Olds College instructor presents eco-friendly ways to manage insects
The fire red lily beetle. The cereal leaf beetle. All types of aphids. Mosquitoes.
Many set out to annihilate these little pests and invasive species.
But there’s a greener and more eco-friendly way to manage them, notes Ken Fry, an entomology instructor in the School of Environment at Olds College.
It’s called taking biological control measures and Fry hopes to see more of it in the future.
And not just more commercial enterprises and municipalities getting on board, he said, but also everyday gardeners and family farmers.
Biological control is a pest management method that consists of introducing live organisms, whether predatory or parasitic, to interact with and reduce pest populations.
The overall goal isn’t to eliminate the pests.
“Biological control allows nature to manage itself,” said Fry.
“It’s about trying to re-establish the balance in the ecosystem after a species has been introduced to a new environment, which happens a lot through international travel, global trade, etc.”
When alien species, such as the multi-coloured Asian lady beetle (native to eastern Asia), come to North America it’s like “kids whose parents have gone away and they have the house to themselves so they can run amok,” said Fry.
They’re suddenly free from their native predators, parasitoids and diseases and all sorts of competition and pressure that kept them in check, he said.
Fry gave the example of the cereal leaf beetle, which has recently exploded in Alberta after migrating from south of the border.
This pest feasts on wheat, oat and other cereal crops, as well as various grasses.
Canadian researchers have been on the problem and have now found a parasitoid, a type of wasp, from the beetle’s native range, said Fry.
Testing is going on in the quarantine department at Agriculture Canada’s Lethbridge Research Centre.
“They expose the insect to all other types of insects in the area and see if it can survive and what else it feeds on,” said Fry.
Turns out, this wasp has a select appetite almost exclusively for cereal leaf beetles, said Fry.
There will be many more tests and consultations before the wasp is allowed to be brought into Canada.
“In the past, there was a down side to biological control, as there have been introductions into North America to control pests originally from Europe or Asia and care was not taken to ensure that their feeding preferences were narrow enough. . . . Like bringing in insects to feed on weeds and then they started eating more than weeds.”
In the last 30 years, biological control protocols have been tightened up, said Fry, who has served on the Canadian Biological Control Committee, to ensure ultimate food safety and human health.
In Red Deer, the city uses an integrated pest management, “a combination of cultural, physical/mechanical, biological and microbial/chemical pesticide control methods are used to keep environmental impacts to a minimum.”
Finding a balance between these four methods is “often a process of trial and error and this is ongoing,” said Ken Lehman, City of Red Deer’s parks, planning and ecological specialist.
The city is working to increase its physical/mechanical control efforts such as hand picking insects like the sawfly and pulling weeds, said Lehman.
But, as with any control method, there are limitations, he noted.
In terms of biological control, the city has a strong relationship with such procedures.
Thanks to a government-initiated program in the 1990s, the city placed black dot spurge beetles (Aphthona nigriscutis) in the lower Heritage Ranch area to control leafy spurge.
“Over the many years, this population of beetles has managed to survive and propagate and reduce the spurge,” said Lehman.
The city continues to monitor the beetles’ success and Lehman said they are still doing very well.
There are a number of biological control instances occurring under normal, natural conditions, noted Lehman, such as natural predators taking care of tree pests.
“Perhaps our main thrust with biological controls is to prevent disturbances of in situ natural predators. For example, reducing the use of pesticides thereby allowing them to thrive and help control pests in their natural setting.”
Another big part of the city’s integrated pest management is its nuisance mosquito control program, said Lehman.
Red Deer has been using Bacillus thuringiensis israelensis (Bti) to manage mosquitoes for the past 15 years.
This is a microbial pesticide approved for use by Health Canada.
It selectively attacks the aquatic mosquito larvae and is non toxic to other organisms in the water such as dragonfly larvae and water beetles. It also does not harm birds, mammals, fish or other animals.
“Bti is a pesticide but it’s a chemical from animal origins, naturally produced by a bacterium,” said Fry. “The great thing about it is it only kills the mosquitoes. It’s a rational tool to use.”
As biological controls increase in popularity for greenhouse owners and crop growers, Fry said it’s important to educate and train the wider public about them: “You’re not buying chemicals here; you’re buying livestock.”