Effingham Daily News, Effingham, IL

Features

March 3, 2014

Polar vortex may prove to be a powerful pesticide

— This winter is a real killer.

The deep freeze, with arctic blasts from the polar vortex, has put invasive insects on ice in dozens of states. That includes the emerald ash borer, a pretty bug that does ugly things to ecosystems it invades.

Up to 80 percent of the ash borers died when January temperatures dipped below minus 20 degrees Fahrenheit in St. Paul, Minn., according to an estimate by U.S. Forest Service biologists, who have been conducting studies on the impact of cold weather on the bugs for the past three years.

Their estimates were affirmed when state researchers found that nearly 70 percent of ash borers collected from infected trees in the Twin Cities area last month were frozen stiff - a good thing for ash trees that adorn communities and provide smooth, durable wood used for flooring, bowling alleys, church pews, baseball bats and electric guitars.

Across the country, other destructive pests are dropping dead, including the hemlock woolly adelgid, which preys on Christmas trees in the Appalachian Mountains; the kernel-munching corn earworm, found in nearly every state; the citrus-destroying cottony cushion scale that migrated to Maryland from Florida; and the gypsy moth, which chomps on 80 species of trees and is spreading from the Northeast to the Midwest.

The bugs found their way to the United States from all over the world and thrived in the relatively warm winters of recent years. At least two of the pests mounted great migrations from the Deep South to Virginia and Maryland.

For now, at least, the freeze has stopped them in their tracks. Researchers in the Appalachians of West Virginia and Maryland found hemlock adelgids whose little, straw-like mouths were stuck to the pine needles from which they suck nectar.

"If you poke them with a stick, they'll normally move their little microscopic legs," said Patrick Tobin, a research entomologist for the Forest Service in Morgantown, W.Va. But not this winter.

Based on surveillance, researchers believe more than 95 percent of hemlock adelgids were killed in the northern Appalachians and at least 70 percent died in their southernmost range, Georgia.

At first blush, this appears to be great news, Tobin said. Important trees, including ash, birch and oak, and such vital crops as soybeans, corn and oranges will probably get a break from millions of gnawing mouths.

But invasive bugs are a breed apart. Built to last, they almost never experience extinction.

Female adelgids and cottony cushion scales, for example, are asexual creatures that produce nymphs without copulation. Three generations or more will spring to life between March and October.

As for emerald ash borers, that Minnesota deep freeze affected only a limited number. Chicago also has ash borers, but temperatures there fell only to 17 degrees below zero and likely didn't faze the insects. Minus 20 is the point at which they start to die.

"This problem is not going away," said Rob Venette, a Forest Service research biologist who studied the ash borer.

Winter's blow to the pests is more like a reprieve, said Mike Raupp, a professor of entomology at the University of Maryland, "a little correction" that thinned their ranks and probably will slow them down when warm weather returns.

The cold weather provided a stage for a grand experiment that will help researchers determine if significant numbers of pests can be killed off, making the problems they create more manageable, Raupp said. A decade of study is needed for any definitive conclusions.

Raupp studies the crop-eating brown marmorated stink bug. He said he'd like to be "cautiously optimistic" that winter wiped out huge numbers of them in the mid-Atlantic states, where they have feasted on farm crops for years.

 An experiment conducted by an entomology professor at Virginia Tech gave him hope. Stink bugs placed in foam insulated buckets had a 95 percent death rate when temperatures hovering around zero persisted for days.

The bucket simulated overwintering hideouts in Blacksburg used by stink bugs to protect themselves from the cold.

The conclusion? "There should be significant mortality of [stink bugs] and many other overwinter insects this year," the professor, Thomas Kuhar, told The Washington Post Capital Weather Gang last month.

But Raupp, who called Kuhar "a top-notch researcher," is more guarded. Blacksburg had a few days at 4 degrees below zero, but Maryland did not.

A research entomologist for the Agriculture Department also has low expectations. When researchers for the USDA visited outdoor sites in Maryland where stink bugs spend the winter, they found the same mortality rate - about 50 percent - as in earlier winters.

"Unfortunately, they're doing just fine," said the entomologist, Tracey Leskey.

Stink bugs are from China, where temperatures often plummet. Even if they did die in bunches, they enter "winter with an enormous population," so plenty of survivors rush out in spring to multiply.

A large group of stink bugs cozied up in the warm homes of residents who couldn't seal enough cracks to prevent them from slipping through.

"Every day, I've had a stink bug wandering across my desk," Raupp said. "They're doing fine in my house."

