The vacant lot along the edge of Toy Road, a side street off Route 22 in Churchville, looks at first glance like a collection of weeds and shrubs, but those weeds are teeming with monarch butterfly caterpillars.
Lisa Nowakowski, a self-taught entomologist and the operator of the Lisa's Enviroshows environmental education programs, checks the wide green leaves of the milkweed, a vital food source for monarchs. She has to step carefully to avoid the poison ivy that also grows in the lot.
The Bel Air resident finds a bonanza of the yellow, white and black-striped caterpillars, ranging in size from about half an inch to an inch and a half, munching on the milkweed leaves. The leaves also shelter tiny white eggs that are the size of the head of a pin.
"It's a beautiful insect... at all life stages," Nowakowski, 70, said.
Monarch eggs and caterpillars can be found on patches of milkweed throughout Harford County at this time of year, going from egg to caterpillar to chrysalis to a brightly-colored butterfly with orange and black wings.
Adult butterflies migrating to their winter hibernation sites in Mexico lay the eggs as they travel. The new butterflies that hatch from chrysalises in September and October will also head south.
"No matter where they are, they need that milkweed," Nowakowski said, noting it is critical to preserve as much milkweed as possible.
A sign at the edge of the Toy Road lot indicates it is for sale for commercial development.
"If we don't have enough clean milkweed, we're going to lose this species," Nowakowski said.
Butterflies, along with honeybees, are key pollinators for wild plants and crops. The adults feed on nectar produced by flowers.
"Just about anything that lands on a flower is a pollinator," Nowakowski said.
Millions of monarchs nestle in trees in the forests of central Mexico each winter, but they are under threat from global climate change, logging in their winter forests and loss of food sources in the U.S. and Canada, according to the World Wildlife Fund.
The species is listed as "near threatened" on the WWF's website meaning they could "qualify for a threatened category in the near future."
Monarchs are also at greater risk for deadly diseases if too many larvae occupy one milkweed leaf, according to Nowakowski, who said only one female should lay eggs on each leaf.
"That's why it's so important to preserve the milkweed," she said. "It's the only thing they're going to lay eggs on."
Monarchs migrating from east of the Rocky Mountains usually head to Mexico, and those west of the Rockies head to California, Frank Marsden, naturalist and program director at the Eden Mill Nature Center in Pylesville, said.
Eden Mill officials have created a 10-by-20-foot monarch habitat near the classroom building so staff and volunteers can monitor the butterflies and visitors can see them go through their life cycles, starting with the eggs.
"It's just an amazing world," Marsden said. "You can sit there for hours and study them; it's like its own little botanical garden in a 10-by-20 area."
Marsden noted milkweed has no value other than as a food source for monarchs – the plant is poisonous to humans and other animals, so monarchs are protected from predators when they are on milkweed.
He encouraged home gardeners to plant milkweed on their properties, farmers to plant it on the edges of their fields and Harford County officials to plant it in highway medians.
"This is what we can do to help bring their numbers back," he said.
Eden Mill staff have, in recent years, been monitoring monarchs at the Nature Center and tagging them to follow their migrations.
The nonprofit group Monarch Watch provides the tagging materials, while the data is sent to the University of Minnesota's Monarch Larva Monitoring Project.
Marsden counted 54 chrysalises when he checked the habitat on a recent morning.
He said staff are "still seeing plenty of caterpillars," and "every day we see more and more monarchs hatching."
The tagging gear only arrived recently, so the staff was not able to track the groups that have already hatched, according to Marsden.
"We have the potential to do 50 or 60 of them in the next week or two," Marsden said of the newest adults. "We just have to be there when Mother Nature says they're hatching."
He wants to recruit a group of about 10 volunteers, who would work in teams of two, to monitor the monarchs on a regular basis during the 2017 season. One person on the team would monitor, and the other would record the findings.
The group of "citizen scientists' would do work similar to a volunteer group that monitors wood ducks at Eden Mill, according to Marsden.
"That's the best way to create stewardship of the environment, to have folks involved in it and to understand it," Marsden said.
Anyone interested in volunteering should call Marsden at Eden Mill, 410-836-3050. Visit http://monarchwatch.org for more information on conservation programs for monarch butterflies.