[APWG] FW: Mile-A-Minute, Polygonum perfoliatum

Tue Jul 17 12:03:20 CDT 2007

We always treat the other non-native invasive plants that might otherwise
move in. Marc

  _____  

From: Bob Beyfuss [mailto:rlb14 at cornell.edu] 
Sent: Tuesday, July 17, 2007 11:45 AM
To: Marc Imlay
Cc: apwg at lists.plantconservation.org
Subject: Re: [APWG] FW: Mile-A-Minute, Polygonum perfoliatum

Hi All
I am not familiar with the mile a minute vine eating weevil but here in NY a
colleague of mine at Cornell University, Bernd Blossy in conjunction with
our conservation department released purple loosestrife eating beetles as
long as 16 years ago. I considered this bio control program a failure until
this year. I am not sure why, but this year the purple loosestrife is 99%
gone from literally thousands of acres of wetlands, roadsides and virtually
everywhere it had become established within my county. It may take many
years for such releases to work but this year the effect is almost
astonishing. 
I also am pleased to read that some people realize that broad spectrum
herbicide applications to eradicate invasive plants may do far more harm
than good by creating biological vacuums which will soon be quickly
colonized by other invasive plants while inadvertently killing some of the
plants one wants to preserve in the first place.  I think resource managers
need to focus more on what is the desired outcome of any actions they take
before they take them. Simply killing invasive plants for the sake of
killing them (gratification?) is not necessarily, in my opinion, a desired
outcome unless one can accurately predict what will replace them when they
are gone. Assuming desirable native plants will automatically become
reestablished once the exotic invaders are killed is a naive assumption.
Think before you spray!
Bob

 At 09:25 AM 7/17/2007, you wrote:

  _____  

From: Hough-Goldstein, Judith [ mailto:jhough at udel.edu
<mailto:jhough at udel.edu> ] 
Sent: Monday, July 16, 2007 9:10 AM
To: ialm at erols.com
Cc: ma-eppc at yahoogroups.com; rreardon at fs.fed.us; elake at udel.edu
Subject: Mle-a-minute biological control

Mark,

With respect to your comment "Bio-control is having mixed success according
to reports", I just want to remind everyone that this is only the third year
the mile-a-minute weevils from China have been in the field, and in fact the
majority of the releases so far were done in 2006, with a few in 2005 and
very few in 2004. Most consisted of relatively few insects. It is normal for
it to take some time before anything definitive can be said about the
effectiveness of an agent - at least 3 years, and sometimes up to 10 years.
The insects take time to build up in numbers, and in some cases they also
need time to adapt to regional conditions. So far we know that the weevils
can establish in a variety of habitats, produce multiple generations during
the season, and disperse readily to new patches. As to impact on the plant
populations, time will tell.

Judy Hough-Goldstein
_______________________________
Judy Hough-Goldstein, Professor
Dept. Entomology & Wildlife Ecology
531 South College Ave.
University of Delaware, Newark DE 19716-2160
http://ag.udel.edu/enwc/research/biocontrol/index.htm

  _____  

From: Marc Imlay [ mailto:ialm at erols.com <mailto:ialm at erols.com> ] 
Sent: Tuesday, June 26, 2007 9:34 PM
To: 'Aliens-L at indaba.iucn.org'
Subject: Mile-A-Minute, Polygonum perfoliatum

Three of us used garden rakes followed by hand pulling in Little Paint 
Branch Park, Beltsville MD on June 22, 2007 and removed 20% of 
the massive 25 by 100 patch of Mile-Minute in an open area 
in 2 hours. For example, the three volunteers in 15 minutes used 
the rakes very gently to remove about 80% of the Mile-a-Minute 
in a 20 x 20 patch about 50% invasive vine cover over 50% native 
cover including sensitive fern, asters, sycamore and sweet gum 
seedlings and Virginia creeper. The herbaceous natives were not 
damaged and it was then easy enough to hand pull the remainder in 
30 minutes. When we tried to pull very hard at another spot, native 
plants, including a virgin creeper, were damaged. Hand pulling alone 
would have been seen as hopeless and herbicides would have 
damaged the natives. Bio-control is having mixed success according 
to reports. Cheers.

Marc Imlay
Laura Malick
Mike Breen 

Marc Imlay, PhD

Conservation biologist, Anacostia Watershed Society
(301-699-6204, 301-283-0808 301-442-5657 cell)
Board member of the Mid-Atlantic Exotic Pest Plant Council,
Hui o Laka at Kokee State Park, Hawaii
Vice president of the Maryland Native Plant Society,
Chair of the Biodiversity and Habitat Stewardship Committee
for the Maryland Chapter of the Sierra Club

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