# Reminder: One Hour Exam on Monday Note: I will probably check my email Saturday & Sunday night.

## Presentation on theme: "Reminder: One Hour Exam on Monday Note: I will probably check my email Saturday & Sunday night."— Presentation transcript:

Reminder: One Hour Exam on Monday Note: I will probably check my email Saturday & Sunday night.

Requirements of Monitoring Methods Simple to use Fast Inexpensive Applicable to a broad range of pests Reliable for decision making purposes

Decision-making reliability is crucial Credibility of IPM depends on decisions being correct Decisions have to be made with imperfect information & much of the imperfection is in monitoring data Every decision has a risk of being wrong Lesson: We must understand how frequently our decisions are incorrect and if there is a bias for overcontrol or undercontrol in our mistakes.

Reliability for Decision Tools I II III IV Pest Population on One Sample Date Pest Population on Next Sample Date Max Tolerable Pest Pop.

Consider this situation Maximum Tolerable Level Time (Weeks) Pest Population Density

Say we sample at weekly intervals Maximum Tolerable Level Time (Weeks) Pest Population Density 12345678

You have to make decisions at each sampling date Maximum Tolerable Level I Correct decision to control II Incorrect decision to do nothing III Correct decision to do nothing IV Incorrect decision to control Time (Weeks) Pest Population Density 12345678 III II III I IV III

Construction of the decision diagram from sampling data I II III IV Pest Population on One Sample Date Pest Population on Next Sample Date Max Tolerable Pest Pop. Time (Weeks) Pest Population Density 12345678 III II III I IV III X Y

Example: Find 15 pest individuals at first sample, 20 on the second sample I II III IV Pest Population on One Sample Date Pest Population on Next Sample Date Max Tolerable Pest Pop. Time (Weeks) Pest Population Density 12345678 III II III I IV III 15 20 15 20

Example: Then, on the third week, we find 40 pest individuals I II III IV Pest Population on One Sample Date Pest Population on Next Sample Date Max Tolerable Pest Pop. Time (Weeks) Pest Population Density 12345678 III II III I IV III 20 40

Not all decision points are equally susceptible to error Maximum Tolerable Level Time (Weeks) Pest Population Density 12345678 III II III I IV III

Reliability for Decision Tools I II III IV Pest Population on One Sample Date Pest Population on Next Sample Date Max Tolerable Pest Pop.

Reliability Depends on Several Factors Specific species being monitored Sites (site selection is important) Specific technique being used Number of samples taken –Number at each site & number of sites Weather Observer (Scout) – Scout training is emphasized Other minor effects: –Field size, location, & aspect –Time of day (pests with diurnal activity) –Field history

Some of These are Linked Specific species being monitored Sites (site selection is important) Specific technique being used Number of samples taken –Number at each site & number of sites Weather Observer (Scout) – Scout training is emphasized Other minor effects: –Field size, location, & aspect –Time of day (pests with diurnal activity) –Field history

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