Zoology

Tiger Beetles



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Both adult tiger beetles and their larva are fierce predators. The adults use their sickle shaped jaws to catch unsuspecting insects. And the larva, living in tunnels with in dry dirt or sand, use their strong jaws to snatch passing insects while holding themselves in place with hooks attached to their 5th abdominal segment. They are called "Tiger" Beetles because of the ferocious way they attach and kill their prey.

Appearance

Tiger beetles (family, Cicindelidae, order, Coleoptera) have two sets of wings and are most recognized by their elytra, fore wings, which are armor-like. The elytra cover the smaller back wings that are used for flying. In a resting state, the elytra form a distinct line down the back. They are all basically the same shape and normal size is about inch long, with long antennae on their heads, long legs, narrow thorax (body section) and long elytra wings. However, the smallest tiger beetle lives in Borneo and is the size of a house fly while the larges lives in South Africa at about two inches.

There is quite a variation in the color and markings of tiger beetles. They can be found in violet, orange, brilliant green as well as grey and black. Some varieties come in an iridescent blue and metallic bronze color. Most commonly they have white spots over their grayish brown exterior. Closely related to ground beetles but are distinguished from them by their larger head than thorax.

Life Cycle and Habits

Females lay their eggs (up to three or four a day), in long burrows deep in the dirt, leaving each larva to its own burrow which enlarges as the larva grows. Adults mate soon after leaving the larva burrows. The adult tiger beetle lives a mere 6 week life span, the larva two years. The last stages of the beetles lives are at the end of the warm season.

Some varieties of tiger beetles are know to run five miles an hour. This is a phenomenal fete considering it's size. The fastest variety is the Australian tiger beetle which runs 5.6 miles an hour. In comparison, if the beetle were the size of a horse it would be considered to run 120 miles an hour. They are not easily caught because of their extreme alertness and quick action as well as the ability to take flight without notice.

Food Source and Habitat

Tiger beetles enjoy the heat of the sun and can be found during the day and among other places enjoy sandy shores of rivers and streams. However, different varieties can be found in various places such as the dessert, tropics, clay banks or wooded areas. In fact they live almost everywhere, excluding Antarctica, Tasmania and some remote islands.

They eat a wide variety of insects using their good eyesight and quick movement. Waiting patiently in camouflage then leaping at it's prey, clenching and crushing it with it's jaws. After drenching the insect with digestive fluid, it eats it at once. However, when chasing an insect it seems to pursue it in a stop and go fashion. The reason for this has just recently been discovered by scientists. The beetle looses it's sight when it accelerates, so it stops to see where the prey is and then starts after it again.

Larva simply eat for up to two years in their burrow before they emerge as full grown adults. These beetles have been known to bite humans, although it is a mere pinch.

The main enemies of tiger beetles, other than humans, are birds and lizards. While the larva can be eaten by birds, ants and wasps.

Endangered

Because of human behavior, the tiger beetle has been pushed out of and destroyed from much of it's natural habitat. When the dirt or sand where the larva live for up to two years is disturbed, they are destroyed. And so, they are considered "threatened" under the Endangered Species Act in many places.

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