The cannabis aphid (Phorodon cannabis) and root aphid (Rhopalosiphum rufiabdominalis) are ubiquitous pests of cannabis cultivation. These culprits are capable of taking out entire crops, affecting cannabis plant growth, or at the very least, causing an inferior product. It’s a major concern for the commercial cannabis industry, which currently struggles to manage it.
The integrated pest management (IPM) of these bugs is tricky for several reasons. There’s a lack of scientific research around pest management in cannabis, as this crop has become legalized only recently. Also, pesticide options for controlling these aphids are extremely limited as the use of synthetic insecticides is not allowed in the cannabis industry.
A common intervention for aphid control in conventional crops is biological control – the use of beneficial/predatory insects – which chase off or kill aphids without damaging the plants.
However, up until now, aphid biocontrol has not been successful for cannabis crops, due to a lack of performance, so the challenge is to find an efficient predatory insect to do the job.
At Vineland Research and Innovation Centre (Vineland), one of its research programs supports the use of biological control strategies. The program is led by research scientist and program leader Rose Buitenhuis, PhD.
“In recent years, Vineland has undertaken extensive research trials to determine the potential of a native predatory mite species as a new biocontrol agent. The predator was discovered in St. Catharines by Taro Saito, a senior research technician at Vineland, who has studied its predation potential and developed a mass rearing system,” says Buitenhuis. “Vineland has now partnered with the Canadian biocontrol supply company Applied Bionomics in North Saanich, B.C., to bring it to market.”
“Participating in a course-based research project to contribute data for a promising, and locally developed, new biocontrol agent in the cannabis industry was a highlight of my first term…”
~ NC student Deana Huntsbarger
Vineland partnered with Niagara College’s Agriculture & Environmental Technologies Innovation Centre (AETIC) in a course-based project headed by NC’s Sebastien Jacob, a professor in the Greenhouse, Horticulture and Commercial Cannabis Production programs, to test the efficacy of Vineland’s new predatory mite.
Before now, no scientific studies have ever tested the potential of Vineland’s mite on cannabis plants.
“There are several reasons that may explain the lack of efficacy of current, and future, biocontrol agents against these pests on cannabis, but none of them has been researched yet. For example, the presence of non-glandular and glandular trichomes on the plant’s surfaces or the production of plant semiochemicals (terpenes) could have a detrimental effect on predator population establishment on cannabis plants,” explains Jacob. “If the new predatory mite is not hampered by these factors, then we are looking forward to further research collaboration, for the industry and for hands-on learning experiences to our students.”
The objective, continues Buitenhuis, was to determine if the new predatory mite can survive and reproduce, on Cannabis sativa plants as well as on the control plant Chrysanthemums when fed an unlimited supply of artificial food.
The trial was conducted in the Niagara College ‘CannaBunker’ by a fall 2020 cohort of students within the course Entomology and IPM of the Commercial Cannabis Production program, under the supervision of Jacob.
Two treatments (Cannabis sativa, Chrysanthemum) of 12 plants each were completely randomized on an Ebb and Flow growing bench. The predatory mites were released on each plant which were grown in vegetative growing conditions for eight weeks. Each week, the number, location and stage of the mite were counted and noted.
The results, says Jacob, look highly encouraging.
“Vineland’s predatory mite successfully reproduced and developed on cannabis plants … this is really promising news,” he explains.
For the NC students, working on the predatory mite trial gave them a unique opportunity to conduct real-world research with enormous benefit for the cannabis industry.
“Participating in a course-based research project to contribute data for a promising, and locally developed, new biocontrol agent in the cannabis industry was a highlight of my first term, connecting me to innovations in my field while still in the classroom,” says student Deana Huntsbarger.
“It was truly an enjoyable and fascinating experience from start to finish,” adds Wyatt Scheller. “I’m very grateful for the opportunity to have been a part of this research and I am excited to learn more about the potential benefits this predatory mite could provide growers in the cannabis industry moving forward.”P
Buitenhuis says that with the positive results of the trial, Vineland is eager to collaborate with the College for more research in the future.
“Niagara College was easy to work with and the professor, technician and students were committed to delivering the best results. As such, they put in a lot of work and long hours, not an easy task during the COVID-19 pandemic.”
Niagara College’s AETIC team works with private and public sector partners to develop innovative solutions to address today’s challenges in agriculture, local and sustainable food production, plant growth, horticulture practices, greenhouse operations, aquaponics and environmental management.
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