Tanya Craig said the beetles are new to her garden in Prince Edward Island this year, and so far have been eating many of her plants. – Rafe Wright • The Guardian Rafe Wright, Local Journalism Initiative Reporter

Original Published on Aug 25, 2022 at 07:44

By Rafe Wright, Local Journalism Initiative Reporter

CHARLOTTETOWN, P.E.I. — Tanya Craig has been battling invasive species in her garden for over a decade.

Craig, who is the program co-ordinator for the recreation, culture and events department for the Town of Stratford, planted yellow-flag iris in her garden over 10 years ago. At the time, she was not aware it was an invasive species.

“I made the horrific mistake of planting it and I’m still battling,” Craig told the SaltWire Network during an interview on Aug. 22.

Tanya Craig from Stratford stands beneath her grapevine which has been overtaken by Japanese Beetles. – Rafe Wright • The Guardian

Several years ago, Craig bought ivy. This time she made sure to plant it in controlled spaces. Despite this, traces were soon found on the natural greenspace close to her property by the Stratford Watershed Group.

“It was only about a foot long, but even so I was mortified. I went and dug it out and disposed of it, but even now I’m really worried what can escape my garden,” she said. “I’m still pulling it out on a weekly basis.”

Tanya Craig pulls bulbs of Japanese knotweed from her garden in Stratford. – Rafe Wright • The Guardian

Increasing threat

Garden centres on the Island sometimes sell invasive flower species, either because they don’t know or they don’t take the time to do the research, said Craig.

“I was really taken aback to find out a lot of nurseries just don’t take that responsibility of selling invasive species to unknowing gardeners who haven’t done their research ahead of time,” she said.

Flowers such as lupins can be destructive to natural green spaces, so it’s important to make sure they are planted in a controlled area.

“It’s not as destructive, but you’re still spreading a plant that is not native to P.E.I. and that can be a problem,” she said.

Invasive species are becoming an increasing threat to Island green spaces.

Some of the more recent plant and bug species to the province, Japanese knotweed and the Japanese beetle, have spread across P.E.I. at alarming rates, wiping out native plant life in natural areas and home gardens alike.

About knotweed:

  • Japanese knotweed was originally imported from Japan to North America as an ornamental garden plant. Since its arrival, it has spread throughout Canada. In P.E.I. it can be spotted along trails, in gardens and along roads. Urban areas are especially prone to invasion by Japanese knotweed.
  • Japanese knotweed may be confused with giant knotweed, a relative that also grows in P.E.I.
  • Japanese knotweed is a very aggressive plant. It forms large stands which can eliminate other plants by crowding and monopolizing light.
  • It can reduce the biodiversity of an area and alter the structure of native plant communities.
  • Its vigorous shoots are known to penetrate pavement, foundations, and most anything else that blocks its path to light. It also creates problems for waterways because it can reduce the width of rivers and streams. It can also increase erosion along riverbanks because when its stems die off in the winter, there is nothing to stabilize the soil of the riparian zone.

Source: P.E.I. Invasive Species Council

The Japanese beetle was first spotted in Stratford last year, but Craig only began to see them this year.

A cluster of Japanese beetles feeding on a rose bush in Stratford. – Rafe Wright • The Guardian

“When they arrived, it was astounding. You can see them flying above my grapevine … and they are quite the dickens to kill,” she said.

Craig has stuck to using green methods, as the use of many pesticides is still banned in areas of Stratford. She also prefers using greener methods to spraying chemicals.

“I have pets and children, my grapevine is not worth the health of my family,” she said.

No. 1 killer

Japanese beetles are considered one of the most devastating invasive species in North America. They likely came to North America from Japan in 1916 during shipments of iris bulbs, according to researchers.

A side-by-side comparison of a healthy leaf as opposed to one eaten by Japanese beetles. – Rafe Wright • The Guardian

The insect was first identified on P.E.I. in 2009 on a campground between Charlottetown and Cavendish. Since then, the problem has only escalated, says the P.E.I. Invasive Species Council, with farmers now regularly observing the beetles eating their plants across the province.

Erica MacDonald, a co-ordinator with the council, told SaltWire Network on Aug. 19 that the number of reports of the beetles has increased dramatically this year, and the options for dealing with them are limited.

Few reports from the agricultural sector have been reported, with most being in urban areas.

“Once they get to a place, they are fairly hard to eradicate, and the problem only gets bigger over time.” – Erica MacDonald

The beetles are mostly attracted to roses but will eat most plant life if they do not have access to rose bushes. Some of the more at-risk plants are blueberries, peas, corn and lilies.

Erica MacDonald, member of the P.E.I. Invasive Species Council, holds up a ring of key cards identifying invasive species. The council gives the cards to residents who report an invasive species free of charge. – Rafe Wright • The Guardian

“They have a wide host range, something like a larva form will be eating grass, but the adults will pretty much eat anything,” she said.

Integrated pest management is needed for dealing with the beetles. Chemical sprays, although effective, are not recommended by the Invasive Species Council.

“It’s always going to be a battle, but more than one method should be implemented for sure,” she said.

Reports of invasive species can be made to peiinvasives@gmail.com or through the iNaturalist or EDDMapS apps.

This item reprinted with permission from The Guardian, Charlottetown, Prince Edward Island