Incidence of Nosema ceranae During Winter in Honey Bees Colonies Removed from Eucalyptus grandis plantations

Abstract

Nosemosis is a digestive disease of honey bees (Apis mellifera) caused by the microsporidia Nosema apis and N. ceranoe. In Uruguay only N. ceranae has been detected. The disease appears invariably in colonies that are moved to Eucalyptus grandis plantations at the end of the summer and causes important losses when colonies remain there during winter. The aims of this study were to determine how N. ceranae affects wintering of colonies that are removed from E. grandis plantations at the end of the Fall, and if proteic supplementation affects levels of infection. Two apiaries were installed in May in Salto and San José using colonies removed from an E. grondis plantation. Colonies received one of the following treatments: I) nosemosis controlling, 2) proteic supplementation, 3) nosemosis controlling and proteic supplementation, and 4) without nosemosis controlling and without proteic supplementation (control). In the Spring, colonies of the four groups in both apiaries presented no differentiation in their population and brood area. In San José apiary there were not differences in the nosemosis level between colonies with different treatments, while in Salto, colonies that have not received fumagilin and with proteic supplementation where more infected than the ones treated with antibiotic and without proteic supplementation. The present study shows that N. cerallae does not affect colonies during wintering and that proteic supplementation can increase infectation.