Weevils vs. The Mile-A-Minute Weed

  • The mile-a-minute weed (Photo courtesy of the USDA)

Sometimes biologists fight foreign
pests with other foreign animals. But that
can be risky because it can create a bigger
problem than the one it’s supposed to solve.
Sabri Ben-Achour reports on one of the latest attempts to stop a weedy pest:

Transcript

Sometimes biologists fight foreign
pests with other foreign animals. But that
can be risky because it can create a bigger
problem than the one it’s supposed to solve.
Sabri Ben-Achour reports on one of the latest attempts to stop
a weedy pest:

On farms, backyards, and rights of way up the Eastern Seaboard a pointy leaved thorny
newcomer is becoming increasingly visible. It’s called mile-a-minute weed.

Bob Trumbule is an entomologist. He leads me through a stream valley north of
Washington DC where blackberries and small trees are being swallowed up by this
invasive vine.

“So now we’re getting into the mile-a-minute here. Basically what it does it, it’s an
annual vine, it grows up and over plants, it smothers them, out competes them for
sunlight, and weighs them down.”

The weed is native to Eastern Asia: China and Japan. It was introduced accidentally in
Pennsylvania in the thirties. From there, it’s spread to seven other states. It prevents new
trees from sprouting in forests. But back in Asia, it’s not a dominating species like it is
here.

Judith Hough-Goldstein is a professor at the University of Delaware.

“Part of the reason is because it doesn’t have anything that’s feeding on it. It’s gonna be
without its predators so it can out-compete other plants.”

Over several years, biologists searched for something that would eat the vine. They
found a tiny, black weevil in China. It feeds on the plant and lays it’s eggs there, keeping
things in check – in Asia.

“Here are the weevils. I’m gonna give you a glimpse of them here in the cup. They look
almost like little ticks. I’m gonna put them down here in the mile a minute weed patch,
and basically what they’ll do – they’re tough little guys – they’ll climb around and in the
past experience have started to feed almost immediately.”

Up close, they look like little anteaters, poking around the leaves with long snouts.

This may sound risky. There are lots of examples where similar approaches have gone
wrong. A parasite was introduced in North America to control gypsymoths. It attacked
native silkmoths. Mississippi catfish farmers used Asian carp to control algae. They got
loose and are taking over the Mississippi River system and threatening the Great Lakes.

And Trumbule admits nobody knows for sure exactly what might happen.

“Any scientist that might say otherwise is not being honest with themselves or the person
asking the question.”

But he says a lot’s been learned since the days when any scientist could introduce a
species on a whim. These days, exhaustive testing and federal permits are required
before anything is released.

That’s why for almost ten years Judith Hough-Goldstein has been trying to determine if
the weevil would eat anything else. Tests were conducted in a U.S. Department of
Agriculture ‘quarantine facility’ with sealed windows and its own re-circulated air supply.

“So what we found was that, in fact, this particular weevil is extremely host specific. The
insect has evolved to depend on the plant.”

So much so that the weevils and larvae actually starved to death rather than feed on other
plants.

In field tests in New Jersey and Delaware, the weevils have decimated mile-a-minute
weed. Some researchers say it’s the most impressive biocontrol they’ve worked with.

For The Environment Report, I’m Sabri Ben-Achour.

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Paying for Peak Power

  • Advanced, individual meters that calibrate energy prices for each apartment. (Photo by Samara Freemark)

Energy prices are rising, and people are looking
for ways to conserve power. But some rate payers are
saving money without actually cutting their energy use.
Instead they’re changing when they use power. Samara
Freemark reports:

Transcript

Energy prices are rising, and people are looking
for ways to conserve power. But some rate payers are
saving money without actually cutting their energy use.
Instead they’re changing when they use power. Samara
Freemark reports:

It’s Saturday morning, and Ellen and Peter Funk are doing laundry.

The Funks used to do chores when most people do – they would get home from work and
switch on their dishwasher, dryer, and computer. They never really paid attention to
what that meant for their electricity bill.

“I never thought about electricity before. Never, never, never. Except when I got the bill.
But, you didn’t have any control. Because you paid the same price whether you used it at 2 in
the morning or 2 in the afternoon.”

But a couple of years ago the Funks started paying for their electricity differently than the
rest of us. They live in one of only a handful of buildings in New York City that
participate in a Real Time Pricing program.

Real Time Pricing charges consumers a different rate depending on when they use power.

The Funks know that running their dishwasher or turning on a light will cost more at 5
pm than at 10 pm. That’s because they get a color-coded chart every month that breaks
down their energy prices by time block.

“The green here is low. And the green starts at 10 o’clock at night and goes through 1
o’clock the following afternoon. The yellow is medium from 2 to 5 every day. And then
Monday to Friday there’s a high period from 5 to 9. That means stop. I think that’s why
they used red.”

It’s the same concept that makes cell phone minutes cost more during the day. Power
costs more when more people want to use it.

Real Time Pricing can save consumers a lot of money. Peter Funk says his family saves
hundreds of dollars a year by just shifting when they use energy.

“It’s an ongoing savings. We do these things because they make sense economically. We
don’t do it because we’re virtuous, we don’t do it because we’re better than our neighbor.
We just, this is the way we buy electricity because it makes sense.”

Real Time Pricing programs shift around power demand, so fewer people use energy
during peak hours. A Department of Energy study earlier this year estimated that Real
Time Pricing programs could cut peak energy use by about 15%.

That could actually help regions improve air quality and conserve resources by
decommissioning old, polluting power plants. Here’s how.

Most areas have a network of power plants. Usually only a few of those plants – the
newest, cleanest ones – are in use. But when energy demand peaks, the older, less
efficient plants kick in. And those plants spew a lot of carbon dioxide and other
pollutants into the air.

“It’s really not the number of power of power plants, but the ones you have to turn on at
critical times.”

Jim Genarro is a New York City councilman. He also chairs the council’s Committee on
Environmental Protection.

He says the plants that kick in when demand peaks are the worst in the system.

“We have a lot of reserve capacity in the city, but these are the older, dirtier plants, and
when you run those at peak capacity, it really means a lot of pollution.”

And Genarro says those plants cost even when they’re not producing energy. The city
has to maintain them all the time so they can switch on when needed. That wastes energy
and resources. It also means there are power plants that are only used a few weeks, or
even days, a year.

If power companies could cut peak energy demand, rarely-used, polluting plants could
become totally unnecessary. And many could be shut down.

For The Environment Report, I’m Samara Freemark.

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