The book “Curious Encounters with the Natural World” tells the story, among other things, of how authors Michael Jeffords and Susan Post met. The married Champaign entomologists, who recently released another book, “Butterflies of Illinois: A Field Guide,” first met when she was his entomology student and got to know each other as they went on trips to photograph together. “We would go out on junkets, exploring all around,” Post said.

Post and Jeffords, who have been married 37 years, are also antique collectors. They used to have a shop in Mahomet. “We have an eclectic collection of things,” Jeffords said.

Jeffords is the retired education/outreach director for the Illinois Natural History Survey and was staff photographer for the Illinois Steward magazine. His interest in insects started 61 years ago, as a 9-year-old. Post has been fascinated with insects since age 8, when she took it on as a 4-H project. “This was before Title IX,” she said, explaining that girls typically did projects like cooking and cleaning. “I wanted to join the boys’ club. My mom suggested entomology. Who knew this would be my career? It takes us to wonderful places. It’s taught us to observe more and sharpened our focus.”

The couple’s travels have taken them to every continent except Antarctica. They have been to Africa four times, India, South America, Australia and the Falkland Islands, where they saw an extremely rare butterfly, the Queen of Falklands Fritillary. “These are butterflies you sort of have on your wish list,” Post said.

Other times unexpected sights surprise them. In southern Illinois, the couple saw hundreds of swallowtails in a field of clover. “You never know where it’ll be,” Post said. “There’s never a dull moment.”

 

Collaborating on the book

Jeffords and Post started working on the butterfly book in 2010, when the first edition went out of print. They decided they wanted to make the guide more user friendly, with fewer technical terms. In the front of the book there is a quick identification guide with topside photos of all of the species that have been found in Illinois; in the back are underside photos. “(Editor Danielle Ruffato) painstakingly cut those out on the computer,” Post noted. “A lot of species look alike. This is a true field guide.”

“It has no technical jargon,” Jeffords added.

It took about five years to compile all of the book’s research. Post and Jeffords visited 30 Illinois sites about 50 times to find the 102 species that have been seen in Illinois. They spent three years traveling to 21 sites to identify every species they saw for a research project. “You’ve got to make sure you don’t count some twice,” Jeffords said. “There are about 75 (species) you see regularly.”

In the Grand Prairie biome, in which East Central Illinois is located, a butterfly spotter can see up to 30 species in one day. “That would be a really good day for us,” Jeffords said. “It’s great to have a field guide specific to a certain area. In the book, we try to answer every question we would ask.”

Cabbage white butterflies, a common crop pest, was introduced to the United States from Europe in the 1800s. Most other butterfly species are native.

Adventure often played an important role in the couple’s travels. “Some of the places were just awful trying to go through,” Jeffords said.

“The clinging seeds were so bad we had to wear Tyvek suits,” Post said, referring to the protective polyethylene suits.

At the Richardson Wildlife Area in northern Illinois, the vegetation was so dense that Jeffords and Post had difficulty walking through it. Fortunately, the butterflies could be seen along the perimeters. “They like to stick to trails just like we do,” Post said.

“They also like to have a little room to maneuver,” Jeffords agreed.

Post said that the most frustrating part of her work is when the wind is blowing and she is trying to make sure a subject she’s photographing is in focus.

“For me, it’s when stuff should be there, and it’s not,” Jeffords said.

The couple shared author credits with their friend, Jim Wiker of Athens, Ill., an amateur butterfly enthusiast who has his entire basement set up like a museum and is a research associate of the Illinois State Museum and an affiliate of the Illinois Natural History Survey.

According to the couple, one of the best places for seeing butterflies is in the Iroquois County State Wildlife Area near Beaverville. “There are a lot of interesting habitat over there,” Jeffords said.

Another favorite locale is the Sand Ridge State Forest in Mason County, which is the site of what Jeffords calls “one of the great phenomenons.” In June every three or four years, millions of hackberry emperor butterflies, a small brown species, converge around the ponds there. “It’s absolutely amazing,” Jeffords said. “We get pretty excited,” Post added.

Jeffords and Post are also the authors of “Exploring Nature in Illinois: A Field Guide to the Prairie State.” The couple declined to write a guide similar to their butterfly book about moths, of which there are nearly 2,000 species in Illinois.

