TABLE 1.
Imidacloprid median lethal dose (LD50) estimates for second‐instar Leptinotarsa decemlineata larvae from populations collected in Maine, Wisconsin, Oregon, and a laboratory, susceptible colony
| Site | Year | n | Dose (ng) | 95% CI a | χ2 b | P‐value | RR |
|---|---|---|---|---|---|---|---|
| Laboratory Colony | 2019 | 288 | 1.04 | 0.5–1.5 | 20.28 | <0.0001 | 1.00 |
| Oregon (Umatilla) c | 2019 | 192 | 0.7 | 0.4–1.1 | 43.64 | <0.0001 | 0.67 |
| Wisconsin (Dane) d | 2019 | 192 | 2.26 | 1.04–4.44 | 42.93 | <0.0001 | 2.17 |
| Wisconsin (Hancock) c | 2019 | 192 | 15.1 | 8.65–25.67 | 36.95 | <0.0001 | 14.52 |
| Maine (Aroostook‐1) d | 2019 | 96 | 1.42 | 0.5–3.43 | 23.41 | <0.0001 | 1.37 |
| Maine (Aroostook‐2) c | 2019 | 96 | 11.5 | 3.8–24.38 | 12.9 | 0.0003 | 11.06 |
RR resistant ration calculated using the Lab Colony as a reference.
a
95% confidence interval (CI) estimates around LD50 estimates.
b
Chi‐square analysis effects of the Proc Probit regression.
c
Conventional standard pesticide input population.
d
Organic standard pesticide input population.