Overview

Ontario Regulation 63/09 (O. Reg. 63/09), made under the Pesticides Act, sets out a class of pesticides that consists of corn and soybean seeds treated with imidacloprid, thiamethoxam or clothianidin. This class is referred to as Class E pesticides. Class E pesticides include corn seeds grown for grain or silage and soybean seed.

In accordance with O. Reg 63/09, Class E pesticides may be used on a farm property where a pest risk assessment report has confirmed that pest numbers, stand loss percentage or pest risk criteria have been met or exceeded, as outlined in this guideline.

Pest risk assessment methods

  • Inspection of Soil assists in determining if pests are present above certain numbers.
  • Inspection of Crop assists in determining if stand loss caused by pests is present above stand loss percentages.
  • Pest Risk Criteria assists in determining if a farm property has factors that increase its risk for pests.

Pest risk assessment report

A pest risk assessment report summarizes relevant information pertaining to the pest risk assessment that was conducted and is required to be completed in order to purchase and use Class E pesticides. The pest risk assessment report only needs to be completed once per farm property. This means the pest risk assessment does not need to be repeated yearly.

If you have previously completed a pest assessment report that was prepared and signed under O. Reg. 63/09 prior to April 9, 2020, you may continue to use that report to purchase and use Class E pesticides.

This document, entitled Pest Risk Assessment Guideline ("the Guideline"), sets out the methods that must be used to perform a pest risk assessment for the purpose of section 3 of O. Reg. 63/09. A pest risk assessment that is not performed in accordance with this Guideline will not meet the legal requirements of O. Reg. 63/09.

As set out in paragraph 3 of subsection 3 (1) of O. Reg. 63/09, a pest risk assessment report must confirm one of the following:

  • Pest Risk Assessment Method 1 – Inspection of soil: An inspection of the soil was conducted at the farm property in accordance with the Pest Risk Assessment Guideline and the presence of one or more of the pests referred to in the Guideline was detected in a number that was equal to or greater than the applicable number required to be detected under the Guideline in order to use a Class E pesticide.
  • Pest Risk Assessment Method 2 – Inspection of a crop: An inspection of a crop was conducted at the farm property in accordance with the Pest Risk Assessment Guideline and the inspection detected a percentage of stand loss caused by one or more of the pests referred to in the Guideline that was equal to or greater than the applicable percentage required to be detected under the Guideline in order to use a Class E pesticide.
  • Pest Risk Assessment Method 3 – Pest Risk Criteria: An assessment was conducted at the farm property and one or more of the pest risk criteria set out in the Pest Risk Assessment Guideline were met.

This Guideline sets out:

  • the types of pests to look for when conducting an inspection of soil
  • the numbers of pests that must be present or percentage of stand loss caused by those pests in order to be allowed to use a Class E pesticide at the farm property
  • the steps required to be taken to perform a pest risk assessment by an inspection of soil to determine the presence of those pests (Method 1)
  • the steps required to be taken to perform a pest risk assessment by an inspection of a crop to determine percentage of stand loss (Method 2) caused by those pests
  • the pest risk criteria list to determine a farm property is at an increased risk for pests (Method 3)

Definitions

In this Guideline,

"bean leaf beetle"
means the bean leaf beetle when in its adult life stage;
"corn rootworm"
means any of the following species of insects when in their larval life stage:
  1. Northern corn rootworm
  2. Western corn rootworm
"grub"
means any of the following species of insects when in their larval life stage:
  1. European chafer
  2. Japanese beetle
  3. June beetle
"Regulation"
means Ontario Regulation 63/09 (General) made under the Pesticides Act
"wireworm"
means click beetle when in its larval life stage.

