23, Stouffville Sun-Tribune n www.yorkregion.com n Thursday, June 28, 2012 Weird weather signals banner year for invasive insects By Chris Traber ctraber@yrmg.com Our mild fall and winter and unseasonably warm, dry spring are a one-two punch in favour of invasive insect species, York Region natural heritage and forestry manager Ian Buchanan said. Tree-destroying critters such as the emerald ash borer and Asian long-horned beetle went into the winter in great shape, while our forests are in a weakened state, he explained. Invasive insect larvae live under tree bark. With a mild fall to enjoy prolonged feeding, the larvae were more robust heading into the winter. With virtually no winter kill, there are more of the creatures, Mr. Buchanan said. This all sets the stage for what promises to be a banner year for the emerald ash borer, which has already killed millions of ash trees in southwestern Ontario, Michigan and surrounding states. The lack of rain and early spring could have negative consequences on tree growth and ability to ward off bug infestation, he said. SUN-TRIBUNE FILE PHOTO The emerald ash borer "is the latest in a long line of threats to" trees in York Region. While the nasty invasive bugs will benefit from the dramatic weather shift, chances are traditional nuisances, including black flies and mosquitoes, could suffer. These insects and their brethren, such as the common fly, have different life cycles. Low snow cover and subsequent minimal run off and dry spells mean the moisture and standing water in which they breed is low. While the region's environmental services department doesn't monitor mosquitoes and flies, it's safe to say their populations may be diminished this year, he said. The battle is squarely against the emerald ash borer, Mr. Buchanan said. The Asian long-horned beetle is well controlled as a result of a campaign against the species, which was accidentally introduced to North America and first discovered in 1996. This beetle is believed to have spread from Asia in solid wood packaging material. The region, working in tandem with federal agencies, including the Canadian Food Inspection Agency, has likely successfully eradicated the beetle. The test of its elimination is a five year period, ending in 2013, during which hopefully none are discovered. The region has an emerald ash borer management program in place, Mr. Buchanan said. "You can't stop it, but that doesn't mean you run away," he said. "We're doing our best to control the spread." Still, it's a worry, considering approximately 10 to 15 per cent of our regional forest is ash trees. Ever the scientist, Mr. Buchanan takes the emerald ash borer in stride. "The borer is the latest in a long line of threats to the forest," he said. "There's always something around the corner. That's the natural order of things." York Region began 2012 vector-borne disease program activities in May, focusing on West Nile virus and Lyme disease surveillance, education and mosquito control. Vector-borne diseases are transmitted to humans through the bite of an infected vector organism, such as a mosquito or tick. `come and get me' Trees leafed early and are now emitting natural chemicals called volatiles that attracts pests. "It's as though the trees are calling out to the emerald ash borer and saying, `Come and get me'," he said. It'll be a challenge for the trees covering 22.5 per cent of York, Mr. Buchanan said. focus on west nile "In 2011, four mosquito pools tested positive for West Nile virus," medical officer of health Dr. Karim Kurji said. "Continued emphasis on awareness, surveillance, self-protection and larviciding activities will ensure the risk and impact to York Region residents remains low." Mosquitoes collected in Oakville and Milton in Halton Region tested positive this week for West Nile, earlier than usual, say medical authorities there. For more on vector-borne diseases, personal protection or reporting stagnant water, call York Region Health Connection at 1-800-361-5653 or visit york.ca/westnile