Implementation of biological control for introduced Phragmites in Canada

Introduced Phragmites, Phragmites australis australis, is one of the most invasive plants in North America. Traditional control methods such as manual removal and the use of herbicides are impractical in many locations, and are prohibitively expensive to implement on a landscape scale. Classical biological control represents an affordable, host-specific, and sustainable tool to supplement these existing management options.

Two European stem boring moths, Archanara neurica (Hübner) and Lenisa geminipuncta (Haworth) (Lepidoptera: Noctuidae), were approved for release in Canada in 2019. Since that time, an operational protocol for the rearing, release, and monitoring of these insects has been developed. To date, over 23,000 moths have been released across 30 sites in Ontario. Post release monitoring has been conducted in all cases, and insect damage has been detected in 27 of the 30 sites. At sites that are two or three years post-release, damage has been observed each year, indicating initial biocontrol agent overwintering and reproduction. Preliminary monitoring has also detected negative impacts on introduced Phragmites in the area surrounding biological control agent releases. These impacts include reduced stem density, reduced average stem height, and impaired panicle formation.

In this talk I will discuss the current status of the Phragmites biological control program in Canada, and outline plans to scale up the release program through the establishment of nurse sites across the province. Additionally, I will discuss the development of new techniques for monitoring the biological control agents and their impacts, including the use of pheromone traps and drone technology.