Discovering dragonflies results in a new book

Juneau biologists write the guide on Alaska's state insect

Posted: Sunday, August 07, 2005

Distant mountains

reflect in the jeweled eyes

of the dragonfly!

- Kobayashi Issa, 18th century Japanese poet

From a lunch cooler, Bob Armstrong gently pulled out a live dragonfly from a plastic bag and put in on a shore pine. The emerald dragonfly didn't move for two minutes.

A photographer was able to take several close-up pictures of the dragonfly from different angles before the dragonfly flapped its wings and disappeared.

"Dragonflies are good models," Armstrong said. "You capture them and put them in a small portable cooler to cool them down. Then you can put them on any branch of your choice and snap their pictures. Because they are cold-blooded, they need some time to warm up before they fly away."

For the past two years, Armstrong and John Hudson have been traveling all over the state identifying species of dragonflies and photographing them.

Their journey resulted in the book, "Dragonflies of Alaska."

Alaska is home to 32 specifies of dragonflies, including the delicate damselflies and big blue darners. Some of them even cruise in the Arctic.

New book "Dragonflies of Alaska" Juneau biologists Bob Armstrong and John Hudson will discuss their new book, "Dragonflies of Alaska," at 7p.m. Tuesday at Hearthside Books in the Nugget Mall.

Juneau, with numerous muskegs and small lakes, is a good place to observe dragonflies. Armstrong said Spaulding Meadows is the best place because of the many ponds along the trail to the meadows.

Hudson, a fisheries biologist, said the presence of dragonflies is an indication of good water quality because dragonflies feed on insects and need unpolluted water to breed.

The beautiful creature is Alaska's state insect.

Students who attended Alaska's public schools in 1993 selected a four-spotted skimmer, instead of a mosquito or a bumblebee, as the state insect.

"Dragonflies eat mosquitoes, one of the state's most annoying pests," a student who came to Juneau from Aniak to testify in front of the Alaska Legislature said at the time.

Armstrong and Hudson know that first-hand.

When they traveled around the state to work on the book, they didn't encounter a lot of mosquitoes when dragonflies were present.

"We got eaten alive by mosquitoes when there were few dragonflies," Armstrong said.

Dragonflies are aggressive predators, equipped with everything they need to catch an insect in mid-air.

Their four independently controlled wings allow them to hover, glide or move in any direction. Some species can fly 35 mph.

Their legs can extend to form a basket to catch prey and transfer it into their mouth.

Their huge eyes are compound, which means they are made up of many tiny eyes called facets. Each compound eye has up to 30,000 facets. A dragonfly can see as far as 42 feet, according to Emery Bernhard's book "Dragonfly."

Despite their fragile, translucent wings and tiny bodies, dragonflies can eat 300 insects in a day. In some countries, dragonflies are planted in rice fields to control mosquitoes.

"I don't know where they put it all," Armstrong said. "It probably takes a lot of energy to fly."

Dragonflies are swift hunters even when they live underwater. Larval dragonflies can extend the labium at lightening speed and grasp their target with hooks or teeth.

The larval dragonfly live for months or years before emerging as a winged insect.

Before mating, the male dragonfly seizes the female on or behind the head with his terminal appendages at the tip of his abdomen. He then flies off with her in tow, much like "a truck pulling a trailer," as Armstrong puts it.

People can easily see dragonflies mate at this time of year.

"Armed with a pair of close-up binoculars, a little patience, and a dry place to sit, you can see many fascinating aspects of their behavior," Hudson and Armstrong said in their book.

• I-Chun Che can be reached at

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