Table 4. Coumaphos and imidacloprid concentrations, in ppb, detected in honey and adult bees before start of treatment (16 July) and after 32 days (17 Aug.) in Mississippi with respect to treatment group.
| Material | Coumaphos conc. | Imidacloprid conc. | 16 July | 17 Aug. | ||
|---|---|---|---|---|---|---|
| Coumaphos | Imidacloprid | Coumaphos | Imidacloprid | |||
| Honey | 5.8 ppm | 20 ppb | Trace | - | 54.2 | 23.6 |
| 5.8 ppm | 5 ppb | - | - | 202 | 6.9 | |
| 5.8 ppm | None | - | - | 60 | 4.4 | |
| None | 100 ppb | - | - | Trace | 86.3 | |
| None | 20 ppb | - | - | - | 19 | |
| None | 5 ppb | - | - | - | 11.7 | |
| None | None | - | - | - | 2.3 | |
| Adult | 5.8 ppm | 20 ppb | Trace | - | 260 | 5.1 |
| bees | 5.8 ppm | 5 ppb | 11.3 | - | 104 | 2.5 |
| 5.8 ppm | None | - | - | 111 | 3.3 | |
| None | 100 ppb | - | - | - | 18.9 | |
| None | 20 ppb | - | - | - | 4.6 | |
| None | 5 ppb | - | - | - | 2.7 | |
| None | None | - | - | - | - | |
The limit of detection of imidacloprid was 1 ppb and that of coumaphos was 5 ppb; “Trace” indicates positive coumaphos detection but <5 ppb; dashes indicate none detected.