Abstract:

The presence of Varroa destructor in colonies of Apis mellifera is explained by the interaction among a number of factors including beekeeping practices and surrounding environment features. The aim of this study was to evaluate the relative impact of environment geographical region and beekeeping management on Varroa infestation levels throughout a year. A monitoring study was carried out during 2015 in north-central regions from Argentina, consisting of three sampling dates: 1) autumn survey before autumn acaricide treatment; 2) autumn survey after autumn acaricide treatment and 3) spring survey. During these visits, we collected samples for Varroa mites and Nosema sp. presence assessment and information concerning the apiary management practices during each period. Both regional location and beekeeping practices impact on V. destructor infestation level during the course of the year, but relative importance depend partially on the time of year when this was observed. Varroa infestation level is driven simultaneously by a wide-range of environmental factors (regional effect) and honeybee population dynamics. Additionally, colony life histories are also strongly affected by the management practices employed by beekeepers, especially regarding the Varroa mites control and the supplementary feeding. Complexity involving multiple factors interaction in socio-ecological systems like beekeeping is discussed.

EEA Rafaela

Author affiliation: Giacobino, Agostina. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Pacini, Adriana Cecilia. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Molineri, Ana Ines. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Rodriguez, Graciela Adriana. INTA. Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.

Author affiliation: Crisanti, Paola Andrea. INTA. Estación Experimental Agropecuaria Hilario Ascasubi; Argentina

Author affiliation: Bulacio Cagnolo, Natalia Veronica. INTA. Estación Experimental Agropecuaria Rafaela; Argentina

Author affiliation: Merke, Julieta. INTA. Estación Experimental Agropecuaria Rafaela; Argentina

Author affiliation: Orellano, Emanuel. INTA. Estación Experimental Agropecuaria Rafaela; Argentina

Author affiliation: Bertozzi, Ezequiel. INTA. Estación Experimental Agropecuaria Rafaela; Argentina

Author affiliation: Pietronave, Hernan Pablo. INTA. Estación Experimental Agropecuaria Rafaela; Argentina

Author affiliation: Signorini, Marcelo. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Abstract:

Honey bee colonies are threatened by multiple factors including complex interactions between environmental and diseases such as parasitic mites and viruses. We compared the presence of honeybee-pathogenic viruses and Varroa infestation rate in four apiaries: commercial colonies that received treatment against Varroa and non-treated colonies that did not received any treatment for the last 4 years located in temperate and subtropical climate. In addition, we evaluated the effect of climate and Varroa treatment on deformed wing virus (DWV) amounts. In both climates, DWV was the most prevalent virus, being the only present virus in subtropical colonies. Moreover, colonies from subtropical climate also showed reduced DWV amounts and lower Varroa infestation rates than colonies from temperate climate. Nevertheless, non-treated colonies in both climate conditions are able to survive several years. Environment appears as a key factor interacting with local bee populations and influencing colony survival beyond Varroa and virus presence.

Author affiliation: Giacobino, Agostina. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Molineri, Ana Ines. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Fondevila, Norberto Antonio. INTA. Instituto de Virología; Argentina

Author affiliation: Pietronave, Hernan Pablo. INTA. Estación Experimental Agropecuaria Rafaela; Argentina

Author affiliation: Rodriguez, Graciela Adriana. INTA. Estación Experimental Agropecuaria Hilario Ascasubi; Argentina

Author affiliation: Palacio, Marí­a Alejandra. INTA. Estación Experimental Agropecuaria Balcarce; Argentina

Author affiliation: Bulacio Cagnolo, Natalia Veronica. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Orellano, Emanuel. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Salto, Cesar Eduardo. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Signorini, Marcelo. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Merke, Julieta. INTA. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina