Carbon Dioxide Activation of Spores of the Chalkbrood FungusAscosphaera Apis

Chalkbrood disease in honey bees

“…Spores consumed by the honey bee larvae germinate in the lumen of the gut, probably activated by CO 2 (Heath and Gaze, 1987;Bailey and Ball, 1991). Infected larvae rapidly reduce food consumption, and then stop eating altogether.…”

Chalkbrood development in honeybee brood under controlled conditions

“…The gut content of each larva or pupa was inoculated onto a Petri dish (9 cm) containing MY20 medium (Takatori and Tanaka, 1982) and kept in a incubator under appropriate conditions for spore development (12% CO 2 , 30°C, 80% relative humidity) (Heath and Gaze, 1987 (Michener, 1974). Since spores of the fungus have been widely isolated from stored honey and pollen (Heath, 1982;Gilliam, 1986;Koenig et al, 1987a;Gilliam et al, 1988), larvae younger than fifth instar could be resistant, as was pointed out by Bailey (1967), because there was not enough time for most of the ingested spores to germinate and grow before being voided.…”

Influence of carbon dioxide on Nosema apis infection of honeybees (Apis mellifera)

“…In the experiment, exposure to carbon dioxide stimulated the spores to develop. Similar effects of CO 2 exposure, although applied at lower concentrations not exceeding 12.5% by volume of air, were found for spores of Ascosphaera apis, a fungus causing a dangerous disease in honeybees called chalk brood (Heath and Gaze, 1987). Possibly what stimulated the N. apis spores to develop were bicarbonate ions, as suggested by de Graaf et al (1993).…”