Tom Sweeney, Star Tribune
Pests get an early start bugging us
- Article by: JEFF STRICKLER
- Star Tribune
- April 4, 2012 - 8:55 AM
The mild winter and early spring have kicked off an atypical growing season: It's producing a bumper crop of unusual problems, including an outbreak of early-season ticks and mosquitoes and overstressed trees and gardens that could fall victim to ailments never before seen this far north.
Reports of mosquito and tick sightings are up, but we're partly responsible for that. This year's instant spring has motivated a lot of people to get outdoors ahead of schedule.
"It's not just that the bugs are out, it's that we're out, too," said Mike McLean, public information officer for the Metropolitan Mosquito Control District.
The timing can be a problem when it comes to ticks, said Jeff Hahn, an entomologist with the University of Minnesota Extension. Although black-legged ticks -- often called deer ticks and the ones that carry Lyme disease -- have been active for several weeks, he's concerned that people won't think about protecting themselves this early in the year.
"You have to do it just like you do in the summer," he said. "That's a really important message for people. You need to take proper precautions, including using a repellent containing DEET. But we're not used to doing that now."
Because winter lacked the prolonged subzero temperatures that normally kill off ticks and mosquitoes, their spring populations are booming. The mosquitoes that we're swatting now are holdovers from last summer that survived to bite again.
"We usually get a few mosquitoes that find a place to hide in the corner of a garage or something, but not as many of them as we're seeing this year," McLean said.
The mosquitoes that will torment us over the summer haven't hatched yet, although samples being collected by field agents indicate that they're probably going to arrive early, too.
"A mosquito larva goes through four stages," McLean said. "Normally at this time, we'd be seeing a lot of Stage Ones and Stage Twos; this year, we're seeing Twos and Threes."
But there's also good news on the bug front: The current projection is for a smaller-than-usual summer mosquito population because of the lack of spring runoff.
"The spring snowmelt that produces the pools that trigger mosquito breeding isn't there this year," he said. "It's still a little bit early to predict exactly what's going to happen. Our weather can change on a dime, and we still could get significant rainfall. But right now, it looks like we're going to see mosquitoes earlier but not as many of them."
We didn't get the typical snowfall or cold weather, which trees may miss the most. A severe winter is actually a boon for trees, said Kent Honl, master arborist at Rainbow Treecare. In addition to the cold killing insects and diseases, the snow provides much-needed moisture.
"I'm one of the few people who complained about this winter," he said. "We need good, old-fashioned winters."
Insects and mold spores that came through the winter unfazed already are attacking some trees. The mild winter was particularly stressful on spruces, which are battling needle loss and spider mite outbreaks, he said. And the lack of snowmelt is hampering trees' ability to fight back.
Because deciduous trees drop their leaves, they lose less moisture to evaporation over the winter. "But because they hold their needles, evergreens lose a lot of water during the winter," he said. "Without the snow, they can't replace the water loss."
To determine if your trees need watering, he suggested digging a hole about a foot deep to check the ground moisture. "You want it to have the consistency of a wrung-out sponge," he said. "If the ground is dry or powdery, the tree needs water. And the best way to do that is with a soaker hose. You don't want to use a sprinkler because that sends the water up into the air, where it gets on the foliage and can promote fungal disease."
The weather has been so abnormal that even gardening experts don't know what to expect, said Shirley Mah Kooyman, an educator and a botanist at Natural Shore Technologies.
"My gut feeling is that this is going to be a problem, but it's too early to say exactly how," she said. "We're going to have to watch our plants very carefully. I think we're going to see a slew of problems that are familiar to warmer-climate states."
The biggest danger now is a knee-jerk overreaction, she said.
"The worst thing a gardener can do is shoot from the hip," she said. "My main warning would be: Let's not all rush out to the nursery, clean off the [poison] shelves and start spraying. Let's get a handle on what's happening, first. We need to see what diseases and insects we're dealing with, then we'll be able to figure out how to treat them."
Jeff Strickler • 612-673-7392
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