The exterminator

Photo courtesy D. Sikes/Flickr

For almost 30 years, Shawn Meckelborg has been battling blackflies in local river systems to protect the region’s livestock

He’s back, and if you’re a blackfly, he’s public enemy number one.

Every spring and summer for almost 30 years, Shawn Meckelborg has patrolled local river systems with a non-chemical insecticide to kill the larvae of those pesky bloodsuckers.

The spraying program is funded by the Ministry of Agriculture with a grant, and is run by the District 32 Agriculture Development and Diversification Board, which includes members from each of the rural municipalities in the abatement area. The program uses a bacterial pesticide called BTI, or Bacillus thuringiensis subspecies israelenis. According to the United States Environmental Protection Agency (EPA), BTI is a biological or naturally occurring bacterium found in soils. It contains spores that produce toxins that specifically target the larvae of mosquitos, blackflies and fungus gnats.

“It’s not a chemical and it’s non-toxic,” Meckelborg said.

“It’s very target-specific and very effective. It will kill the larvae, and you don’t get the non-target ones, the ones that are helping you. It’s very environmentally friendly and specific that way.”

Meckelborg said he doesn’t have to wear special gear to handle BTI and the containers are recyclable, going right in with food grade containers.

While the spraying has the added benefit of making life more tolerable for humans, it’s actually done to prevent losses to livestock. According to Meckelborg, a 1975 study estimated the cost of black flies in the livestock industry at $3 million annually. That’s the equivalent of $14.2 million today.

While blackflies won’t directly kill an animal, they can cause them to stampede, or to stop feeding. They’ll also target soft tissue, preventing calves from suckling. In rare cases, they’ll swarm a cow’s throat and suffocate them.

“They do cause quite a bit of damage in different ways.”

To combat those losses, spraying starts in the spring and continues into the fall. The insecticide is applied to moving bodies of water, where the blackfly larvae thrive.

“They’re in the water,” Meckelborg explained.

“They have no means of motility and need food to come to them. That’s why they’re in flowing water. They have filaments almost like tentacles that grab food as it comes by to feed. What I send out is a bacterium they feed on. That bacteria kills the gut pH, killing the larvae that way.”

Treatments are done to the North and South Saskatchewan River, as well as the Saskatchewan River east of the forks. It is also done on the Torch, Garden and Little Red Rivers, as well as Bedard and Miners Creeks.

“We spray from … the beginning of our abatement zone and spray all through the river system,” Meckelborg said.

“It’s mostly done in the spring and we run it through the summer. But we target the spring populations because that gives you the best bang for your buck. If you knock those down, because females can lay thousands of eggs, if you get that first population off you’ll see fewer flies throughout the year.”

How often the treatment is applied depends a lot on the river. It depends on flow rates, as the insecticide has to reach a certain concentration. If water levels are high, more pesticide has to be used, which means more money, more budget spend and fewer treatments later on in the year.

The current iteration of the program has been in place since 1990. So far, Meckelborg said, it has proven very successful.

“Sometimes I think we’re a victim of our own success,” he said.

“People don’t realize we’re still out here doing it. It’s been almost 30 years for myself. You’re going to have good and bad years. It’s the environment, rather than the program changing. It’s been good so far, good this year anyway.”