Vineland Research

Assessment of the potential of a new predatory mite to persist on cannabis plants


The commercial cannabis industry currently struggles with integrated pest management (IPM) of the cannabis aphid Phorodon cannabis, and the rice root aphid, Rhopalosiphum rufiabdominalis,  and many licensed producers have lost yield or even their entire crop to these pests. The current IPM approaches available to the industry simply lack in efficacy. Several factors (ie cuticular ridges, glandular and non-glandular trichomes, plant semiochemicals interfering with searching behavior, aphid auto immune system, etc.) could explain this lack of efficacy, all of which have yet been studied. Research is needed to understand these factors, or better yet, to discover new biological control agents that aren’t affected by them and that have a higher efficacy against this devastating cannabis aphid pest.

In recent years, Vineland Research and Innovation Centre (Vineland) has been developing a native beneficial predatory mite, and the results are promising. Vineland has now partnered with the Canadian biocontrol supply company Applied Bionomics in North Saanich, B.C., to bring it to market. However, all the reasons explained above could also be detrimental to the efficacy of this new mite on cannabis plants. Since this mite can survive and establish in a crop when provided with an unlimited supplemental food, the main objective of this work, as a course-based research project, was to determine if the predatory mite can survive, and reproduce, on Cannabis sativa plants, when provided with unlimited access to an alternate food source. Two types of plants, cannabis and chrysanthemum, were evaluated as treatments. Overall, similar proportions of mites were observed on both treatments during each week of the trial. By the end, a destructive final count showed slightly more mites on chrysanthemum foliage, along with more mites on cannabis plants at soil level. In conclusion, the mites did establish successfully and completed their development on both crops, and population levels were associated with the presence and location of live available prey.