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Ministry of Agriculture, Food and Rural Affairs

How to Scout

Systematic monitoring of pest populations, weather conditions, plant health and disease symptoms are critical components of an IPM program.

Tools needed to monitor pests

  • a 16-20x hand lens
  • traps (pheromone traps and yellow sticky cards with bait)
  • tapping trays
  • collection bags and vials
  • field maps
  • flagging tape
  • shovel or sturdy trowel
  • pocket knife
  • scouting forms and record sheets
  • weather loggers
  • resources such as OMAFRA Publication 360, Fruit Production Recommendations

Monitoring strategies

  • Review pest control calendars to know when certain pests will be active.
  • Learn to identify life stages and damage caused by diseases and pests.
  • Understand the biology and life cycle of pests and diseases.
  • Recognize beneficial insects, as well as harmless insects.
  • Use historical data to identify hot spots and previous problems.
  • Keep a field map and record the location of damage.
  • For each visit, record the stage of crop development, disease severity, population levels of insect pests and beneficials, and damage observed.
  • Keep a journal or log of rainfall amounts, daily highs and lows, and weather events.
  • Keep a record of pesticides applied and other control measures used.

Monitoring procedures

  • Monitor at least once a week and preferable twice a week during critical stages.
  • Monitor at approximately the same time each day and keep the light behind you.
  • Inspect plants in several areas across the field to get an accurate idea of pest pressure.
  • Stand back and look for patterns, such as patches or areas or poor plant growth or where colour is off.
  • Get close and examine fruit clusters, the underside of leaves and inside the canopy, etc.
  • Scout the edges of the field and interior of the field separately.
    Give special attention to border areas.

Sample collection involves the collection of data to represent the entire area being monitored.

  • Divide large areas into sample blocks.
  • Walk in a W or zig-zag pattern across the field to collect samples from a representative area.
  • Look away from the plant when you take samples of leaves and fruit, etc., otherwise you will tend to choose damage leaves or fruit and bias the sample.

Techniques used in Monitoring pests

Trapping: Provides information on insect numbers and activity. Can be used to validate degree day models, which predict insect life stage. Optimize management techniques.

Pheromone traps: Use pheromone traps to determine the presence or absence of pests and the first sustained flight or peak activity of certain pests. This information is used in conjunction with degree day models to predict when egg hatch begins, and determine the best timing for control measures. Pheromone traps are used to monitor for oriental fruit moth, codling moth, obliquebanded leafroller, dogwood borer and spotted tentiform leafminer (optional) in apples. Guidelines on using pheromone and visual traps in orchards have been established.

Visual attractants: Yellow sticky boards and three-dimensional (3D) white sticky cards are attractive to certain insects because they provide a visual stimulus. They are used to indicate the presence and relative abundance of a pest (apple maggot or European apple sawfly).

Tapping: Tapping is an excellent tool for monitoring mullein bugs, spring feeding caterpillars and other early season pests. The presence of beneficial insects can also be monitored by tapping. The tapping tray is held beneath the branch and rapped sharply with a padded stick. Two or three raps on a single branch dislodges insects onto the tray where they can be observed or counted.

Visual observation: Visual observations provide inforamtion on the presence and absence of pests and beneficial insects. When scouting apples monitor terminals and fruit buds for the presence of aphids, leafrollers, and beneficial insects. Monitor for damage from pests, since often the pest is long gone, but the damage remains. Conduct random fruit assessments to detect damage from codling moth, oriental fruit moth, leafrollers, apple maggot, etc.

Scouting in apples Scouting in apples Trap
Click to enlarge.