Habitat
Tropical forested regions |
Physical
Characteristics
Female Australian walkingsticks
reach approximately 5 inches (12 cm) in length, while males are much
smaller, attaining a length of about 4 inches (10 cm). These walkingsticks
have elongated, oval-shaped heads covered with spines. They also
have long antennae and chewing mouthparts for eating plant matter. Females
are light tan in coloration with long, thick bodies, and have
a pair of non-functional wings. Males are dark brown in color
and have a full set of functional wings. A male's forewings
are dark in color, but the inside wings are often brightly colored
and can be used as a warning to predators. When the wings are
rapidly opened, the flash of color may startle a predator long
enough for the male walkingstick to escape. |
Life
Span
Adult life span is seven to 10 months |
Diet
In the wild: Certain species of eucalyptus
At the zoo: Blackberry
bramble |
Reproduction
There is no courtship between male and female Australian walkingsticks.
The male is attracted by the female’s scent. Once a female
is located, he crawls onto her back, bends his abdomen around and
mates with her. Sperm is transferred in a packet called the spermatophore.
Mating can take hours, with males often "hanging out" on
the female's back. Eggs are gray and tan in color. A female
can lay up to 1,000 eggs in her lifetime.
Males do not have to be present for females
to reproduce. Females are capable of parthenogenic (asexual) reproduction.
If males are present and the female mates, eggs hatch within a few
months. Parthenogenic eggs take longer to develop. Newly-hatched
nymphs are approximately 0.8 inch (2 cm) in length.
Life Cycle
The metamorphosis of the Australian walkingstick is incomplete
(nymphs look similar to their parents). It takes approximately three
to four months for a nymph to reach adult stage. During this time,
Australian walkingsticks go through six or seven molts.
Australian walkingsticks are nocturnal, remaining
mostly motionless during the day. Their enemies include birds and
small mammals. If a predator approaches, walkingsticks will freeze
in place, or sometimes even rock back and forth to mimic a twig shaking
in the breeze. Their brown color and stick-like appearance also help
them to look like a twig of the host plant and blend into their environment,
camouflaging their presence from predators.
Egg Toss
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!
|
Fascinating
Facts
- The
order name, Phasmatodea, originates from the Latin word "phasma,"
meaning ghost. This is due to the excellent camouflage ability
of
walkingsticks!
- Stick insects have both claws and
sucker pads on their feet, which enable them to walk straight
up a vertical surface!
- Australian walkingstick nymphs mimic
scorpions to scare off predators!
|
Amazing Australian
walkingsticks are currently on view at Woodland Park Zoo's Bug
World. 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!
Australian
walkingsticks are not endangered. 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 walkingsticks and other insects, reduce your use of pesticides and
herbicides, and work to preserve vegetation in your neighborhood and
in tropical regions.
Contact Woodland
Park Zoo at webkeeper@zoo.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.
For Kids!
Mound, Laurence. 1990. Insect (Eyewitness Book). Alfred
A. Knopf, Inc., NY, NY. 64 p. |
Classification
and Range
