4.12. Assessing survival

Larvae can be classified as dead when respiration ends, when they lose body elasticity, or when they develop oedema and change colour to greyish or brownish (Genersch et al., 2005; 2006). Dead larvae should be removed from the incubator to prevent decomposition by bacterial or fungal saprophytes and subsequent contamination of other larvae; in pathology studies dead larvae need to be sampled anyway. Non-emerged individuals on day 22 after grafting are counted as dead during pupal stage. Live adults and dead adults that have left their cell and show a regular development are both counted upon emergence or at the latest at day 22.