Although at first glance harmless, Japanese beetles, beetles native to eastern Asia with a copper-green appearance, wreak havoc and damage to many gardens in Orléans.

This plant pest, inadvertently introduced to the United States more than a century ago, attacks a variety of plants, shrubs, trees and field crops, leaving perforated leaves in their path. Besides disfigured plants, however, these pests usually fail to destroy the plants they eat.

"None of my plants have been killed," says Carolyn Ragan, an ardent gardener who has lived in Orléans for more than 20 years.

"They lost a few nibbled leaves, but quickly replaced them," adds the passionate gardener whose Japanese beetles invade the garden annually.

"Japanese beetles are particularly attracted to plants like cannas, roses, oaks, virgin vines and more," says horticulture expert Estelle Laporte who is the owner of J.A. Laporte Flowers and Nursery. "So it's clear that (Japonese beetles) are not selective eaters."

Laporte, however, observes that the insect does not seem to be fond of certain plants such as chives, onions, leeks, geraniums and chrysanthemums.

Since chemical pesticides that limit the growth of the species were withdrawn from the market almost 10 years ago, curbing the proliferation of these beetles requires careful management, explains Laporte.

J.A. Laporte and Les Serres Robert Plante both suggest various techniques to control the proliferation of these insects.

"In our opinion, application of nematodes (microscopic worms in wettable powder form that attack larvae of plant pests) in the spring and fall, before the beetles emerge, may help prevent (the proliferation) of the Japanese beetle," suggests Laporte.

They stress, however, the importance of making sure to obtain the nematode heterorhabditis bacteriophora, the most effective product to get rid of these parasites, according to their expertise.

Among other means used to prevent the multiplication of this species, horticultural experts recommend either the use of floating canvases attached around the perimeter of the garden, the use of a shop vacuum, or the practice of throwing beetles in a soapy water solution.

Both nurseries, however, say they note a consumer preference for the use of Japanese beetle traps.

"These devices release both sex pheromones and a floral scent, a very effective strategy for attracting adult beetles," explains Laporte. "The insects fly towards the trap en masse, where they crawl or fall into the bag and cannot get out."

However, these traps have the drawback of attracting about four times as many beetles than normal. "And only 50 per cent to 75 per cent of them will end up in the bag," advise the professionals.

For Carolyn Ragan it was the starlings that came to help.

"Japanese beetles covered my raspberry tree, but a flock of starlings arrived. After these birds left, there were no more beetles in sight," she says, delighted to have been able to provide a good meal to the flock of birds.

(This story was made possible thanks to the generous support of our local business partners.)