Dragon and Damsel Adults: Are Back to Dazzle, Eat Mosquitoes
May 26, 2019 03:27PM
● By Sheryl DeVore
Photo by Janet Haugen
Dragonflies and damselflies are like the Tinkerbells of the wetlands. These tiny, winged creatures with descriptive monikers such as pondhawk and baskettail flit above water and vegetation from spring through fall in the Chicago region, providing a service to humans as they snatch mosquitoes and other insects in the air. However, their numbers are declining, not only here, but throughout North America, where at least 20 percent of dragonfly and damselfly species, collectively called odonates, are at risk, according to the Xerces Society.
Local volunteers have been monitoring odonates for 15 years to assess what’s happening. Monitors gather data on warm, sunny days between 10 a.m. and 3 p.m. and commit to walking the same route at least six times from early June through late September annually along specific wetlands, meadows and other habitats to record the more than 40 species of odonate species they see. Some of these species require specific habitats in which to thrive.
“Long-term data will help researchers know which odonate species are declining, as well as where they are present,” says Lalainya Goldsberry, assistant manager of living collections at the Peggy Notebaert Nature Museum, in Chicago. She coordinates the Illinois Odonate Project, which began in 2003.
Their preliminary data is showing a possible 57 percent decline in odonate observations in the Chicago region, Goldsberry says. Although all the data has not been processed yet, she says there’s cause for concern. “Odonates indicate the health of an ecosystem, and that ultimately affects us,” Goldsberry says. Habitat destruction, fragmentation and pollution could be among the causes for the decline of some odonate species. Volunteer monitor data also may help determine if restoration in natural areas is working,” she adds.
“Odonates have been on this Earth for 300 million years,” Goldsberry says. “Some back then were found with up to a 2.5-foot wing span. They were the largest insects to fly.” Their descendants today are much smaller. The largest dragonfly in the Chicago region, the common green darner, is about three inches long. One of the smaller damselflies, the eastern forktail, is less than an inch long.
One of the first things monitors learn is the difference between dragonflies and damselflies. Generally, a dragonfly holds its wings out, while the damselfly, typically a weaker flier, holds its wings back. Also, dragonfly eyes are closer together than those of damselflies.
Most of an odonate’s life is spent as a nymph under water. Some nymphs, for example, those of the federally endangered Hine’s emerald, seen in only one or two spots in Illinois, spend several years in the water before emerging to become adult dragonflies. “We see the adults for a couple weeks to a month, perhaps,” Goldsberry says. There’s a flurry of feeding and mating, and then they’re done. “The way they mate is pretty cool,” she adds, referring to a male and female attached to one another in a wheel or heart shape as they fly in tandem.
The female lays eggs in vegetation near water. The eggs hatch into nymphs that eat mosquito larvae and other aquatic insects. When it’s time to change into an adult with wings, the nymph crawls out of the water and climbs onto a plant stem. It then sheds its skin to become a young dragonfly.
Jim Wolf, who has monitored odonates at Bluff Spring Fen, in Elgin, for the past four years, says it didn’t take long for him to be fascinated by these creatures. When he began paying more attention to odonates, he noticed their varied behaviors and learned that the first to be seen in spring are green darners, which are among a few of the dragonflies in the region that migrate. Sometimes they’ll return as early as April or May to the area and still be seen in October.
Others are only seen for a short time and require specific habitats in which to live. One example is the ebony jewelwing damselfly, which flies in June. “They prefer wooded areas, with dappled sunlight and slow-moving water,” Wolf says.
In July, Wolf starts seeing calico pennant dragonflies. “They will stay stationery, guarding their territory, so they’re not as much as on the wing, and that gives me a better chance to watch them,” he says. “At the height of the season, it will be very busy. You’ll see five, six or seven species looking for their mates and chasing off other males. It’s amazing just how many different species you’ll see in one spot vying for the same area.”
In August and September, several different meadowhawk species appear, with adult males sporting a red abdomen. By the end of the season, Wolf likely has documented up to about 35 different species at his site. “Monitoring odonates is very calming,” Wolf says. “I just love being outside, alone, watching the dragonflies and damselflies.” He hopes his volunteer work can benefit the insects he loves. “What I’m doing is a small piece of the puzzle,” says Wolf. “It’s a cog in the wheel, and all the cogs will help scientists understand more about dragonfly and damselfly populations.”
Sheryl DeVore is the author of Birds of Illinois and Birding Illinois. She served as editor of Meadowlark: A Journal of Illinois Birds for 25 years and continues to write articles about birds and nature for national and regional publications. She can be reached at [email protected].
Finding and Attracting Odonates
Those that want to watch odonates from June through autumn should choose a habitat that includes open water with vegetation around it, where the insects can feed, hide and lay eggs, suggests Jim Wolf, an odonate monitor at Bluff Spring Fen, in Elgin.
To identify them, determine if it’s a damselfly or dragonfly and note the size, key colors of the abdomen, legs and face, and physical characteristics such as a forked tail or swelling at the end of the abdomen. Those living close to odonate habitat may be able to attract them to their yard.
Wolf has planted butterflyweed, liatris and other native prairie plants that provide habitat for insects that dragonflies eat. “Some of them come from a mile away from a pond. I’ve even had a small feeding swarm of darners,” he says.
For more information on odonates and volunteering to monitor them, visit IllinoisOdes.org.