Aerial spray may be required in selected areas to combat Jack Pine Budworm infestation

Reeti Meenakshi Rohilla - Staff Writer

Jack Pine Budworms continue to infest large areas of Red Lake, Kenora, Dryden and Sioux Lookout Districts. After cancellation due to unseen circumstances of the pandemic, the Ministry of Natural Resources and Forestry is now resuming work to assess the affected areas. This will help determine if an aerial spray program may be implemented in 2021.
According to the Environmental Registry of Ontario, the latest wave of this infestation started in 2017, and since then, it has damaged approximately 1,033,378 hectares of forest in Northwestern Ontario. Last year a pest management program was implemented that treated around 100,000 hectares of the infestation from 2018.
The Jack Pine Budworm infestation in the forests of Sioux Lookout, Kenora, Dryden and Red Lake areas are currently moderate to severe.
Earlier this year, development of an Insect Pest Management Program was proposed to be carried out to fight the rising population of this pest. However, the Ministry of Natural Resources and Forestry was forced to cancel the program that would have aerial sprayed 80-thousand hectares of forest in the Kenora District most heavily affected, using a biodegradable insecticide known as BTK to control it. Due to the COVID-19 pandemic, the ministry advised that the project team might not be able to consistently follow the recommended social distancing measures during operations.  
Dan Rowlinson, the Forest Head Field Coordinator for the Ministry of Natural Resources and Forestry said, “It runs over a course of about 3-5 years and we’re entering into year three of the infestation.” He added that it is a part of our natural landscape. It heavily impacts the jack pine species.
“It’s not just the value of that tree from a wood supply perspective, but also the tourist industry and the community. People like their green spaces and we want to make sure that these trees are kept green throughout this natural cycle of the budworm,” he said.
These tiny, reddish-brown native insects that primarily feed on jack pines cause widespread defoliation, growth loss, top kill and tree mortality. The pest, however, might also attack and maintain outbreak populations in white pine and red pine stands. Every eight to 10 years, approximately, the species is known to periodically reach outbreak levels in Ontario.
“What that color in fact is on the trees is that Jack Pine Budworm is a very messy feeder, so when it chews needles off, it eats part of the needle and ties them up in webbing. It starts to dry out in the summer turning them red,” said Rowlinson.
With the majority of feeding done during late June and early July, the mature larvae soon lay eggs on needles in masses of two or three overlapping rows. The eggs usually hatch within 10 days and are ready to find safe areas under the bark to spend winter covered in a silken web called hibernacula.
Using scientific information and knowledge based on past outbreaks, advantages and disadvantages of each type of forest management options were taken into account. Considering the severity and the extent of the spread of this infestation, the planning team concluded that an aerial spray of insecticides may be required in selected areas.
However, this program is highly demanding of time, along with being expensive and complexly strategic. There exists a very narrow time window of about two weeks during early July when the aerial spray must take place. The most highly affected areas were on the list of this program to protect the wood supply and further reduce risks of forest fires.
“We did the aerial survey this season and are currently working on completing and clearing the data collected. We fly over the defoliated areas, mapping the damaged one. This information will be further used to support the planning process for 2021, and to determine if need be for another type of management response or intervention is required,” Rowlinson informed.