Marla Garrison, McHenry County College Biology instructor, is the author of "Damselflies of Chicagoland, A Photo Field Guide" recently published online by the Field Museum of Natural History in Chicago as part of their Chicago Wilderness Series of Rapid Color Guides.
Garrison, of Naperville, who worked with the Illinois Butterfly Monitoring Network for seven years, said she got hooked on damselflies after joining the Dragonfly Society of the Americas and meeting expert odonatist, Bob DuBois, at the Great Lakes Odonata Meeting. Odonata is the order of insects to which dragonflies and damselflies belong. DuBois, author of several regional damselfly field guides, inspired her to write her own field guide covering Chicago and surrounding suburbs.
Bil Alverson, a botanist at the Field Museum, contacted Garrison about publishing her guide on their website which contains a variety of resources and keys to assist local naturalists.
"I'm thrilled that the guide is available to all who wish to view or download it. It was a main goal of mine to make the information in the guide free and accessible for anyone who was interested in learning about these tiny, beautiful members of their community," she said. "Working with the Field Museum has been a rewarding experience and a privilege," she said.
Three years ago, Garrison began photographing in situ the 39 species of damselflies found in the Chicago area. Rain or shine she stalked them in forest preserves, state parks, nature preserves, and private lands for close-up views of these narrow-bodied, pin-sized insects, using a Nikon D300 camera with a 105 mm Macro VR Nikor lens. Two of the species are actually new discoveries for our area, including the Lilypad Forktail, which she found in Lake Defiance at Moraine Hills State Park, and the Springwater Dancer, found in Bluff Spring Fen, Elgin.
"I was army crawling through grass and slogging through wetlands up to my waist," Garrison said, adding that she was overwhelmed at times by leeches, chiggers, mosquitoes, stinging nettles and swimmer's itch.
Not a single subject was posed or netted, and males and females of each species are depicted. Photos taken at multiple angles and of different individuals are featured in the guide, including dorsal, lateral and facial shots, age-related color changes and variable morphologies. A unique aspect of the field guide is a color-coded body length ruler and flight season tab.
Garrison said the primary purpose of creating the field guide was to provide citizen scientists a resource for identifying damselflies, a largely underreported group of insects.
"Damselflies can be indicators of water quality and water type," she said.
Garrison is currently working with DuBois and Alverson to develop an online dichotomous key for rapid identification. Next, she plans to write "Dragonflies of Chicagoland," the second in what she hopes to be a useful local guide series.
"Damselflies of Chicagoland" can be accessed on the Field Museum website at: