Tag: biological control

Wasp Kills Pines

  • The Sirex woodwasp is killing pinetrees in New York, Pennsylvania and parts of Ontario and seems to be spreading. (Photo by Lester Graham)

Foresters are worried about a wasp that’s killing pine trees. The insect is
spreading through pine forests in northern states. Steve Carmody reports:

Transcript

Foresters are worried about a wasp that’s killing pine trees. The insect is
spreading through pine forests in northern states. Steve Carmody reports:


The female Sirex woodwasp injects a combination of a toxic mucus and a
fungus while laying her eggs in pine trees. The mixture feeds the eggs, but
kills tree cells, often further weakening stressed pines.


In the three years since it first appeared in upstate New York, the Sirex
woodwasp has spread to 25 New York counties, and two counties in
Pennsylvania and part of Ontario.


Bob Heyd, with the Michigan Department of Natural Resources, says the Sirex
woodwasp is spreading:


“The wasp is actually very strong fliers. They can fly 70 or 100 miles, so what it
is here… it will disperse very quickly.”


In other countries, forestry officials have found an imported predatory
nematode from the wasp’s home range in Europe has been an effective
biological control. It’s unclear if officials in the US will try the same
tactic.


For the Environment Report, I’m Steve Carmody.

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Summer Battle Plans for Aquatic Plant

Now that spring is here, aquatic plants are beginning to flourish. The Great Lakes Radio Consortium’s Ashley McGovern has an update on the battle against the Eurasian watermilfoil:

Transcript

Now that spring is here, aquatic plants are beginning to flourish. The
Great Lakes Radio Consortium’s Ashley McGovern has an update on the battle against the
Eurasian watermilfoil:


The Eurasian watermilfoil originated in Europe and Asia and has been found in the US for more
than 80 years. Watermilfoil can be transferred from lake to lake by boaters. The plant can hinder
recreational activities, like swimming and fishing, and can harm native ecosystems.


Lake associations and ecologists are trying to find ways to stop the spread of this invasive plant.
Bernd Blossey is an ecologist with Cornell University. He says people use different tactics to try to
get rid of watermilfoil.


“Some people promote using aquatic herbicides but that’s never a long-term solution—the plant
simply comes back.”


Another technique used is called biological control. That’s introducing natural enemies, such as
insects, that feed on the plant.


“Biological control doesn’t try to eradicate a plant, it just tries to reduce it’s population level.”


Blossey says it’s important to increase awareness of invasive species like watermilfoil and to keep
in mind that using herbicides is just a temporary solution to a tough problem.


For the Great Lakes Radio Consortium, I’m Ashley McGovern.

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Invasives Leave Parasites Behind

Plants and animals that come from overseas sometimes out-compete species that are native to the region. Scientists have long debated what makes the invaders so successful. One hypothesis is that invasive species have fewer natural enemies. New research supports this idea. The Great Lakes Radio Consortium’s Rebecca Williams has details:

Transcript

Plants and animals that come from overseas sometimes out-compete species that are native to the
region. Scientists have long debated what makes the invaders so successful. One hypothesis is
that invasive species have fewer natural enemies. New research supports this idea. The Great
Lakes Radio Consortium’s Rebecca Williams has details:


Invasive animals and plants have fewer parasites and diseases than their native competitors.


That’s according to two new studies published in the journal Nature. In one study, researchers
analyzed parasites of 26 invasive species, including the zebra mussel.


Kevin Lafferty is an author of the study. He says when a foreign species invades a new area, it
leaves most of its parasites behind. He says importing those natural enemies might be a good
way to control invasives.


“There’s still several species, on average, about 13 parasite species back in the introduced
species’ home range, that we could consider for biological control, and of course an important
part of that process is to determine which ones might be safe, in terms of not infecting our native
species.”


A second study looked at nearly 500 plants that have been brought into the U.S. Researchers
found that plants that leave behind the most pathogens are the most likely to become invasive.


For the Great Lakes Radio Consortium, I’m Rebecca Williams.

Controlling the Lamprey

The assault against sea lampreys in the Great Lakes continues, as biologists from the U.S. Fish and Wildlife Service are combing the waters of West Michigan’s Lincoln and Pere Marquette rivers this week. The Great Lakes Radio Consortium’s Matt Shafer Powell has more on the government’s on-going attempts to keep this creature under control:

Biological Control Gone Awry

Many of the earth-friendly pest control methods developed by organic farmers have become popular among gardeners and homeowners. But when Great Lakes Radio Consortium commentator Tom Springer bought guinea hens to eat troublesome insects, he ended up with a different kind of pest… and a new respect for the challenges of organic agriculture: