Reminder: One Hour Exam on Monday

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

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

3. 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.

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

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

6. Say we sample at weekly intervals Maximum Tolerable Level Pest Population Density 1 2 3 4 5 6 7 8 Time (Weeks)

7. I Correct decision to control II Incorrect decision to do nothing III Correct decision to do nothing IV Incorrect decision to control You have to make decisions at each sampling date IV Maximum Tolerable Level I Pest Population Density II III III III III 1 2 3 4 5 6 7 8 Time (Weeks)

8. Construction of the decision diagram from sampling data Max Tolerable Pest Pop. IV I II Pest Population Density Pest Population on Next Sample Date I II Max Tolerable Pest Pop. III III IV III III III 1 2 3 4 5 6 7 8 Time (Weeks) Pest Population on One Sample Date Y X

9. Example: Find 15 pest individuals at first sample, 20 on the second sample Max Tolerable Pest Pop. IV I II Pest Population Density Pest Population on Next Sample Date I II Max Tolerable Pest Pop. III III IV III III 20 III 1 2 3 4 5 6 7 8 15 Time (Weeks) Pest Population on One Sample Date 20 15

10. Example: Then, on the third week, we find 40 pest individuals Max Tolerable Pest Pop. IV I II Pest Population Density Pest Population on Next Sample Date I II Max Tolerable Pest Pop. III III IV 40 III III III 1 2 3 4 5 6 7 8 20 Time (Weeks) Pest Population on One Sample Date 40 20

11. Not all decision points are equally susceptible to error IV Maximum Tolerable Level I Pest Population Density II III III III III 1 2 3 4 5 6 7 8 Time (Weeks)

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

13. 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

14. 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