Burlington forestry have selected Tuesday, June 1 and Wednesday, June 2 to use a low-flying helicopter to apply the second and final dose of bio-pesticide over four wooded areas to control gypsy moth (lymantria dispar dispar, LDD) populations. Gypsy moth caterpillrs eat the leaves of trees, causing significant defoliation and potential long-term impact to the City’s urban forest.
The first application was successfully completed on May 25.
The final application of the pesticide will be completed between 5 and 9 a.m. and is expected to take 5-10 minutes for each park.
The areas identified for spraying include:
City staff will be temporarily preventing vehicles from using roads nearest the spray areas as the helicopter passes. The stoppage will take less than 15 minutes.
An interactive map is available on burlington.ca/gypsymoth that allows residents to enter an address so they can see where the address is in relation to the spray areas.
Steve Robinson, Manager of Urban Forestry said, “for the highest chance of success, the second application should be completed within a 7 to 10-day window of the first application. This fall, we will look at the treated areas to create an estimate of the number of moth egg clusters to determine the success.”
- The City’s contractor will be applying a Class 11 biopesticide, Foray 48B, REGISTRATION NO. 24977 PEST CONTROL PRODUCTS ACT, with active ingredient Bacillus thuringiensis ‘kurstaki’.
- Application of the pesticide with be completed between 5 and 7:30 a.m.
- Bacillus thuringiensis ‘kurstaki’ (Btk) is a soil-borne bacterium that is applied to the leaves of affected trees while caterpillars are in their early stages of development. 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 does not have any negative effects to humans, birds or bees. Btk will affect other caterpillar species (known as non-target species). Due to its low residual nature 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. Residents 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.
- European Gypsy moth, Lymantria dispar, is a non-native invasive pest that was introduced in the late 19th century. It was first discovered in Ontario in the 1960’s and has been a major defoliator of deciduous and coniferous trees across Southern Ontario.
- 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 that have exceeded an action threshold, whereby natural processes can no longer maintain pest population levels on their own. Although healthy trees can generally withstand defoliation several years in a row, trees which are already in distress from problems such as acute drought, compacted soils, diseases or other pests, may decline and die. Generally, healthy trees which are defoliated in spring, will leaf out again by mid-summer. Gypsy moth populations tend to be cyclical, with peaks every 8-12 years, followed by dramatic population decline of the pest.
- The City of Burlington last conducted a similar program in 2019. Program frequency is determined as part of the city’s Integrated Pest Management (IPM) program.