Ask the Times
Q: Where have all the fireflies gone? I don’t see them around like I used to.
A: Ashley Dowling is big into little things. He’s an expert, in fact, one of the few in his specialty in North America, and he does his work at the University of Arkansas. We didn’t know that when we called him to ask if the lightning bug population has declined. All we knew was that he was an entomologist, and, unlike most of the insect guys at the UA, he wasn’t into agricultural pests.
Dowling’s expertise is in mites, the most diverse of all arachnids, little creatures that he says play “a very important role in the ecosystem.” They decompose leaves, their aquatic larvae may keep insect populations under control, and they are water-quality indicators because of their sensitivity to nitrogen.
Dowling doesn’t focus entirely on mites. He and his students have been looking into arthropod (crustaceans, insects, arachnids) biology of the Ozarks, the Arkansas River Valley and the Ouachitas.
The Ozark Highlands have a “unique sort of geological history,” Dowling said. They are among the oldest features of North America, rising up “as a big dome more than a billion years ago.” The area’s plant and animal populations are wildly diverse — nearly as diverse as the Smokies’ and other mountain systems’ — and little studied.
“What we think is that during glacial times, the Interior Highlands [the Ozarks] stayed a stable landscape,” Dowling said. It has kept its head above water for eons — maybe around 300 million years or so — promoting a long-time home for flora and fauna, a stable temperate forest system. There are 110 species in Arkansas’s portion of the Interior Highlands that occur nowhere else. “Every time we collect, we tend to find new things,” Dowling said, in the never-logged glades and diverse Ozark canyons, “amazing plant and animal communities.”
Back to mites. As arachnids, mites can’t fly, so they hitch rides on other animals, including bugs and birds and mammals. If you’ve ever looked too closely into a bird’s nest, you’ll know there can be thousands of them, living in the nest, not because you can see them, but because they’ll jump onto your face looking for a blood meal. The smallest mites — those that fit 12 to the period at the end of this sentence, or smaller than 70 microns — are plant feeders. Dowling says he and his students have also found mites that are the world’s fastest animals for body size, and are a little miffed that someone else has published a paper identifying a slower mite as the fastest. They hope to remedy the scoop with their own published paper.
Dowling said half of his students are focusing on arthopod biodiversity projects and the other half on mite-focused projects, the latter with a National Science Foundation grant worth $720,000. He’d like to see the UA hire other biologists whose focus is on arthropods. “We’re very crop-centric here,” he said.
But the question was about fireflies. There are more than 100 species of fireflies in the United States, Dowling said; there may be four or five species flying around at one time in a yard. There are fireflies that blink synchronously in the Smokies. There are female fireflies that lure in males by imitating their mating blinks only to devour the unsuspecting suitor. Dowling said he is aware of concerns about firefly populations, but “all arthropods go through periods of population booms and busts so there are always some years where you see lots of them and some where you don’t see much at all.”