Date: Fri 20-Sep-1996

Publication: Bee

Author: KAAREN

Quick Words:

Loosestrife-Beetle-Ellis

Full Text:

w/photo: Science Enlists A Beetle To Take On A Pretty Pest

B Y K AAREN V ALENTA

Purple loosestrife, the exotic invasive weed, which looks so lovely blooming

in the Ram Pasture during late summer, may finally have met its match.

Donna R. Ellis, a plant scientist at the University of Connecticut, received

state permission this year to release a species of European beetle that eats

loosestrife. Although only two test plots - at Haddam Meadows State Park and

on UConn's main campus in Storrs - were approved, others may follow next year.

In August 1993, when the Newtown Village Cemetery Association, which maintains

the Ram Pasture, mowed down the blooming loosestrife, a hue and cry went up

among many residents who thought the tall, spiky plant was beautiful.

Donna Ellis doesn't disagree. She doesn't expect - or even want - to

completely eradicate the loosestrife from Connecticut's countryside.

"There will always be purple loosestrife," Ms Ellis said. "That's the

situation in Europe, where it is one of many different native plants that

exist together. It's not dominant there."

But in Connecticut, with no natural enemies, purple loosestrife is

aggressively crowding out the native species - often plants that wildlife

depend upon - and changing the character of many habitats.

For nearly two centuries purple loosestrife has flourished in wet, sunny

places in the Northeast, becoming ever more plentiful over the years, so much

so that now it is almost everywhere. In a 1995 statewide survey of wetland

areas conducted by UConn staff, purple loosestrife was found in all counties

in the state but the primary areas of concentration were in the Connecticut

and Housatonic River watersheds.

"Waterways are being choked out and a lot of wildlife habitats are being

degraded," Donna Ellis said. "We hope to bring (purple loosestrife) down to a

level of about 10 percent of what exists now in Connecticut."

A tall, herbaceous perennial that can reach a height of about eight meters,

purple loosestrife ( Lythrum salicaria ) reaches maturity in three to five

years, producing as many as 50 stems per plant and as many as 2.5 million

seeds per year. The woody roots form a dense mat underground; the taproot

preserves the plant when the vegetation is mowed or supressed by herbicides.

Impossible to Kill

The seeds are very small, easily dispersed by air or water. Digging up the

plant is nearly impossible.

"Even if you just leave a piece of the root - a fragment - it will grow

again," Donna Ellis said. "A small piece of the plant left on top of the

ground will root itself. Seeds can be buried for years and will germinate if

the ground is disturbed."

In a biocontrol study which began this summer, two kinds of European

leaf-eating beetles, Galerucella calmariensts and Galerucella pusilla were

released at the two test sites after permits were approved by the state

entomologist, Louis Magnarelli, last February. The beetles eat purple

loosestrife and a related species, Lythrum alatum Pursh, which was not found

at any of the 300 wetland areas surveyed in Connecticut during 1995.

Scientists in 24 states have released the beetles or Hylobius

transversovittatus, a root-boring weevil, since biological control efforts

first began in the United States in 1992.

The concern with biocontrol is that the controlling organism itself might

become a pest. But advocates of the control effort say extensive studies were

conducted before the federal government decided that the insects could be

imported into the United States.

"The number of beetles released at a site depends largely upon the size of the

site," Donna Ellis said. "We released 800 beetles here at UConn and 1,600 at

Haddam Meadows. Winter mortality is a big issue - there can be as much as a 90

percent loss of the beetles from one winter to the next.

"Other insects also could eat the beetles or use it as a host to develop its

larvae," she said. "We anticipate those types of problems, but we hope that

eventually the loosestrife and the beetles will reach an equilibrium."

Fifteen states already have officially cited purple loosestrife as a noxious

weed, meaning that it cannot legally be imported or distributed. Connecticut

doesn't have a state noxious weed list yet and adding to the problem is the

fact that people who are unaware of the problems the plant is causing continue

to buy it by mail or at garden centers.

Consumers are often told that the plants are sterile, that they can't

reproduce, Ms Ellis said, but there can be cross fertilization if an

unsterilized plant is growing wild or cultivated someone else in the area.

"White Flower Farm took it out of its catalogue a few years ago, but it is

still being sold elsewhere," she said. "A major effort has to be made to

educate the public."

A State Purple Loosestrife Committee was formed in Connecticut in September

1995 to address these issues. Its membership is made up of representatives

from state and federal agencies, universities, the Connecticut Agricultural

Experiment Station, and several interest groups.

A Few Advocates

Despite the growing opposition, purple loosestrife does have advocates.

Because it is one of the few plants that blooms in late summer, when nearly

all the other summer annuals are dying back, some commercial beekeepers say it

is a valuable source for pollen.

Donna Ellis remembers the uproar in Newtown when the Ram Pasture was mowed

while the loosestrife was in flower. Former First Selectman Zita McMahon even

wound up asking that the property not be mowed until after the loosestrife had

finished blooming.

"I have a copy of the article which appeared in The Bee in 1993," Ms Ellis

said. "We came by again last year and observed the loosestrife when we did our

survey."

James Crick, who as sexton of the cemetery association is responsible for

overseeing maintenance of the Ram Pasture, said he hasn't been contacted by

Donna Ellis or anyone else connected with the biocontrol project.

"I can't imagine they'd come onto private property and let the beetles loose

without permission," he said. "We don't really know what the long-range

effects of the beetles will be. Maybe we'll want to keep the loosestrife. We

don't have any real problem in the Ram Pasture although (the loosestrife) has

gotten much thicker over the years."

It also has spread into backyards along Sugar Street (Route 302) and up Elm

Drive. Although it prefers wetlands, flood plains and waterways, it will

establish itself in open fields and may enroach on croplands, hay meadows and

forage pastures. It's not a tasty meal for grazing livestock, which generally

won't eat it.

Since the project has been publicized, Ms Ellis said she has been inundated by

requests that specific sites be selected for inclusion in the study. The

problem is that minimal funding is available so far to expand the study.

"Technicians need to go with me to the sites each year to collect data," she

said. "We want to monitor each site for five to 10 years to see whether the

beetles are able to control the loosestrife and whether the native plants

start to come back."

Ms Ellis said the states that are involved in the biocontrol experiments are

using a "national protocol" so that the same kind of data is collected and can

be compared from state to state. "We're trying to get back together as a

regional effort, although funding has not been available," she said.

Last year's survey was funded by a $5,000 grant from the US Department of

Agriculture. This year's work was funded by the UConn Cooperative Extension

Service and research grants from UConn and the Conte National Wildlife Refuge.

Ms Ellis said that because the money isn't available yet for next year, no

sites have been earmarked yet although she hopes to be able to release beetles

in at least two more locations.

"I'm very interested in hearing from regions, from municipalities, from garden

clubs - anyone who has a concern about the loosestrife," she said.