Toronto Public Health has provided the following guidelines regarding the use of Merit to control grub infestations under the Pesticide By-law.

The Ontario Ministry of Agriculture, Food and Rural Affairs action thresholds for grubs are accepted as guidelines for the enforcement of the by-law on residential, commercial and institutional turf. These thresholds are 15 larvae/0.1 m2 for irrigated turf and 5-10 larvae/0.1 m2 for non-irrigated turf.

•     Grub infestations must exist on the specific property for which Merit is being considered;
•     In order to apply Merit in a particular year, applicators must observe the presence of grubs at infestation levels for that property for the previous fall or the current spring. (For example, for the upcoming 2006 season, evidence of infestation for fall 2005 or spring 2006 will be required to permit Merit application in 2006.);
•     Applicators should inspect in fall or early spring and prepare written documentation that confirms the presence of an infestation. Documentation should provide a numerical description of grub levels and the location(s) on the property where the assessment was made, along with the date of inspection and name of the technician. It is not necessary to share this information with Toronto Public Health in advance of an application.

Notwithstanding this guidance, inspectors will conduct a thorough investigation for each complaint and may, at their discretion, lay charges if the evidence indicates that the by-law has been violated.

For more information, visit www.toronto.ca/pesticides or call 416-338-7600.