The Reminder is making its archives back to 2003 available on our website. Please note that, due to technical limitations, archive articles are presented without the usual formatting.
Manitoba Conservation has been fielding calls from residents anxious to rid their yards of hungry green worms dining on tree leaves. Often seen dangling from trees by a silk thread, worms known as boxelder leafrollers have been plaguing trees across the community. "They just eat all the leaves on your trees. There's no leaves left, and it just looks awful," said one uptown resident with hundreds of the pests in her back yard. "You can't even go outside and enjoy your yard because they're just all over. They're like Spider-Man with all these webs." Another resident recalled seeing the worms in previous years but never to the extent they are out this summer. A number of yards around the community have become infested with the worms, which Conservation says tend to target Manitoba maples, though they may also go after shrubs and other types of trees. The nuisance has meant big business for retailers who carry pesticide. Canadian Tire, for instance, sold out of the popular spray Malathion. Some residents are concerned the worms may destroy their trees, but Keith Knowles, a forest health biologist with Conservation's Forestry Branch in Winnipeg, said there's likely no reason to worry. "They won't kill your tree," he said. "If it's a well established tree, it can certainly handle the defoliation. It would probably only become a real concern if the trees were stripped three or more consecutive years." Knowles feels it's getting too late in the season to bother spraying the pests, as the damage is likely done. "There's only one generation a year, so the next set of leaves aren't going to be fed upon," he said. Once a host tree is defoliated, boxelder leafrollers generally inch their way to the ground on a silk thread so they may "pupate," a 10-14 day process in which they transform from larva into moths. If the tree is not defoliated, the worms tend to seek out a leaf in which to wrap themselves and pupate. Spruce Budworms, which feed primarily on white spruce and balsam fir, and occasionally black spruce, have also been common this summer. Conservation recently sprayed forestry blocks in the area for the worms, but was not permitted to treat residential areas. In dealing with both worm species, Conservation recommends people use a pesticide containing "Bt," a spore-forming bacterium. Specific questions about worms may be directed to Conservation at 1-866-626-4862.
