Dr David Pearson an ecologist and conservation biologist at
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Dr. David Pearson, an ecologist and conservation biologist at Arizona State University

June 8, 2010
Dr. David Pearson, an ecologist and conservation biologist at Arizona State University (ASU), uses tiger beetles as bioindicators in his research. A bioindicator is a species that serves as a representative sample of its ecosystem and a monitor of environmental change. Tiger beetles make excellent bioindicators because they are highly sensitive to changes in their environment. Tiger beetles are a type of arthropod that are found almost everywhere on earth. They stand out because of their bright colors and interesting markings. [One of six related images. See Next Image.]

More about Tiger Beetles: Tiger beetles (family Cicindelidae) are a type of arthropod, a group that includes all insects, crustaceans, and arachnids. There are about 2,300 species of tiger beetles. With the exception of Antarctica, Tasmania and a few of the most remote oceanic islands, tiger beetles are found everywhere on earth where there's land.

Tiger beetles live primarily in tropical areas, but the United States is home to 120 different species. There are 36 species living in the state of Arizona alone! Eighteen different species live in the Sulphur Springs Valley in southeastern Arizona--one of the highest concentrations of species in all of North America.

Most tiger beetles are brown or green with stripes, but some species are stunningly decorated in metallic green, brown, maroon or purple, often with stripes or spots. They vary greatly in size. The smallest species lives in Borneo and is about the length of a housefly. The largest lives in southern Africa and can measures up to 45 millimeters. Species found in Arizona range from 10 to 25 millimeters in length.

All tiger beetles have long, thin mandibles shaped like sickles, which help them capture prey. The beetle larvae use their mandibles to dig tunnels in the ground, where they wait for small insects to pass close enough for capture. The larvae stay in their tunnels from one to three years before emerging as adult beetles.

Tiger beetles are swift. An Australian tiger beetle species is the fastest running of all arthropods. It can move 9 kilometers per hour (5.6 miles per hour). Tigers use this speed to capture prey. All desert tigers use their excellent eyesight to locate prey, and their amazing speed to run it down. (Year of image: 2000)

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