There may soon be a new way to keep unwanted — and harmful — visitors out of vineyards.

While grape mealybugs are commonly treated with a systemic insecticide, research at Brock University’s Cool Climate Oenology and Viticulture Institute (CCOVI) is exploring an alternative to combat the virus-transmitting bugs.

Earlier this year, CCOVI Scientist Malkie Spodek tested the ability of two types of entomopathogenic fungi — Beauveria bassiana and Metarhizium brunneum — to protect vines from grape mealybug infestation. The diverse group of fungi infect and cause diseases in insects, eventually killing them.

Mealybugs — small, soft-bodied insects with a waxy coating — are pests in vineyards, nurseries, greenhouse crops, floriculture and cannabis cultivation.

Cool Climate Oenology and Viticulture Institute Scientist Malkie Spodek stands in the Brock University booth at the 2024 Canadian Greenhouse Conference in Niagara Falls, where she presented the results of her grape mealybug research.

Grape mealybugs, as their name would suggest, have a particular penchant for grape vines. If the insects are infected with grapevine leafroll virus, they transmit the virus to the plant while feeding on its sap. Over time, this can reduce fruit yield and quality as well as vine tolerance to cold temperatures.

The conventional method of controlling grape mealybug infestation in Ontario is to spray vines with the synthetic insecticide Movento.

The advantage of having alternatives is that if insects develop resistance to a systemic insecticide, then growers have nothing to use to protect their vines, says Spodek.

She reached out to Leamington, Ont.-based company Plant Products, which donated two entomopathogenic fungi containing the Beauveria bassiana and Metarhizium brunneum for the research.

When mealybugs come into contact with the fungus sprayed onto the plants, spores attach to their bodies, eventually suffocating them.

“We wanted to show grape growers the evidence that, if this works in our lab and we do subsequent vineyard trials, then they can use these products,” says Spodek.

To test out the products in the lab, she and her team used mealybugs that were collected from one vineyard and reared on sprouted potatoes. Various concentrations of both products were then applied to the potato sprouts where the mealybugs were feeding.

The researchers found both products were active as an mycoinsecticide — insecticides made from fungi — on the mealybugs tested, with higher concentrations being more effective than lower concentrations from Day 2 of the experiment onward.

Fourth-year Biotechnology student Olivia Devries stands next to a research poster presented by Cool Climate Oenology and Viticulture Institute Scientist Malkie Spodek recently at the Annual Entomology Society of Canada meeting in Quebec City.

By the experiment’s end, higher concentrations of Metarhizium brunneum were 90 per cent effective in getting rid of the insects, with Beauveria bassiana having an 80 per cent effectiveness rate.

“The results of this preliminary lab trial are encouraging because we showed that these products have the potential to work against mealybugs,” says Spodek. “More research is needed to test the effectiveness on other mealybug life stages and to test the products in the vineyards.”

Co-funding Spodek’s project, “Laboratory trials of entomopathogens as a biocontrol agent against Grape Mealybug,” are Ontario Grape and Wine Research Inc. (OGWRI) and the Canadian government’s Federal Economic Development Agency for Southern Ontario (FedDev Ontario) channelled through the Greenhouse Technology Network, of which Brock University is a member, and Brock University’s Explore Grant.

Spodek’s team includes CCOVI Principal Scientist Sudarsana Poojari; CCOVI Professional Affiliate and the Ontario Ministry of Agriculture, Food and Agribusiness’ grape and tender fruit specialist Wendy McFadden-Smith; fourth-year Biotechnology undergraduate student Olivia Devries; and CCOVI post-doctoral fellow Bhadra Vemulpati.

Member of Parliament for St. Catharines Chris Bittle says the project is “a wonderful example of Brock University and industry coming together to tackle a challenge that impacts our communities, environment and economy.”

“Dr. Spodek’s research in addressing mealybug infestation is a great boost to Ontario’s grape and wine sector, which has a $5.5-billion economic impact for the province,” says Sam Oosterhoff, Associate Minister of Energy-Intensive Industries and Member of Provincial Parliament for Niagara West.