Classification and Range
There are approximately 2,000 tropical species of walkingsticks, with 10 species living in North America. The Vietnamese walkingstick is a member of the Phasmidae family, and is in the order Phasmatodea. Vietnamese walkingsticks range throughout Vietnam and Southeast Asia.
Australian walkingsticks are found in northern Australia and New Guinea.
Vietnamese walkingsticks are approximately 4-5 inches (10-12 cm) in length. Their heads are elongated and oval shaped, with thread-like antennae and chewing mouthparts for eating plant material. These walkingsticks are brownish in color, and have six legs, which is a characteristic of all insects. Male Vietnamese walkingsticks have a full set of wings, while females have no wings.
About half a year
In the wild: Variety of foliage
At the zoo: Primarily blackberry bramblele
Reproduction occurs mostly by parthenogenesis, or asexual reproduction. As a result, males in this species are rare. The female drops hundreds of seed-like eggs to the forest floor, which hatch within a few months. Vietnamese walkingsticks go through an incomplete metamorphosis, so nymphs look similar to their parents.
Nymphs mature to their adult form in three months, after which time they are able to reproduce. Vietnamese walkingsticks are short-lived, surviving only 3 to 4 months after reaching adult size.
Primarily nocturnal in behavior, Vietnamese walkingsticks remain virtually motionless throughout the day. Their main predators include birds and small mammals. The primary defense of this walkingstick is its brownish color and stick-like appearance, which enables it to look like a twig of the host plant and blend into its surrounding environment. It may also freeze in place, or sometimes even rock back and forth to mimic a twig shaking in the breeze.
Female walkingsticks lay eggs in a number of interesting ways, depending on their species. Some randomly scatter their eggs, others conceal them, while others bury their eggs. Other species lay eggs in a more forceful way. As an example, one of the most prolific egg layers, the giant prickly walkingstick, can produce up to 1,000 eggs. When she's ready to lay, she quickly flexes the tip of her abdomen underneath her body, tossing the eggs below her head. Another species of walkingstick, Cyphocrania gigas, can eject her eggs almost 20 feet (6 m). For both species, spreading the eggs around this way reduces predation on their eggs and ensures food availability for their offspring!
Location at the Zoo
Woodland Park Zoo does not currenlty have Vietnamese walkingsticks on display. However, Bug World does display certain species of walkingsticks. You'll go "buggy" while viewing exciting seasonal displays that take you on a journey to different bioclimatic zones around the world. You may come face-to-face with recycling cockroaches, assassin bugs, web-spinning spiders or scuba diving beetles to name only a few. The only way you'll find out which bugs you'll encounter is by visiting Bug World. Don't miss it!
Numerous species of walkingsticks are popular in the pet trade. Since they are nonnative insects and could be considered plant pests, it is illegal to transport any stick insect without the proper permits. If you are considering housing these animals for use in your classroom or for pleasure, make sure to contact the U.S. Department of Agriculture for information regarding keeping walkingsticks as pets.
Vietnamese walkingsticks are common in the wild. Human-caused changes in land use are escalating, and this affects the natural habitat required by walkingsticks and other animals for survival. Vast forests are being removed for timber or other paper products, and industrial emissions are polluting water and air resources. Additionally, habitat is rapidly converted by expanding human communities and agricultural needs. It's only a matter of time until many insect species populations will become severely reduced, or eliminated.
Humans need insects. Often unnoticed, walkingsticks and other insects are essential for maintaining the balance in nature and health of the living world. Here are only a few of the benefits insects provide:
- Bees, butterflies and other insects pollinate wild plants and our crops, ensuring the production of seeds and fruits required for the continued survival of plants and animals.
- Earwigs, beetles and other insect scavengers clean up the environment by consuming decaying plants and animals. Nutrients are recycled back into the soil, helping future generations of plants to grow.
- Many species of carnivorous beetles, ants and wasps eat other harmful insects that damage or destroy our crops and spread disease.
- Burrowing insects aerate and enrich the soil.
- Insects are a source of food for animals, including humans!
- Insects produce products used by people, including honey, beeswax, silk and dyes, to name only a few.
How You Can Help!
The effort to save animals and their habitat requires cooperation and support at the international, national, regional and individual levels. You can help in this cause. Join and become active in Woodland Park Zoo and other conservation organizations of your choice. To conserve habitat for sowbugs, pillbugs and other arthropods, reduce your use of pesticides and herbicides, and work to preserve vegetation in your neighborhood and in tropical regions.
Contact Woodland Park Zoo at firstname.lastname@example.org to find out how you can support conservation efforts at the zoo. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.
Sources and Suggested Reading
Borror, Donald Joyce. 1974. A Field Guide to Insects: America North of Mexico (Petersen Field Guide Series). Houghton Mifflin Company, Boston, MA. 404 p.
Nuridsany, Claude & Marie Perennou. 1997. Microcosmos. Stewart, Tabori & Chang, New York, NY. 160 p.
Gaffrey, Michael. 1994. Secret Forest. Golden Book, Western Publishing Company, Inc., Racine, WI. 31 p.
Mound, Laurence. 1990. Insect (Eyewitness Book). Alfred A. Knopf, Inc., New York, NY. 64 p.
Zoobooks. 1994. Insects. Wildlife Education Ltd., San Diego, CA. 18 p.