Preventing Pesky Garden Pests

Shawna O'Neill, TC Media
Preventing Pesky Garden Pests
Joe McNamara shows off his fat bike at the entrance to the Summerstown Trails on their opening day on Sunday

CORNWALL, Ontario – Japanese Beetles, Scarlet Lily Beetles and Emerald Ash Borers are a few common pests that might be tormenting your garden this summer. Gardening enthusiasts have developed preventative measures against the insects, but some are more effective than others. 

“The main pest everyone is trying to deal with is the Japanese Beetle,” said Sandra Mitchell, President of Cornwall and District Horticultural Society. “This little devil has a metallic green back, and has two purposes in life: to reproduce, and to eat almost every plant he can. The only plant that it will definitely not eat is geraniums, because they are poisonous to them.”

“Due to the pesticide ban in Ontario, the City can not spray for the beetle. The beetle is a nuisance and does eat the leaves of plants but is not classed as a pest that can be sprayed,” said Scott Porter, Parks and Landscaping Supervisor with The City of Cornwall. “The City does not do anything about the beetles. Residents can buy the pheromone traps but unless the neighbours around the area are also trapping, putting traps in your yard will (attract) the beetles to your yard and increase the population around your plants.”

Alternatively, Mitchell suggests spraying yards with beneficial nematodes in the spring or fall, which will release bacteria into the white grubs that become Japanese Beetles. This will help to reduce the number of host grubs, and consequently reduce the population. Another suggestion of Mitchell’s is to hand pick the bugs and place them in a jar with soapy water to exterminate them. She has heard that the beetles will send a distress signal to other beetles if they are squashed.

When it comes to tackling Emerald Ash Borers, Mitchell thinks it’s best to get rid of the infected tree entirely. Once the tree is cut, it must be ground up in the area it’s found in to prevent spreading.

“If you have an Ash tree infected with this bug, then in my opinion, you should just have a professional come in and cut it down,” said Mitchell. “The treatment for the tree infected with this bug is extremely expensive, must be done by an expert and at most will only prolong the tree’s life, not save it.”

“The city continues to monitor the infestation of Ash Borer in the City,” said Porter. “Parks and Landscaping is in the process of injecting over 400 trees with TreeAzin to protect the trees from the insect. The city continues to remove dead or dying City ash trees and replacement of a tree once the Ash is removed.”

According to Mitchell, the Scarlet Lily Beetle can decimate an oriental or Asiatic type of lily in just a year. The beetle will eat its way through the lily, from bottom to top, and will defecate on the plant, which is often mistaken as ground.

“Some have found success using horticultural oil and saturating the top inch of soil where your lilies are coming up,” said Mitchell. “This stops the beetle from emerging. Others have found removing that inch of soil from your lilies gets rid of the larva of the beetle. Of course you can also use the (soap water) jar and hand pick the red devils!”

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