An outbreak of nosematosis in bees was detected in Russia

“In early March 2023, the Kemerovo testing laboratory of the FGBI “ARRIAH” received one sample of dead bees from a private owner for testing for the presence of amoebiasis, acarapidosis, varroatosis, nosematosis pathogens. According to the results of the study, the causative agent of nosematosis was found in the sample,” the ARRIAH press service said in a statement.

The experts explained that the degree of damage to bees by nosematosis is estimated in crosses: up to 10 spores – one cross, up to 100 – two, up to 1000 – three and over 1000 – four crosses. “The degree of damage to the test sample was three crosses,” the experts noted.

Nosematosis is an invasive disease of adult bees, queens and drones, which is accompanied by destruction of tissues in the midgut, indigestion, weakening and death of bee colonies.

The main route of infection is alimentary (penetration of spores from insect excrement into the intestines). The main symptom of the disease is fecal spots on the walls of the hive and frames.

Experts noticed that the parasite forms spores that remain viable for a long time, since they are covered on the outside with a resistant chitinous shell.

“The latent course of nosematosis, its non-specific external signs of damage to bees, is of particular importance. Therefore, it is difficult to make a diagnosis in a timely manner and start treatment,” ARRIAH experts noted.

They clarified that for research, samples of 50–100 live bees from a colony or fresh death from 10 to 20% of bee colonies in the apiary should be sent to the veterinary laboratory, a dead queen, as well as feces from bees, 5 g of honey, 0, 5 g of perga or pollen pollen, washings from foundation sheets. The dead queen bee is considered as a sample from the family.

Experts also noted that pets and humans are not infected with nosematosis, but can be carriers of the pathogen.