7.8.5. Recommendations and considerations for oral exposure of a test substance to caged adult workers in the laboratory

Choice of whether to inoculate workers individually or as a group will mainly depend upon the particular experiment. Few investigations have compared results from individual versus group feeding of a test substance, although it is clear that both can be effective. For example, Tanner et al. (2012a) demonstrated no difference in individual versus group feeding of intra-host N. ceranae spore development 14 days post-inoculation. Research should also examine homogeneity of test substances, especially suspensions containing particles such as Nosema spores that may settle in liquid. In these cases, a test substance fed as a solid may ensure a more even distribution of particles.