Ascosphaera apis

Environmental effects on fungal infections in honeybee larvae Apis mellifera (Hymenoptera: Apidae)

Among the social insects, honeybees Apis mellifera have an exceptionally diverse set of parasites and pathogens. In this study two species of fungal diseases have been investigated: one is the common brood diseases, chalkbrood (Ascosphaera apis) and another opportunistic, but less common pathogen in honeybees, the stonebrood (Aspergillus flavus). Using the honeybee larvae as host and these two pathogens we investigated in vitro temperature impacts on the infected larvae. Temperature is known to have a crucial role in mediating the outcome of the host – parasite interactions; however there is limited information on the possible competition among fungal pathogens within the honeybee host. In addition, we investigated within-host competition among different fungal pathogens within a single larva and the role temperature plays in mediating these interactions.

The abstract shown here should not be considered to be a publication and should not be cited in print without the author's permission.

Asexual reproduction in the honey bee fungal pathogen Ascosphaera apis

Ascosphaera apis is an important fungal pathogen of honey bees. A. apis produces sexual spores (ascospores) that are the primary infective agent of chalkbrood disease. Honey bee larvae can be infected with A. apis by ingesting larval food contaminated with ascospores. By contrast, asexual reproduction has never been described in A. apis, although it is a widespread form of propagation in Ascomycetes. Since asexual reproduction does not require mating, it allows rapid production of large numbers of conidia (mitospores), and their subsequent dispersal into new areas. This study thus fills an important gap in current understanding of the developmental cycle of an important fungal honey bee pathogen. Herein we describe asexual reproduction in A. apis and discuss its potential role in host pathogenesis and in the dissemination of this infectious bee disease in the environment. Considering the worldwide spread of chalkbrood disease and the lack of EPA approved drugs to cure it, an understanding of the A. apis life cycle is an important factor in the design of a disease management program.

The abstract shown here should not be considered to be a publication and should not be cited in print without the author's permission.Syndicate content