Stick insects as pets
They make good pets inasmuch as they are low maintenance, requiring little more than food and a place to enjoy it. They can be happily kept in a small terrarium. They can feed on lettuce or privy leaves. Water requirements can be met by using a mist sprayer on the food and the cage interior. Eggs and nymphs must be managed when changing cage materials. Simply casting out cage materials can introduce non-native insects into an environment where they can become an agricultural pest. Eggs/nymphs can be managed by freezing, crushing, or burning.
Sources:
http://www.biology.ualberta.ca/old_site/locke.hp//walk_sticks.htm
http://www.ivyhall.district96.k12.il.us/4TH/KKHP/1INSECTS/walkingstick.html
http://www.thaibugs.com/Articles/stick%20insect%20facts.html
http://en.wikipedia.org/wiki/Stick_insect