Hungry beetles wont munch on gardens, only noxious weeds

By BRENDAN MILLER on July 22, 2025.

bmiller@medicinehatnews.com

More than 2,000 flea beetles, scientifically named Aphhona lacertosa or Aphthona nigriscutis, are currently eating away on a non-invasive plant species in Police Point Park called Leafy Spurge, which has been increasing its presence and density in the park.

Leafy Spurge is considered a noxious weed that is regulated under the Alberta Weed Control Act and is the primary food source for the root-feeding fleas that measure approximately 3.5 millimetres long.

The flea beetles were captured outside Medicine Hat and provided to the city by the Alberta Invasive Species Council. They are used within Alberta, as well as Manitoba and Saskatchewan, as an alternative to chemical herbicides.

The beetles feed on the above ground plant before moving onto the soil to lay eggs in the summer. Larva will then feed on the roots of the weeds as has been proven an effective biological control agent.

Known as “host specific” the beetles will die off with the leafy spurge unless they are relocated to other areas of spurge.

Concerns from residents directed towards the city’s Parks & Recreation department around effects on gardens were addressed Monday during a public committee meeting as members heard the hungry beetles won’t target plants or flowers in garden beds and don’t like being around people.

“This isn’t going to affect your garden, they just enjoy the leafy spurge,” said Orlando Whetter, parks manager.

The beetles will almost exclusively eat the leafy spurge until it’s gone, however it may take a couple years before residents will see any noticeable effects.

“These flea beetles, once the leafy spurge is gone, will actually die off, they can only eat the leafy spurge,” said Whetter.

The city has used flea beetles, as well as goats, in previous years to help combat the invasive species. This year the city released the flea beetles into test plots of land and staff plan to document and research how effective the beetles are in reducing leafy spurge.

“We’re trying to look at ways that aren’t just chemicals,” explains Whetter, who told committee members they will be counting the numbers of noxious weeds in the fall and once again next year.

“This is kind of set up a little differently this time where we’re going to really analyze what they’re doing so that we can really see whether we’re having some serious effect,” said Whetter.

Financially, releasing flea beetles costs the city only five per cent of the cost to bring in goats twice a year to gaze on the weeds, while at the same time, providing an eco-friendly solution to invasive species.

“The goats are high maintenance, you need a lot of people around to watch them,” said Whetter who explains the city will still need to use chemicals as a supplement for the problem. “We have to look for ways that are a little more environmentally friendly.”

The flea beetles may not eat as fast as the effective grazing goats as the city expects long-term results to improve within a five-year period.

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