While much of the country was officially mourning the death of Ronald Reagan last June 11, Carol Cook was out in the rain picking leaves from as many purple loosestrife plants as she could find.
Cook is the project coordinator of the Indiana Coastal Restoration Action Team, a project of the Save the Dunes Conservation Fund in Michigan City. Last April she worked with Joy Marburger of the National Park Service’s Great Lakes Research and Education Center to pull together a daylong forum on the exotic invasive weed purple loosestrife (Lythrum salicaria), whose bright flowers are ubiquitous in late summer–a bad thing, since they crowd out native plants, deprive animals of food and habitat, and disrupt and impoverish wetland ecosystems. The forum brought in experts from Wisconsin (the state’s a national leader in purple loosestrife control) and attracted locals including Douglas Mohlke, a horticulture instructor at Indiana Westville Correctional Facility.
According to a University of Minnesota extension publication, “A single purple loosestrife plant with multiple stems can produce between one and two million seeds that are easily dispersed along rivers and waterways.” So don’t even think about trying to pull it all up. A likelier solution in places like northwest Indiana, where there are large stands of the weed, is to sic another exotic invader on it.
As it happens, two beetles native to Germany, Galerucella calmariensis and its practically identical cousin Galerucella pusilla, feed almost exclusively on purple loosestrife leaves. U. S. Department of Agriculture tests have found that there’s little danger of the beetles themselves getting out of hand, and they’re being introduced gradually by groups ranging from 4-H troops to state governments.
At the April forum Cook, her boss, Tom Anderson, and Brian Kortum, a natural resources specialist employed by NiSource (the local utility’s holding company) came up with the idea of jump-starting local beetle populations by raising them in a favorable environment for a few weeks, then distributing their hungry offspring to willing wetlands owners in northwest Indiana–the National Lakeshore, the Conservation Fund, and NiSource itself. The ultimate goal is to control the purple loose-strife, not eradicate it, says Anderson. “If the plants disappear from an area, the beetles would disappear too, and then we’d have to start all over” when the plant cropped up again.
Ironically, in the early 70s the Save the Dunes Council urged Congress to add a parcel of land to the Indiana Dunes National Lakeshore precisely because it was covered with purple loosestrife–the plants were considered a local landmark. The weed’s gone from ornament to outlaw in short order. Once sold in nurseries, it’s now illegal to obtain or possess in Indiana unless you have a permit from the state Department of Natural Resources. Armed with one, and with a two-year, $5,000 grant from the NiSource Environmental Challenge Fund, Cook, Anderson, and Kortum started assembling their attack.
In late April the trio dug up 87 root crowns and took them to the Westville Correctional Facility. There Mohlke and about 20 of his students potted each plant in a “rearing unit”: a five-gallon pot topped by a tomato cage covered with see-through fabric to keep beetles in and predators out. Helping out as a volunteer, Kortum sewed the covers. He’s making more for the larger assault the group plans for this summer.
Early in May they collected the starter beetles in a wetland where they’d already been introduced, an hour’s drive east in Lakeville. That’s a cost-effective alternative to buying them from the USDA for a dollar a head, but it didn’t seem so effective at first. “We touched the first plant and all the beetles fell to the ground,” recalls Anderson. “We collected maybe five of them in the first 15 minutes.” Eventually the humans got the knack and collected 2,000 in two hours, using specially adapted water bottles. “Now,” says Anderson, “we’re some of the most experienced beetle collectors in the state of Indiana.”
Cook became fond of the small brown beetles, which she described as “very gentle….They crawled all over me. They’re charming.” At Westville the students added 10 to 12 of the collected beetles to each rearing unit, where they reproduced and ate like crazy. “When their eggs hatch,” says Mohlke, “each unit can get 1,000 new beetles.”
Even though heavy rains drowned several rearing units, the plan worked almost too well. Spring-dug purple loosestrife doesn’t grow as vigorously as crowns dug the preceding fall and, ever voracious, the beetles ate faster than the plants could grow. Several times Mohlke gathered extra leaves for them along a creek near his home.
By early June, 30 rearing units full of beetles were ready to go–more than ready. Cook brought half a dozen units from Westville to the front yard of the Conservation Fund’s office. They were scheduled to go to the National Lakeshore on Friday, June 11. Then the national day of mourning was declared to honor Reagan and all federal offices were closed.
Galerucella don’t stop eating for anyone, not even a dead president. Cook found herself in custody of six miniature ecosystems ready to undergo a catastrophic population crash right in front of her office. By the time the National Lakeshore was to reopen on Monday, the beetles would have skeletonized their plants and starved to death.
Cook did as Mohlke had done before her. No one in northwest Indiana is ever far from purple loosestrife, and Cook knew where it grew near her home. She went out in the rain, pulled off the leaves, stuffed them in large bags, drove over to the office, and fed the hungry beetles. When the mourning and the weekend were over, the plants were set out in the Lakeshore at recorded locations. In a few years it should be possible to see whether the beetles have done as much useful damage in the wild as they did in the greenhouse.
Art accompanying story in printed newspaper (not available in this archive): photos/Randy Westbrooks, Norman E. Rees.