For ease of reference, it is noted that O. Reg. 63/09 provides the following definitions of terms that are used in this Guideline:

"farm property"
means an area of land used for an agricultural operation, part of an agricultural operation or more than one agricultural operation
"stand loss"
means crop damage, such as,
  • the failure of plants to emerge; or
  • stunted, damaged or dead plants that occur as the result of a lack of plant vigour

Pests

When conducting an inspection of soil, one or more of the following pests must be detected:

  • grub
  • wireworm

When conducting an inspection of a soybean crop, the stand loss must be caused by one or more of the following pests:

  • grub
  • wireworm
  • seedcorn maggot
  • bean leaf beetle

When conducting an inspection of a corn crop, the stand loss must be caused by one or more of the following pests:

  • grub
  • wireworm
  • corn rootworm
  • seedcorn maggot

Thresholds for use of a Class E pesticide

Number of pests detected

An average of 2 grubs per scouting location averaged over 5 scouting locations must be detected.

An average of 1 wireworm per scouting location averaged over 5 scouting locations must be detected.

Percentage stand loss

The percentage stand loss for a corn crop is 15 percent.

The percentage stand loss for a soybean crop is 30 percent.

Pest risk assessment method 1 - Inspection of soil

An inspection of soil is used to determine whether there are grubs or wireworms present at a farm property in a number that meets or exceeds the numbers set out in this Guideline. The following steps must be taken in order to perform an inspection of soil:

  1. The first step is to identify at least five locations in which to scout for grubs or wireworms. Each location must be at least 10 metres away in all directions from any other location.
  2. The second step is to perform scouting in each location identified in Step 1. Scout for grubs using the digging scouting technique described below. Scout for wireworms using either the digging scouting technique, or the bait trap scouting technique described below.
    1. Digging Scouting Technique

      Dig a hole with a surface area of approximately 30 cm by 30 cm to a depth of 7cm - 10 cm and sift through the soil removed from the hole, breaking up any clumps of soil to observe any grubs or wireworms within the soil and hole. Count and record the number of grubs and wireworms observed in the soil and hole in each of the locations.

    2. Bait Trap Scouting Technique

      Dig a hole with a surface area of approximately 15 cm by 15 cm to a depth of approximately 15 cm and place approximately 1 cup of bait into the hole. Fill in the hole with soil, breaking up any clumps of soil to cover the bait. Mound the soil to prevent standing water. You may wish to place a flag at the location of the hole to ensure finding the hole later. Seven to 10 days after preparing the bait trap, dig out the bait to observe any wireworms. Count and record the number of wireworms observed in each of the locations.

      Examples of bait include, but are not limited to:

      • 1 cup of equal parts of soaked untreated corn seed and untreated wheat seed
      • 1 cup of flour
      • 1 cup of freshly cut potatoes
  3. After the scouting set out in Step 2 is performed at each of the locations identified in Step 1, the third step is to calculate the average number of grubs and wireworms per scouting location identified in Step 1.
    • To calculate the average number of grubs, add together the number of grubs observed in five scouting locations and divide by five.
    • To calculate the average number of wireworms, add together the number of wireworms observed in five scouting locations and divide by five.

A Class E pesticide may be used at the farm property provided that the Pest Risk Assessment Report indicates that:

  1. the average number of grubs observed in the five scouting locations within the area is 2 or greater; or
  2. the average number of wireworms observed in the five scouting locations within the area is 1 or greater.

A farm property that meets the above-mentioned criteria must be sketched, clearly indicating the scouting locations, in a pest risk assessment report prepared for the purposes of section 3 of the Regulation.

Pest risk assessment method 2 - Inspection of a crop

The objective of Pest Risk Assessment Method 2, inspection of a crop, is to determine whether the stand loss in a corn or soybean crop that was caused by one or more of the pests set out in this Guideline meets or exceeds the percentage of stand loss set out in this Guideline for that crop.

In particular, the steps set out for Pest Risk Assessment Method 2 shall be performed to determine whether:

  • damage to corn plants was caused by one or more of the following pests: grubs, wireworms, seedcorn maggots or corn rootworms; or
  • damage to soybean plants was caused by one or more of the following pests: grubs, wireworms, seedcorn maggots or bean leaf beetles.

