5.2.1. Minimum criteria for frame and hoarding cages in which to maintain adult workers in the laboratory
- Generally, frame and hoarding cages of all types should meet the following minimum criteria; however, discretion may be used depending on the purpose of containing honey bees (e.g. for caging newly-emerged adults in a brood frame or for performing experiments using hoarding cages).
- Cages should be used once and discarded, or sterilised and cleaned if used multiple times, to minimise contamination by pathogens and chemical residues.
- Single-use cages are recommended for studies involving pesticide toxicology because of the difficulty in removing chemical residues.
- Multiple-use cages can be used for honey-bee pathogen studies and should be made from materials that are easily sterilised (e.g. autoclaved or irradiated), such as stainless steel and glass. Type of sterilisation required will depend on the nature of the study. For example, exposure to 121°C for 30 minutes will destroy N. ceranae spores (Fenoy et al., 2009). Metal and plastic cages can be further decontaminated using acetone*:
1. Wash cages using a standard laboratory dish washer
2. Apply a sparse quantity of technical grade 100 % acetone (the preferred solvent in toxicology laboratories) to a cloth and wipe cage clean. Attention should be paid to effects of acetone on plastic cages.
3. Soak a new cloth in warm soapy water and wash/rinse cage.
4. Rinse cage with water.
5. Dry cage using a new cloth, and air-dry until all liquid evaporates .
*Refer to your own laboratory safety manual to learn how to properly work with acetone.
- Materials used to make cages should be inexpensive, and easily accessible and manipulated. Plastic and wood allow for easy modification of cages when, for example, an additional feeding device is needed.
- Cages should have a sufficient quantity of air holes to provide ventilation.
- To reduce risk of contamination by pathogens and chemical residues among cages maintained in the same incubator, ventilation holes should be covered by filter paper or similar breathable material. If vents are unfiltered, cages should face in opposite directions and should be placed sufficiently far apart to prevent inter-cage trophallaxis or frass movement.
- Cages should allow both living and dead honey bees to be easily removed during the experiment, and should prevent live bees from accidentally escaping.
- At least a portion of the cage should be transparent to allow honey bees to be observed.
- Cage size will depend on the number of honey bees to be detained. For example, 500 cm3 (i.e. 500 ml) can easily accommodate several hundred workers, whereas cages of 100 cm3 are suitable for maintaining 30 workers. Generally, a ratio of ~3:1 (cm3/bee) is appropriate for maintaining less than a few hundred workers.