Shoo fly, don’t bother me!

The Van Winden family leaned into the light to stop a pesky pest on their multi- generational family farm

Agricultural production often requires excellent problem-solving skills. The owners and workers at Delfland in Napierville, Quebec, know it well. And when they faced the problem of a devastating insect pest threatening a valuable crop, they turned to a group of researchers to bring their innovative thinking together and find a solution.

Beyond the family farm

Delfland, a family farm, has been at the forefront of agricultural innovation for many years now: since 1984, they have been a member of the PRISME Consortium, an association of vegetable producers and professionals involved in research, development and implementation of Good Agricultural Practices (GAP).

Yvon Van Winden, co-owner of the farm with other family members, acts as a farming coach and is responsible for collaborating with the PRISME Consortium. “Each farm works with PRISME to find solutions to its specific problems,” Yvon explains.

A crop at risk and a potential solution on hand

In the past, the owners of Delfland worked with the PRISME Consortium to successfully protect their onion crops from a pest using sterile flies. This pest management tactic, observed by the Consortium during a visit to Holland, in the Netherlands, involves subjecting the flies to targeted light and radiation treatment to sterilize them. The sterile male flies are then marked and released into the fields. When they reproduce with fertile female flies, their larvae also become sterile — this stops the pest’s reproduction cycle and prevents it from destroying the next crop.

So recently, when a different pest — the cabbage fly — threatened their daikon crops, Yvon knew to reach out to the Consortium again: they were now conducting research with other farms on using sterile flies for crops in the cabbage family. The Consortium was raising the flies and selling them to producers who needed them. This was a costly process, but based on the success of sterile flies with their onion crops, the owners of Delfland were hopeful that this solution would work again.

Cabbage fly larvae destroy the entire root system by tunnelling through it, which then makes the root vegetable (in this case, the daikon) inedible.

A light at the end of the tunnel

The project would require much time — it would take three to four seasons to achieve optimal effectiveness — and effort to put it in place. Yvon knew they would need help. So, he immediately turned to Lucie Leblanc, his problem-solving sister-in-law and former teacher in agriculture, for her agronomic support. She gladly stepped in to help save the farm’s daikon crops.

Lucie began by mapping out the life-cycle of the flies, noting that there were three “waves” of fly births during the season, each one getting progressively smaller. With a little customization, Lucie was confident they could release groups of sterilized flies in tandem with each wave, allowing only the sterile flies the opportunity to breed. For added protection, Lucie had the idea to cover the crops with nets, ensuring that fewer flies escaped and reducing the risk of fertile flies from breeding, too!

The results were immediate: daikon losses dropped from 50% to 3 – 4% over the course of a single season, and 90% after 4 seasons. Thanks to this technique, they were also able to reduce their use of traditional chemical pesticides by almost 80%, an added benefit for the environment. As Lucie says: “I would love it if people in other provinces were made aware of this pest management technique. What we’ve learned could help other farms across Canada.”

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