Table 1. Experimental design and results for the exposure x postexposure memory and learning trial.
| Run ID | Exposure Time (hours) | Postexposure Time (hours) | Blank Response | α-pinene Response | Preference Index |
|---|---|---|---|---|---|
| 1 | 1.0 | 22.4 | 507 | 244 | 0.481 |
| 2 | 48.0 | 48.0 | 650 | 411 | 0.632 |
| 3 | 48.0 | 32.3 | 246 | 102 | 0.415 |
| 4 | 23.1 | 48.0 | 522 | 505 | 0.967 |
| 5 | 33.8 | 8.1 | 496 | 751 | 1.514 |
| 6 | 1.0 | 22.4 | 604 | 348 | 0.576 |
| 7 | 19.6 | 1.0 | 227 | 390 | 1.718 |
| 8 | 1.0 | 1.0 | 883 | 384 | 0.435 |
| 9 | 1.0 | 1.0 | 560 | 412 | 0.736 |
| 10 | 1.0 | 48.0 | 963 | 1369 | 1.422 |
| 11 | 33.7 | 37.2 | 386 | 538 | 1.394 |
| 12 | 48.0 | 1.0 | 496 | 1131 | 2.280 |
| 13 | 48.0 | 1.0 | 728 | 1796 | 2.467 |
| 14 | 1.0 | 48.0 | 2230 | 876 | 0.393 |
| 15 | 48.0 | 48.0 | 290 | 527 | 1.817 |
| 16 | 24.5 | 24.5 | 204 | 181 | 0.887 |
| 17 | 1.0 | 48.0 | 912 | 647 | 0.709 |
| 18 | 24.5 | 24.5 | 539 | 546 | 1.013 |
| 19 | 13.2 | 14.2 | 382 | 285 | 0.746 |
| 20 | 1.0 | 1.0 | 973 | 678 | 0.697 |
| 21 | 47.5 | 16.7 | 297 | 855 | 2.879 |
| 22 | 24.5 | 24.5 | 395 | 385 | 0.975 |
| 23 | 48.0 | 1.0 | 447 | 677 | 1.515 |
| 24 | 11.6 | 35.3 | 384 | 300 | 0.781 |
| 25 | 24.5 | 24.5 | 729 | 518 | 0.711 |
| 26 | 48.0 | 48.0 | 322 | 419 | 1.301 |
| 27 | 24.5 | 24.5 | 507 | 181 | 0.357 |
The trial is a D-optimal exposure x postexposure response surface design able to detect quadratic curvature for both factors and was developed using Design Expert (version 9.0.4.1; StatEase Inc.). To this design, several additional points were added to aid in estimating model terms and lack of fit. Both factors (exposure, postexposure) were continuous and varied from 1 to 48 hours. S. diaprepesi responses to α-pinene were assayed in two choice, sand-filled olfactometers. The preference index was constructed as the ratio between the numbers of nematodes responding to α-pinene and the number responding to the blank arm.