Invasive Japanese beetle threatens P.E.I. gardens

An invasive species is spreading in Queens County and perhaps beyond, and it is causing problems for gardeners and potentially farmers.

The Japanese beetle is a big eater, and its appetite is wide-ranging. Nick Diamond of Charlottetown has found them on his nut trees.

"After picking and picking at them each day, I was able to diminish the numbers a little bit, but there are still quite a few on the trees. I think they're going to be ongoing as the season goes on," said Diamond.

"About 75 per cent of this tree is still in good shape. They might decimate 15 to 20 per cent of this tree, but I feel like without being proactive about it, they may have really taken quite a bit off the tree."

Erica MacDonald of the P.E.I. Invasive Species Council said the beetle's preferred foods include grape vines, hops, canna lily, fruit trees, roses, corn, asparagus and soybean, blueberry, blackberryand raspberry.

"You want to be monitoring constantly and monitoring early in the season," said MacDonald.

"The sooner you get out and realize you have a problem, and start to control it, the less of a population you hope that you would have."

They can be very difficult to eradicate, and it may be necessary to just get rid of the plants they like to feed on.

"If you notice you have a huge population of Japanese beetle on your property and you're growing something like roses, as pretty as those are, you may want to get rid of them," she said.

The council has had about a dozen reports of the beetle, mostly in Charlottetown and central Queens County. They are widespread in Charlottetown, MacDonald said. The first reports of the beetle were in the city in 2009.

Trying to control population

Handpicking, or collecting with a handheld vacuum cleaner for larger infestations, and then drowning them in soapy water arethe primary control methods. Neem oil can deter feeding for three or four days.

There are bucket traps that can attract and kill them, but the pheromone bait runs the risk of actually attracting more beetles to your property.

"The more people that are taking notice that the species is here and the more people that are doing something about it will certainly help us out in terms of population control," said MacDonald.

"If people aren't trying to control the problem, the problem is only going to get worse."

MacDonald hopes more people will start reporting sightings so the Invasive Species Council can get a better sense of how bad the infestation is.