The following steps must be taken in order to perform an inspection of crop:

  1. The first step is to identify an area on the farm property on which corn or soybean crops were planted with seed that is not a Class E pesticide in which stand loss is detected.
  2. The second step is to identify, for the area identified in Step 1, at least five locations in which:

    • to inspect for stand loss ("stand loss location"); and
    • there is no stand loss evident ("non-stand loss location").

    The following criteria must also be met:

    1. The number of non-stand loss locations identified must be the same as the number of stand loss locations identified.
    2. Each location must be at least 10 metres away in all directions from any other location.
    3. The size of each location planted with corn shall be determined using the Row Plant Technique set out in Appendix 1 of this Guideline.
    4. The size of each location planted with soybean shall be determined using either the Row Plant Technique or the Quadrat Technique set out in Appendix 1 of this Guideline.
  3. The third step is to inspect the corn or soybean crop in each stand loss location identified in Step 2 for stand loss. If stand loss is found, determine if it was caused in each location by one or more of the following pests:

    • grubs, wireworms, seedcorn maggots or corn rootworms in corn plants; or
    • grubs, wireworms, seedcorn maggots or bean leaf beetles in soybean plants.

    Record the rationale for determining which type of pests caused the stand loss.

  4. If the stand loss was caused by one or more of the pests mentioned in Step 3, the fourth step is to determine and record the average number of unaffected plants per acre in the stand loss locations identified in Step 2. To do so, count and record the number of plants that are unaffected, i.e. not stunted, damaged or dead, in each stand loss location identified in Step 2 using the counting methods set out below. Average the number of unaffected plants per acre/ha determined for each stand loss location and record. Counting shall be performed using the following techniques:
    • Corn plants shall be counted using the Row Plant Technique set out in Appendix 1 of this Guideline.
    • Soybean plants shall be counted using either the Row Plant Technique or the Quadrat Technique set out in Appendix 1 of this Guideline.
  5. The fifth step is to determine and record the average number of plants per acre/ha in the non-stand loss locations identified in Step 2.

    • For corn, you may use the Row Plant Technique mentioned in Step 4 or by using the planting rate used to plant the corn crop.
    • For soybean, you may use the same counting technique that was used to count the number of unaffected plants per acre/ha in stand loss locations in Step 4.

    If a counting technique is used, count and record the number of unaffected plants in each non-stand loss location identified in Step 2 and average and record the number of unaffected plants per acre/ha determined for each non-stand loss location.

  6. The sixth step is to calculate and record the percentage of stand loss at the farm property in accordance with the following equation:

    [(X − Y) ÷ X] × 100 = % Stand Loss

    Where,
    X is the average number of plants per acre/ha in the non-stand loss locations as determined in Step 5; and
    Y is the average number of plants per acre/ha in the stand loss locations as determined in Step 4.

    This step will provide:

    • For corn: The percentage of stand loss caused by grubs, wireworms, seedcorn maggots or corn rootworms at the farm property
    • For soybean: The percentage of stand loss caused by grubs, wireworms, seedcorn maggots or bean leaf beetles at the farm property.

    A Class E pesticide may be used at a farm property if the Pest Risk Assessment Report indicates that the percentage of stand loss in a corn crop or soybean crop calculated in Step 6 meets or exceeds the following:

    1. 15 per cent if the stand loss calculated is in respect of a corn crop;
    2. 30 per cent if the stand loss calculated is in respect of a soybean crop.

A farm property that meets this criteria must be sketched, clearly indicating the scouting locations that were inspected for stand loss and no stand loss, in a pest risk assessment report prepared for the purposes of section 3 of the Regulation.

Pest risk assessment method 3 – Pest risk criteria

The objective of Pest Risk Assessment Method 3 is to determine whether a farm property has certain characteristics that would indicate that it is at increased risk of having grubs or wireworms present.

