2.2.1.1. Spore counts

To determine the degree of infection of Nosema spp. in a sample it has been suggested that subjective judgement on an arbitrary infection scale can be used (Doull and Eckert, 1962; Gross and Ruttner, 1970). However, for research purposes, such estimations should not be employed if some degree of precision is required.

The easiest way to count Nosema spp. spores is to use a traditional haemocytometer as described in the miscellaneous methods paper of the BEEBOOK (Human et al., 2013) and Cantwell (1970).

Although yeast and Nosema spores reflect light differently in regular light microscopy, the use of phase contrast microscopy will avoid any misidentification (see section 2.2.2.1).