Public Notice of Pesticide Use for Gypsy Moth Control
| The second and final aerial spray for Kerncliff/Forestvale, LaSalle, Mountainside and Lowville Parks was completed on Saturday, June 8. Forestry staff will continue to monitor the areas, and all wooded areas within Burlington, for gypsy moth growth and work to protect the City's trees to ensure we have strong, healthy trees for generations to come. |
The City of Burlington will be administering a Gypsy Moth Control Program by applying a bio-pesticide by helicopter to areas within Burlington. The helicopter will be flying at low altitudes, approximately 15 metres above tree tops, between approximately 5 and 7:30 a.m.
The following pesticide will be used: Foray 48B Biological Insecticide Aqueous Suspension (Bacillus thuringiensis subsp. kurstaki strain ABTS-351) Registration No. 24977 under the Pest Control Products Act (Canada). The spray program will occur over two days between May and June, 2019. The exact dates and time for the aerial spray are weather dependent. The City will provide up-to-date details on this page and through Twitter and Facebook once the dates have been confirmed.
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What is Gypsy Moth?
European Gypsy moth, Lymantria dispar, is an introduced pest that impacts trees when larvae emerge in spring and the caterpillars feed on leaves causing defoliation. Oaks are the preferred host species of tree.
As part of Burlington's Integrated Pest Management (IPM) program, Forestry staff assess sites annually across the city and conduct egg mass surveys to determine areas where natural processes can no longer keep pest population levels down on their own. Although healthy trees can generally withstand repeated defoliation, trees which are already in distress from problems such as acute drought, compacted soils, diseases or other pests may die. Generally, healthy trees which are defoliated in spring, will leaf out again by fall. Gypsy moth populations tend to be cyclical, with peaks every 8-12 years, followed by dramatic population decline of the pest.
Treatments are only used when populations exceed accepted thresholds. Treatment of the insect is aimed at keeping larvae populations below threshold levels. The treatment option commonly used is Btk (Bacillus thuringiensis var. kurstaki), a bacterium found naturally in soils. Btk works only against the larvae of the target species of insect; it does not affect plants, animals or people. Btk is one of the few treatments acceptable to organic growers as it is a naturally occurring biological organism.
Gypsy Moth Treatment Area
120 hectares will be sprayed.
Parks include:
- Lowville Park
- LaSalle Park
- Kerncliff/Forestvale Park
- Mountainside Park
To see where the spraying areas are, see the map below.
| Why it Matters |
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The City of Burlington is committed to a healthy and green city. The City of Burlington has identified four wooded areas within the city that have high amounts of gypsy moth egg clusters and are at significant risk of permanent damage if action is not taken. When gypsy moth larvae (caterpillars) hatch from their eggs in early spring, they eat the leaves of the tree, which causes defoliation. Trees are forced to “push” a second set of leaves which depletes nutrient stores within the tree. Repeated defoliation for several years causes significant stress to trees and in some cases, can kill part or all of the tree. This is particularly important to urban trees that are growing in tougher conditions (less water, compacted soils, hotter). The four locations in Burlington have egg masses that are well above the normal level and are at risk of significant defoliation. As a result, 120 hectares will be sprayed with a naturally occurring pesticide from helicopter flying at low altitude to help reduce gypsy moth populations below threshold levels. The naturally-occurring, biological pesticide, BtK, being used is not harmful to humans or animals, including pets and degrades in the natural environment within 1-4 days. See “About the Biological Pesticide” below for more information. |
| About the Biological Pesticide |
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Bacillus thuringiensis ‘kurstaki’ (Btk) is a soil-borne bacteria that is applied to the leaves of affected trees while caterpillars are in their early instar stage (immature). Once ingested, the bacterium disrupts the caterpillars’ digestive system with cessation of eating within 24-48 hours. Within days, caterpillars that have ingested Btk will succumb to its effects. Btk has very low residual qualities in the natural environment. Sunlight and fungi deteriorate the bio-pesticide within 1 to 4 days. Because Btk requires an alkaline environment in the gut in order to be effective, it does not have any detrimental effects to humans, birds or bees. Btk will affect other caterpillar species (known as non-target species). Due to its low residual and the narrow spray window due to larval development, the non-target impact is expected to be low. Individuals who have concerns should take reasonable precautions to avoid exposure during a spray program in the same way they would avoid pollen or other airborne materials during days when air quality advisories are issued. They can also reduce exposure by staying indoors with windows and doors shut during the spray period if spraying is taking place in their area, although this is not required by health officials. (Health Canada, 2009) |
| Who to Contact |
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For questions or concerns, please contact Brianna Thornborrow, Supervisor of Forest Planning and Health at brianna.thornborrow@burlington.ca or 905-333-6166, ext. 6145. |