V.) Control Action Guidelines

Question 1

Tolerable Injury Level

Economic Injury Level/Aesthetic Injury Level (Landscapes)

Answer 1

Fundamental to pest management, is the damage level or pest density, where the cost of pest control is less than those inquired through the pest infestation itself.

Based on the perception of the amount of damage the consumer will tolerate.
Or
Based on a processor stipulation. (Example: 2% damage)

Current debate on weeds and pathogens.

Question 2

Treatment Thresholds/ Economic Thresholds

-What is the problem with tolerable injury levels?

Answer 2

-Once pests have reached a certain injury level, it is usually too late for control whereas,

Treatment thresholds: Specify the population density where control measures must be applied to prevent crop loss from damages beyond acceptable levels.
*Efficacy depends on the chosen control measure as well as the pest (ability to build up tolerance).

*Difficult to gauge with pathogens, since most approaches with fungicides tend to be preventative.

Question 3

Control Action Timing

-What is the problem with treatment thresholds?

Answer 3

-For some species, treatment threshold do not always indicate when treatment is most effective. (Example: The most effective treatment timing for many scales is when their populations are low in the dormant season).

Therefore the Control Action Timing defines the optimal time, during the entire season, to take control measures (e.g. independent of harvest period). Based on:

• Crop development
• Pest development
• Environmental conditions