Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Characteristics of the diets used for the two assays and the corresponding number of treated colonies
| Diet | Raw material consistency | Final consistency | Sugar syrup (%) | N° of colonies |
|---|---|---|---|---|
| First assay | ||||
| Pollen paste | Pellets | Paste | 23 | 16 |
| Pollen pellets | Pellets | Pellets | 0 | 8 |
| Feedbee® powder | Powder | Paste | 33 | 17 |
| Feedbee® paste | Paste | Paste | 0 | 10 |
| Candipolline® | Paste | Paste | 0 | 9 |
| Bee Food® | Paste | Paste | 0 | 9 |
| Karya Ari Keki® | Paste | Paste | 0 | 9 |
| Chestnut flour | Powder | Paste | 45 | 7 |
| Brewer's yeast | Powder | Paste | 43 | 8 |
| Nutri-Bombus® A | Paste | Paste | 0 | 11 |
| Nutri-Bombus® B | Paste | Paste | 0 | 11 |
| Nutri-Bombus® C | Paste | Paste | 0 | 10 |
| Total | 125 | |||
| Second assay | ||||
| Pollen paste | Pellets | Paste | 18.5 | 10 |
| 25% Feedbee® + 75% Pollen paste | Paste | Paste | 13.9 | 9 |
| 50% Feedbee® + 50% Pollen paste | Paste | Paste | 9.3 | 9 |
| Total | 28 | |||
Number of dead larvae, dead adults and produced gynes, and pre-switch and pre-gyne point period in colonies fed with pure pollen paste and pollen paste mixed with 25% and 50% Feedbee®
| Diet | Dead larvae | Dead adults | Number of produced gynes | Pre-gyne point period | Pre-switch point period |
|---|---|---|---|---|---|
| Pollen paste | 4 ± 1 | 1 ± 0.2 b | 134 ± 23 | 51 ± 3 | 56 ± 3 |
| 25% Feedbee® + 75% Pollen paste | 4 ± 2 | 2 ± 0.4 ab | 157 ± 17 | 52 ± 3 | 47 ± 4 |
| 50% Feedbee® + 50% Pollen paste | 5 ± 2 | 3 ± 1 a | 109 ± 18 | 51 ± 1 | 56 ± 3 |
Effects of different pollen substitutes on number of dead larvae within 24 days, number of dead adults within 24 days, colony duration, and number of emerged workers of artificially reared bumble bees
| Pollen substitute | Colony duration (days) | Dead adults (n) | Dead larvae (n) | Emerged workers (n) |
|---|---|---|---|---|
| Candipolline® | 80 ± 3 ab | 12 ± 2 ab | 18 ± 3 b | 2 ± 1 b |
| Bee Food® | 70 ± 1 bc | 23 ± 4 a | 32 ± 5 b | 13 ± 4 ab |
| Feedbee® powder | 89 ± 3 a | 8 ± 2 bcd | 30 ± 4 b | 11 ± 3 ab |
| Karya Ari Keky® | 70 ± 1 bc | 25 ± 4 a | 25 ± 4 b | 8 ± 3 ab |
| Brewers’ yeast | 81 ± 6 ab | 4 ± 1 cd | 23 ± 4 b | 7 ± 2 ab |
| Chestnut flour | 59 ± 2 c | 8 ± 2 bcd | 19 ± 4 b | 4 ± 1 ab |
| Feedbee® paste | 70 ± 2 bc | 10 ± 2 bc | 60 ± 4 a | 8 ± 3 ab |
| Nutri-Bombus® A | 75 ± 5 abc | 3 ± 1 d | 35 ± 7 ab | 12 ± 4 ab |
| Nutri-Bombus® B | 86 ± 4 ab | 3 ± 1 d | 34 ± 5 b | 17 ± 6 a |
| Nutri-Bombus® C | 79 ± 6 ab | 3 ± 1 d | 40 ± 8 ab | 7 ± 3 ab |