Stonebrood is a fungal disease caused by Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger. It causes mummification of the brood of a honey bee colony. The fungi are common soil inhabitants and are also pathogenic to other insects, birds and mammals. The disease is difficult to identify in the early stages of infection. The spores of the different species have different colours and can also cause respiratory damage to humans and other animals. When a bee larva takes in spores they may hatch in the gut, growing rapidly to form a collarlike ring near the head. After death the larvae turn black and become difficult to crush, hence the name stonebrood. Eventually the fungus erupts from the integument of the larva and forms a false skin. In this stage the larvae are covered with powdery fungal spores. Worker bees clean out the infected brood and the hive may recover depending on factors such as the strength of the colony, the level of infection, and hygienic habits of the strain of bees there is variation in the trait among different subspecies/races. Stone Brood is a Disease that takes over bees in the Honey Comb by eating them and takes the over the food storage that the worker bees make.
Stonebrood is not regarded as a serious disease in normal circumstances, its effects on the colony being only slight. It is generally present in the majority of colonies at some point in time and can be present in its spore stage without affecting the colony. However, colonies that are already weakened by other circumstances may suffer to a greater extent and especially in early spring.