Animal Fact Sheets

GIANT WATER BUG

(Abedus herberti)
 

Classification and Range

Water bugs are members of the class Insecta. The giant water bug belongs to the family Belostomatidae, one of 50 families in the order Hemiptera. Members of this order are considered "true bugs." There are approximately 100 species in the family Belostomatidae that live primarily in North America, South Africa and India. In North America, Abedus herberti is located throughout Arizona and portions of adjacent states and Mexico.

The giant milliped lives in both tropical and arid coastal forests of eastern Africa.

Habitat

Clear, freshwater streams and ponds, preferring those with aquatic vegetation.

Physical Characteristics

Giant water bugs are approximately 1.5 inches (3.8 cm) in length. Some species grow as long as 4 inches (10 cm). They have one pair of tiny, almost inconspicuous antennae located snugly below their compound eyes. The giant water bug's mouthparts are elongated into a beak-like structure designed for piercing and sucking.

The body is brown, flat and oval, giving them an appearance similar to that of a cockroach. The front legs are raptorial (grasping) to seize prey. Their other two pairs of legs are flattened and fringed with hair to increase their surface area. These legs are used like paddles for propulsion. Adults have two pairs of wings, but they rarely fly unless forced to by unfavorable water conditions or lack of an adequate food supply.

The posterior end of a giant water bug has two retractable, semi-cylindrical appendages which, when held together, form a breathing tube. This tube is used for underwater breathing. When in flight, air is exchanged through small openings of the respiratory system called spiracles.

Life Span

One year or longer.

Diet

In the wild: Larvae eat small aquatic invertebrates, while adults prey on any small animal they can handle, including insects and other aquatic invertebrates. They also hunt vertebrates such as tadpoles, salamanders and small fish. Grasping and holding prey with their powerful forelegs, giant water bugs thrust their sucking mouthparts into their prey.
At the zoo: Crickets

Reproduction

During mating, the female approaches the male and begins the courtship ritual which involves sparring with one another, and grasping in the air. To ensure that he is the father, the male will copulate with the female and allow her to lay the eggs on his back. He will only allow her to lay a few eggs after each mating. This ritual continues until the male's entire back is covered with approximately 150 eggs. The male then takes care of the eggs, frequently exposing the eggs to air to prevent the growth of mold or other aquatic organisms. Eggs take approximately three weeks to hatch. After all the eggs have hatched, the glue attaching them to the male's back deteriorates and the egg cases fall off.

Life Cycle

Giant water bug offspring are pale yellow in color for a few hours after birth, then assume their normal, darker color. Offspring spend much of their time near the water's surface, so they can occasionally stick their backsides out of the water to breathe. Nymphs have small tubes located on their hind end. These tubes act like snorkels and carry air throughout the animal's body. Metamorphosis of the giant water bug is incomplete, so nymphs look similar to their parents. Nymphs go through five instars (various forms of arthropods between molts) over eight to 10 weeks before becoming adults.

Ambush Hunters

Giant water bugs are ambush hunters, lying motionless and waiting for their prey. Predators of giant water bugs include birds, fish and other aquatic predators. When sitting motionless, giant water bugs resemble dead leaves. This allows them to hide from both potential prey and possible predators. However, their best defense is to escape and hide when alarmed.

Adult giant water bugs capture larger prey species by using their clawed front feet and chemicals which are injected into the body of the prey. The enzymes turn the preys insides into liquid, which the giant water bug can suck up.

Location at the Zoo

Fantastic giant water bugs are periodically on display 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!

Conservation Connection

Giant water bugs are currently not endangered. Human-caused changes in land use are escalating, and this affects the natural habitat required by giant water bugs 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.insect species populations will become severely reduced, or eliminated.

Humans need insects. Often unnoticed,giant water bugs 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 giant water bugs 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.

 

Giant Waterbug Fascinating Facts

  • Like terrestrial insects, these bugs respire through spiracles. When submerged for long periods of time, giant water bugs carry a temporary external air supply in the form of an air bubble. The bubble is in contact with the bug's spiracles located between their wings and their abdomen's upper surface. The air bubble works to extract oxygen from the water!
  • Giant water bugs are sometimes called "toe biters" because, in self-defense, they will bite people wading or swimming in the water!

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 and Marie Perennou. 1997. Microcosmos. Stewart, Tabori & Chang, New York, NY. 160 p.

For Kids!

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.

 
 
 
 

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