In order to perform the pest risk assessment for corn and soybean:

1. Determine if the farm property meets any of the following pest risk criteria:

  • The soil of the farm property is sandy or silty, there are hilly knolls on the farm property and there are treelines that border the farm property.
  • The soil of the farm property is sandy or silty and there are frequent grass crop rotations (e.g. cereals, mixed forages, newly broken sod) on the farm property.
  • The soil of the farm property is sandy, silty or muck and there are frequent grass crop (e.g. cereals, mixed forages, grassy weeds, newly broken sod), canola or vegetable crop (e.g. carrots, sugar beets, sweet potatoes and potatoes) rotations on the farm property.
  • The soil of the farm property is sandy, silty or muck, there is grassy/cereal crop cover and reduced tillage methods used at the farm property.
  • The soil of the farm property is sandy, silty or muck and the farm property has been pasture or fallow for the previous two years.
  • The farm property is adjacent to a pasture, sod farm, parkland or golf course.
  • The farm property has soil containing greater than 10 per cent organic matter.
  • The farm property had an infestation of grubs or wireworms in the previous three-year period.

If the pest risk assessment report indicates that one or more risk factors on the farm property are met, a Class E pesticide may be used.

Appendix 1

Plant counting techniques

As mentioned above, either the row plant technique or the quadrant technique must be used to count the number of plants in a stand loss location.The steps for each technique are set out below.

Row Plant Technique

  1. For row crops, measure the row width to determine the length of row that needs to be measured for the assessment.
  2. Choose the row length that is set out in Table 1 opposite the row width measured in Step 1 of this counting technique. For example, if a row width of 76 cm was measured, the length of the row in which to count plants would be 5.3 m.
  3. Count the number of plants in the row length indicated in Table 1 to determine a plant population per thousandth of an acre (1/1000).
  4. To calculate the number of plants per acre, multiply the number calculated in Step 3 by 1000. To calculate the number of plants per hectare, multiple the number of plants in the length of the row by 2.47 and then by 1000.
Table 1 - Determining number of plants/acre in various row widths
Row Width: centimetresRow Width: inchesLength of Row Equal to 1/1000 acre in metresLength of Row Equal to 1/1000 acre in feet
381510.634 ft. 10 in.
51208.026 ft. 1 in.
56227.323 ft. 10 in.
71285.718 ft. 8 in.
76305.317 ft. 5 in.
81325.016 ft. 4 in.
86344.715 ft. 5 in.
91364.414 ft. 6 in.
97384.213 ft. 9 in.

Quadrat Technique

  1. Count the number of plants within a hoop or square frame of dimensions set out in Table 2.
  2. Multiply the number of plants counted within the hoop or square frame by the factor set out in Column 3 opposite the inside diameter of the hoop or inside dimension of the frame used for the count set out in Column 1 of Table 2 to determine plant population per hectare or acre.
Table 2 - Determining number of plants per acre/hectare
Inside Diameter of Hoop in Centimetres (inches)Area in m2 (ft2)Factor by Which to Multiply the Number of Plants within the Hoop to Equal: Plants per HectareFactor by Which to Multiply the Number of Plants within the Hoop to Equal: Plants per Acre
91 (36)0.65 (7.0)15,3856,165
84 (33)0.55 (6.0)18,1827,334
76 (30)0.45 (4.9)22,2228,874
69 (27)0.37 (4.0)27,02710,956
61 (24)0.29 (3.2)34,48313,865
Table 2 - Determining number of plants per acre/hectare
Inside Dimensions of Square Frame in Centimetres (inches)Area in m2 (ft2)Factor by Which to Multiply the Number of Plants within the Square to Equal: Plants per HectareFactor by Which to Multiply the Number of Plants within the Square to Equal: Plants per Acre
50 × 50 (20 × 20)0.25 (2.7)40,00016,133
100 × 100(40 × 40)1.00 (11.1)10,0003,924