4.2.2. Obtaining newly emerged workers for laboratory experiments without caging queens
Here is the most practical way to obtain newly emerged workers with relatively low chemical residue or pathogen exposure:
- Choose appropriate colonies from which to collect workers from based on health, environmental, genetic, and experimental design considerations discussed in sections 2 and 4.1.
- Select frames containing enough capped brood that will emerge in one to three days (i.e. pupae with dark eyes and cuticle) to ensure that the required number of adults can be obtained. Consult the BEEBOOK paper on miscellaneous methods by (Human et al., 2013) for information on how to obtain brood and adults of known age. Frames should be relatively new, not appear dark in colour or be soiled with faecal material or fungi, and should have few food stores.
- Remove all adult honey bees from the frame using a bee brush or by gently shaking the frame over the colony.
- Place the frame in an appropriate frame cage (see sections 5.2.1 and 5.3.1) that is outfitted with food (see section 7). Frame food stores and emerging honey bees can be segregated by cutting away honey and bee bread, or by installing 0.3-cm diameter aluminum hardware cloth screen around the stored food to keep workers from feeding.
- Transfer the frame cage to a laboratory incubator maintained at conditions discussed in section 6.
- Monitor the frame frequently to limit newly emerged worker exposure to the frame. Individuals should be removed from the brood frame at least every 12-24 hours to obtain age homogeneity; however, frequency of worker removal from the frame can be adjusted according to the needs of the study and to reduce contamination by pathogens and chemical residues.
- Gently brush newly emerged individuals into appropriate hoarding cages containing appropriate food (see sections 5 and 7). Newly emerged adults can also be removed gently from cells using a forceps before full emergence to further reduce potential for contamination. These individuals can be identified by small perforations in the wax capping of the brood cells. Care must be taken because the cuticle may not be fully hardened, and individuals can be easily damaged.
- Immediately place the hoarding cage containing newly emerged adults in a laboratory incubator maintained at conditions discussed in section 6.