Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Microsporidia detection (tool-kit) and control systems guidelines

Introduction of a nosema infection into bumble bee colonies and into rearing facilities can be accomplished primarily in four ways,
- By introducing queens caught in the wild for breeding purposes
- By returning colonies from pollination assignments to the rearing unit
- By feeding colonies material (primarily pollen) contaminated by N. bombi spores and by working hygienically.

A nosema infection has a negative impact on colony development and therefore on the pollination performance of infected colonies. Nosema infection also has a negative impact on the continued rearing of new queens if the rearing colonies are infected. No cure is known for nosema disease in infected colonies. Thus, the only solution to deal with infection if found within rearing facilities, is to destroy all infected colonies, to avoid new introductions of the parasite and to maintain high hygienic standards.

Nosema diagnosis on a regular basis is advisable. Simultaneously, other diseases and parasites can be checked for within colonies inspected for N. bombi. It is recommended to use random sampling of the rearing material every 4 week and diagnose for diseases and parasites. This check provides information of the health situation of the bees and developing infections or parasitation are detected before a general outbreak may occur. As discussed elsewhere, both microscopical and molecular techniques are available for dection of N. bombi.

The PCR method developed in the Pollinator Parasites project, to detect N. bombi infections in Bombus spp., by amplifying partial rRNA of N. bombi, provides considerable advantages over microscopic detection techniques, especially through an increased level of detection sensitivity. This is because there is a risk of overlooking a low concentration of spores by light microscopy. Moreover, molecular detection reduces the risk of misidentification of N. bombi with other parasites and with starch grains, and gives the ability to detect all developmental stages of the microsporidium. The PCR based detection method will be useful in providing a quick and reliable identification of N. bombi infections as well as representing a sensitive tool for epidemiological studies of this little known microsporidium.

Detailed protocols for using the tool-kit for N. bombi detection are available in the Technical report from Pollinator Parasites Professional meeting of bumble bee breeders, Wageningen, The Netherlands, December 2, 2005 and on the project web site.

Informations connexes

Reported by

Swedish Univ. Agric. Sci
Box 7044
750 07 Uppsala
See on map