Table 1.
Regression estimates for median lethal concentration assays (LC50) resulting from topical bioassays of adult L. decemlineata for the Arlington Agricultural Research Station (AARS), imidacloprid‐susceptible and Systemic‐3, imidacloprid‐resistant populations during summer 2015
| Population | Assay date | N | LC50 (µg µL−1) | 95% CIa | χ 2 b | PR > χ 2 |
|---|---|---|---|---|---|---|
| Early emergence | ||||||
| Arlington | 9 June | 225 | 0.0052 | (0.00051–0.021) | 19.43 | <0.0001 |
| Arlington | 13 June | 225 | 0.058 | (0.0015–0.61) | 8.35 | 0.0038 |
| Arlington | 21 June | 270 | 0.15 | (0.0100.73) | 11.47 | 0.0007 |
| Arlington | 25 June | 270 | 0.099 | (NA*) | 3.80 | 0.051 |
| Arlington | 29 June | 180 | 0.021 | (NA*–0.14) | 11.62 | 0.0006 |
| Systemic‐3 | 9 June | 225 | 1.5 | (0.18–19) | 7.28 | 0.007 |
| Systemic‐3 | 13 June | 225 | 3.5 | (1.1–53) | 13.54 | 0.0002 |
| Systemic‐3 | 21 June | 270 | 7.5 | (3.0–49) | 19.53 | <0.0001 |
| Systemic‐3 | 25 June | 270 | 7.5 | (4.5–19) | 26.29 | <0.0001 |
| Systemic‐3 | 29 June | 180 | 2.4 | (1.6–3.8) | 32.28 | <0.0001 |
| Late emergence | ||||||
| Arlington | 25 June | 270 | 0.18 | (0.13–0.24) | 23.79 | <0.0001 |
| Arlington | 29 June | 270 | 0.23 | (0.067–0.68) | 11.56 | 0.0007 |
| Arlington | 3 July | 270 | 0.073 | (NA*–0.24) | 4.96 | 0.030 |
| Arlington | 6 July | 270 | 0.099 | (0.0059–0.40) | 10.50 | 0.0012 |
| Arlington | 10 July | 270 | 0.11 | (0.015–0.55) | 14.31 | 0.0002 |
| Arlington | 14 July | 90 | 0.18 | (0.020–13) | 8.73 | 0.0031 |
| Systemic‐3 | 25 June | 270 | 6.8 | (5.5–10) | 11.11 | 0.0009 |
| Systemic‐3 | 29 June | 270 | 8.7 | (6.3–30) | 8.29 | 0.004 |
| Systemic‐3 | 3 July | 270 | 8.7 | (6.0–13.9) | 9.84 | 0.0017 |
| Systemic‐3 | 6 July | 270 | 11 | (4.7–40) | 4.79 | 0.028 |
| Systemic‐3 | 10 July | 270 | 9.0 | (2.4–15) | 5.62 | 0.017 |
| Systemic‐3 | 14 July | 180 | 4.1 | (3.1–5.5) | 46.31 | <0.0001 |
| Conclusion of first generation | ||||||
| Arlington | 10 July | 180 | 0.18 | (0.12–0.27) | 20.73 | <0.0001 |
| Arlington | 14 July | 180 | 0.14 | (0.063–0.36) | 28.32 | <0.0001 |
| Arlington | 18 July | 90 | 0.030 | (NA*) | 2.68 | 0.10 |
| Sytemic‐3 | 10 July | 180 | 5.7 | (4.2–8.9) | 29.14 | <0.0001 |
| Sytemic‐3 | 14 July | 180 | 8.7 | (0.050–23) | 4,7 | 0.03 |
| Sytemic‐3 | 18 July | 90 | 5.3 | (3.7–8.3) | 19.81 | <0.0001 |
| Second generation | ||||||
| Arlington | 21 July | 270 | 0.28 | (0.016–1.3) | 5.65 | 0.017 |
| Systemic‐3 | 21 July | 270 | 8.4 | (4.1–20) | 19.18 | <0.0001 |
| Systemic‐3 | 27 August | 270 | 15 | (7.0–28) | 16.58 | <0.0001 |
| Systemic‐3 | 10 September | 270 | 14 | (4.9–28) | 13.77 | 0.0002 |
a
95% confidence interval (CI) estimates around mean LC50 estimates.
Chi‐square analysis of effects of the proc probit regression.
*
NA represents a probit mortality regression estimate without a 95% confidence interval (CI).