KPU researchers identify a biological defense against climbing cutworm in Okanagan vineyards.

Researchers at Kwantlen Polytechnic University said Tuesday that they have identified a biological pest-control strategy for vineyards in British Columbia’s Okanagan Valley, where climbing cutworm has been damaging grapevines by feeding on new and developing buds.

The finding comes from a three-year study led by KPU’s Institute for Sustainable Horticulture and Andermatt Canada, a company focused on microbial biopesticides. The research tested four biological control tools in laboratory work and field trials at commercial vineyards across the Okanagan, the province’s largest grape-growing region. The team concluded that no single treatment was enough on its own, but that a combination of parasitoid wasps, nematodes and fungi could suppress the pest when used at the right points in its life cycle.

Climbing cutworm is the caterpillar stage of several moth species. In vineyards, the larvae climb vines and eat buds at a vulnerable stage of plant growth. That can cut yields and lower fruit quality, a direct concern for growers whose grapes are destined for wine production. In a region where vineyard performance shapes both farm revenue and winery supply, a control program that reduces crop losses while limiting chemical use could carry wider implications for the beverage sector, especially for producers trying to build organic or lower-input farming programs.

According to the BC Wine Grape Council, there are 18 known species of climbing cutworm in the Okanagan Valley. Until now, the options for organic growers in British Columbia have been limited. KPU researcher Dr. Sepideh Tahriri Adabi said there are currently no registered biopesticides available to organic wine and grape growers in the province for this pest, leaving many growers dependent on conventional chemical pesticides. That reliance has raised concerns about environmental effects, harm to beneficial organisms and the risk that pests could develop resistance over time.

The new study was designed to see whether biological tools could offer a practical alternative. Researchers evaluated entomopathogenic fungi, insect-specific baculoviruses, entomopathogenic nematodes and parasitoid wasps. The work moved beyond controlled testing and into operating vineyards, where weather, pest timing and field conditions can affect whether a product works as expected.

The results pointed to a timing-based strategy rather than a one-product replacement. Parasitoid wasps were found to be effective from mid-August to mid-September, when they target cutworm eggs before they hatch. Then, from early September to early October, nematodes and fungal pathogens were able to eliminate young larvae that emerged from any eggs that survived. Baculoviruses were included in the study but were not identified by the researchers as part of the final effective combination.

That sequence matters because growers often struggle not only with what to apply, but when to apply it. Adabi said sustainable pest management depends on understanding how pests interact with climate, how biological tools perform under different conditions and how early intervention can prevent damage before it starts. In vineyards, where the timing of bud development and insect feeding can decide the size and quality of a crop, that approach could help managers move from reactive spraying to more targeted prevention.

The research may also open a path toward the future registration and commercialization of new microbial biopesticides in Canada. If those products reach the market, they could expand the tools available to vineyard operators who want to reduce the use of broader chemical pesticides. For wineries, that may eventually mean more flexibility in how grapes are grown, particularly as consumers and export markets pay closer attention to production methods and environmental standards.

The work also reflects a broader shift in grape growing. Vineyard managers across North America have been under pressure to control pests while protecting soil health, pollinators and other beneficial insects. Biological controls are attractive because they can be folded into integrated pest management programs, where multiple tactics are used in sequence instead of depending on repeated chemical applications. In wine regions, those decisions can affect not just farm practices but also how producers position their brands around sustainability.

Several KPU students took part in the project, working in both lab and vineyard settings and contributing to data analysis and scientific communication. Their involvement added a training element to the study at a time when growers and agricultural suppliers are looking for more expertise in biological crop protection.

Adabi said demand for environmentally responsible food production is helping drive fast growth in biological pest-control technologies. She described biopesticides as part of a global industry worth billions of dollars, a sign that interest in alternatives to conventional pesticides is moving from niche farming into the mainstream of commercial agriculture.