Table 1.
Specifications of the tested treatment methods with acronym, LiCl concentration used, treatment period, number of tested colonies, and intervals of data collection for the preliminary and main experiments
| Treatment method | LiCl concentration | Treatment period [days] | No. of colonies | Start of brood assessment | Sampling interval of bees and food | |
|---|---|---|---|---|---|---|
| Preliminary experiment | ||||||
| Positive control: | 250 ml formic acid; Nassenheider® | – | 8 | 4 | – | – |
| P1: | 7 l syrup; 1 day after ROQ* | 25 mM | 8 | 4 | – | – |
| P2: | 4.5 kg candy; 1 day after ROQ* | 50 mM | 8 | 5 | – | – |
| Experiment I, 2021 | ||||||
| Positive control: | 250 ml formic acid; Nassenheider® | - | 9 | 9 | – | – |
| A1: | 2.5 kg candy; on the day of ROQ* | 50 mM | 9 | 6 | 5 days after application | 4 days |
| Experiment II, 2022 | ||||||
| A2: | 2 kg candy; on the day of ROQ* | 50 mM | 5 | 10 | 3 + 19 days after application | 2 days |
| A3: | 4 × 0.5 kg candy in 7 day intervals; breeding colonies | 50 mM | 4 × 2 | 10 | 0 + 16 days after 1st application | 2 days |
*ROQ release of queen