 

Why butterflies?

So why are butterflies important enough to study? “Butterflies are pretty good indicators of habitat quality; when they disappear, you have to wonder,” Jeffords said.

Some of the plants that butterflies feed on include parsley and pipe vine, depending on the species. The best-known food plant is milkweed (for monarchs), of which there are 25 to 35 species in Illinois.

The United States has about 700 species of butterflies and skippers; Illinois has about 100 species of butterflies and 60 species of skippers. “We have quite a good diversity,” Jeffords said. “But you’ve got to sometimes work to find the odd ones.”

Although some species like the monarch migrate in late August and early September, most do not. “Monarchs can’t survive the winter here,” Jeffords said.

Some species live for only a few weeks, while monarchs live eight to nine months. Overwintering species emerge and lay eggs in the spring, living about six or seven months.

Over the last 15 years, though, the number of species at the state forest have declined. “We have seen the landscape changes, and they have not been for the good,” Post said. “That’s disappointing.”

 

Bringing awareness

Part of the couple’s mission is to educate the public. “We talk about things not to do,” Jeffords said.

“It’s not just planting pretty flowers,” Jeffords said. “Your yard needs to be a little bit wild. You need water and food plants for the larvae. In late summer/fall, monarchs don’t need milkweed anymore; they need energy sources for their migration.”

Some of these nectar sources include late-season asters and blazing star (Liatris). “Keep stuff blooming all season,” Jeffords advised. “Flowers like petunias die out in the heat of summer, so you should keep things going toward frost time.”

So why are butterfly numbers dwindling? “It’s not an easy answer,” Jeffords said. “They need habitat diversity to function well.”

Roadsides being mowed excessively is part of the problem, the couple says. “Five or ten feet along the road is fine,” Jeffords said. “You just don’t see a lot of blooming plants like alfalfa anymore. There’s not a lot to nectar on.”

There are steps people can take to attract butterflies. “Don’t clean your garden up in the fall,” Post said. “You’re taking out your butterfly population. You don’t know they’re there. It’s OK to be a messy gardener.”

“They need late season food sources and habitat structure to overwinter,” Jeffords said.

An ideal butterfly habitat for overwintering includes sites that are protected, like a brush pile. “The butterfly houses are cute but don’t work,” Jeffords said.

The couple often gives talks about butterflies and leads field trips for groups of about 15. “There’s lots of interest,” Jeffords said.

 

Spotting butterflies

At night, butterflies can be found under leaves. “It’s easier to find them at night,” Jeffords said.

The couple cautions that you shouldn’t expect to see many species in a short amount of time. “You’ve got to be patient,” Jeffords said.

“You never know what you’re going to see,” Post said.

Butterflies lay their eggs on the food plant appropriate to their species. “If they choose poorly, the larvae are dead,” Jeffords said.

While monarch females usually lay a single egg on a milkweed plant, a hackberry female will lay eggs in groups of several hundred under hackberry tree leaves. Interestingly, fritillary butterflies, which lay their eggs on wild violets, will even lay them where violets used to be. “We still are amazed,” Post said. The regal fritillary is listed as threatened in Illinois.

Butterflying has been gaining popularity as a hobby, especially among birders. “The same skills transfer,” Jeffords said. “A lot of birders are listers; how many species can I see?”

The Internet has made the hobby easier, too, since information can more quickly be found. It’s also easier to post a photo taken about a given species and ask questions of others in the community. “If nothing else, at its simplest level, you can just enjoy looking at them,” Jeffords said.

In the early days of butterfly identification, males and females were often described as two different species because they were dimorphic, meaning they were a different size and had wing patterns that varied widely between the sexes.

Many Master Naturalists serve as volunteer butterfly monitors. Unlike birding, butterfly spotters don’t have to be up at the crack of dawn; the couple prefers to go out during the ideal time of between 10 and 11 a.m. on days that aren’t windy. “It’s an interesting pastime,” Jeffords said. “You kind of know what to expect in certain places,” Post said. “A lot comes from experience and being out there all the time.”

Post and Jeffords recommend close-focusing binoculars for those who want to look for butterflies. “A lot of them (butterflies) are the size of my thumbnail,” Jeffords explained.