It might seem that frequent snowfall would help kill the bugs, entomologists said, but instead it insulates and protects them.

As if stink bugs weren't bad enough, another invasive bug from Asia has made its way to Maryland. Detected in Georgia in 2009, the soybean-loving kudzu bug has since decamped toward the north.

This winter's polar shock might be that insect's Waterloo. University of Georgia entomologist Wayne Gardner said kudzu bugs are slowed by just a layer of frost. Maryland's temperatures dipped to 5 degrees.

The corn earworm that devastates that crop prefers tropical climates, and typically heads south when temperatures cool. The vortex that hit 49 states with extreme cold and snow offered few safe havens. And gypsy moths were found frozen and flat on their backs near trees they infect.

But the cruel winter apparently had little effect on ticks. In New Hampshire, they continue to weaken adult moose and kill calves. Tick populations are booming because cold weather now arrives in mid-October, too late to kill them in the brush where they wait to hitch a ride on moose until May.

"We've had a higher tick load on moose this fall than we've ever seen, except for one year previously," Kristine Rines, a wildlife biologist and moose project leader for New Hampshire's Fish and Game Department.

To disrupt the tick reproduction cycle, winter would have to arrive "at its regularly scheduled time" in New Hampshire, around late September, said Rines. "We've already seen some . . . calves dying."

 

1
Text Only
Features
  • Study: Kids gain weight more quickly over summer break

    Any parent or teacher can tell you that schoolchildren tend to slip back a bit academically over the long summer break. But now a Harvard University study has come up with troubling indications that they also gain weight more quickly during those months when, traditionally, we hope they're outdoors much of the time, enjoying the summer sun.

    June 16, 2014

  • 20140614-AMX-RETIRE-GENX14.jpg Lean retirement looms for Generation X

    When their working years end, Gen-Xers might have to live on just half of their pre-retirement income, compared with 60 percent for the Baby Boom generation, Pew said last year.

    June 16, 2014 1 Photo

  • 20140612-AMX-FATHERS-CARDS123.jpg Father's Day cards make subjects the targets of jokes

    There's a good chance if you receive — or give — a Father's Day card this weekend, Dad will be portrayed as a flatulent, beer-obsessed, tool-challenged buffoon who would rather hog the remote, go fishing or play golf than be with the kids.

    June 15, 2014 3 Photos

  • Texting while driving is latest teen risk as smoking declines

    While smoking among American teens has fallen to a 22-year low, most adolescents admit to engaging in a new type of risky behavior: texting while driving.

    June 15, 2014

  • $15 minimum wage puts Seattle in uncharted waters

    Depending on which pundit is nattering away, this means Seattle is either going to fall off the map and become a "Mad Max"-style economic wasteland or transform into an egalitarian utopia that inspires sweeping pro-labor activism nationwide.

    June 7, 2014

  • 2010-Winter-Olympic-Games-001.jpg Nobody wants to host the Winter Olympics

    If we end up watching slopestyle from the Central Asia steppes in 2022, it will likely be because it's becoming clear that nobody in Europe wants to host these Olympics anymore. Publics may finally be getting wise to the fact that the long-term economic benefits of hosting mega-events like the Olympics or the World Cup are usually negligible at best.

    May 27, 2014 1 Photo

  • airplanes-work-1.jpg Airfare honesty? It may be an oxymoron

    The issue of fare advertising has taken on a renewed sense of urgency now that Congress is considering removing the Transportation Department's full-fare advertising rule, which requires airlines and ticket sellers to display a price that you can actually book.

    May 27, 2014 1 Photo

  • Study: Both men and women feel less stress at work than at home

    In a newly released study in the Journal of Science and Medicine, researchers carefully examined the levels of the stress hormone, cortisol, of a variety of workers throughout the day. The data clearly showed that both men and women are significantly less stressed out at work than they are at home.
     And the women they studied said they were happier at work. While the men said they felt happier at home.

    May 27, 2014

  • Five myths about caffeine

    But how much do you know about the drug - and yes, it is a drug - you're consuming? Before downing one more gulp of your favorite stimulant, let go of some persistent, caffeinated myths.

    May 27, 2014

  • Making the most of longer school days

    Research shows that extra time doesn't help unless it is well used. With that in mind, the Boston-based National Center on Time and Learning has just released recommendations on the best way to construct a longer school day.

    May 26, 2014

AP Video
Parade
Magazine

Click HERE to read all your Parade favorites including Hollywood Wire, Celebrity interviews and photo galleries, Food recipes and cooking tips, Games and lots more.