Ascosphaera apis
Ascosphaera apis is a species of fungus belonging to the family Ascosphaeraceae. It was one of the first entomopathogen genomes to be sequenced. It has a cosmopolitan distribution.
It causes the List of [diseases of the honey bee#Chalkbrood|chalkbrood] diseases in bees, which rarely kills infected colonies but can weaken them and lead to reduced honey yields and susceptibility to other pests and diseases.