Bringing down the budworm
By Katie Lewis

OTTAWA — Every few decades, the eastern spruce budworm, choristoneura fumiferana, ravages forests throughout Canada and the United States. One local scientist has had enough – and he's using an age-old idea to banish the budworm.

He's using nature to fight nature.

The little worm that could

Choristoneura fumiferana, or eastern spruce budworm.

The budworm has a long history in Canada – with natural cycles occuring every thirty years or so over the last couple of centuries. It has gradually developed a resistance to chemical pesticides.

Dr. David Miller, a Carleton University Researcher in Biochemistry, is looking for an alternative way to banish the budworm. He says his research has shown him that an enemy of the budworm is a family of needle-loving fungi.

Dr. Miller says the idea of using fungi against the budworm occurred when he went to a Colorado conference and a colleague wondered aloud if it was possible that endophytes – which are fungi living inside conifer needles – may produce toxins which work against the budworm.

"Science, like everything else in life, works on some kind of trade basis," says Miller. "They traded me something, which was an idea, and the return they got was somebody who actually knew how to figure out if this was true.

Looking for evidence

For the past 20 years, Miller has worked on uncovering the answer . Through his research, he found 90 to 95 per cent of the endophytes living in the spruce trees did not produce toxins, but that 5 to 10 per cent produced toxins that worked against the budworm

Dr. David Miller, Carleton University.

Older trees which had survived budworm outbreaks had larger amounts of these toxins. The endophytes which didn’t produce toxins were known as "cheaters."

Miller says, although the idea sounds simple, it was incredibly risky at the time. He says he was pleased with the way the grant system in Canada worked, considering the difficult research he was undertaking.

" It’s like looking for a needle in a haystack and you don’t know what the needle looks like," says Miller. "It was that hard. It was so risky in the probability of success."

Convincing the company

Miller’s next step was to convince a forest company to help him with his research. He was looking for seedlings to experiment with.

"We needed a breeding population of white spruce trees, about 6000 of them, and there’s only one organization on the planet that has them. It took a while to convince them to give those up."

Miller did end up convincing forestry company J.D. Irving Limited to supply the trees after his research was peer reviewed and the science was found to be sound.

He was asking J.D. Irving Limited to give up a large portion of their best and rare conifers through a tree improvement program. However, if the research worked, the company would be rewarded with an ability to have well-protected seedlings forever.

White spruce tree greenhouse.

"In terms of the breeding population, the way you’d need to think about it, is if you have 13 kids and I needed to kill one of them you’d still have 12, but it’s not like it’s a small thing. It was a big thing"

Miller experimented using several different methods of injection as a way to introduce "good" endophyte cells into the seedlings. At the end of this part of the project, 200 seedlings from a total of 6000 showed that they had been colonized. The "good" endophyte inoculations were successful.

Although the number was low, Miller says it was an important stepping stone. First, he realized it could be done. Second, he found out what types of injection worked best.

Educated at the University of New Brunswick as well as the University of Portsmouth in England where he was a NATO science postdoctoral fellow, Miller is now part of the Chemistry faculty at Carleton and is the the NSERC Industrial Research Chair Fungal Toxins and Allergens. He’s worked at Agriculture Canada, and is currently a visiting scientist with Health.

The next step

The collection of white spruce trees.

Miller says his journey to get rid of the budworm is not over yet. He’s been working on the project since he was 28, and says he hopes that the end is in sight in about three years. At this point, the company could start doing injections on the majority of its spruce trees.

However, he’s tentative to formally pin down a date, as new things might come up, and new discoveries could be made. He says the biggest virtue of any scientist is patience.

"It’s a very long journey," says Miller. "That’s relatively typical in science. You have to be patient and have a long view of things."