4.5. Grafting of larvae
- Prepare plates
- Apply diets into cups
- Pre-incubate plates and thermoblocks for temperature regulation during grafting
- Take combs to the lab and start grafting
- --> Section 5.8. Incubation
According to the chosen method, rearing plates or petri dishes have to be prepared in advance, because larvae are already grafted into the first day’s diet. Grafting is the collection of larvae from a comb in the same way as beekeepers graft larvae for queen breeding (see the BEEBOOK paper on queen rearing for a detailed explanation of grafting (Büchler et al., 2013). A grafting tool or a paintbrush and a binocular loupe are recommended. The first priority in grafting is not to injure larvae. If the first grafting try fails (i.e. one suspects that the larva is injured), another larva should be taken. Larvae lie on their side in the bottom of the comb cell. Consequently, they breathe from the spiracles located on the upper side of their body. Upside-down grafting (i.e. larvae flipped over during the grafting process) should be avoided, because larvae should remain in the same position in the queen cup as originally on the comb due to their use of the open spiracles. Grafting should not take longer than 20 minutes per 48 larvae and a warm (>20°C, place pre-incubated thermoblocks below rearing plates, see 5.9. Feeding of diets) and humid environment should be maintained throughout. While grafting from one comb, additional brood combs should be stored in an incubator at 34.5°C and more than 60 % RH.