Insect Pathology and Microbial Control
Honey-bee larvae are most susceptible to infection by ingested spores of Ascosphaera apis when they are 3-4 days old and are chilled briefly two days later, immediately after they are sealed in their cells to pupate. Spores of A. apis germinate in vitro best when nearly anaerobic but the mycelium is aerobic. Spores germinate in vivo in the larval gut, which is almost anaerobic. The mycelium survives in 3-4 day old larvae better than in younger ones probably be-cause of the shorter time it is deprived of oxygen. It invades tissues of chilled larvae because chilling probably allows oxygen to reach and activate it: in vitro the fungus grows faster at usual brood temperatures (30-35°) than when colder .
Bailey, L., "The Effect of Temperature on the Pathogenicity of the Fungus, Ascosphaera Apis, for Larvae of the Honey Bee, Apis Mellifera" (1966). An. Paper 233.
Available for download on Friday, January 01, 4500