Conference in 10th Annual Meeting Epizone "Going Viral"

September 28^th, 2016

Barroso-Arevalo S., Vicente-Rubiano M., Ruiz-Martinez JA., Goyache J. and Sanchez-Vizcaino JM.

Colony losses of western honey bee Apis mellifera have increased alarmingly in recent years. Viral infections, worldwide introduction of the ectoparasite mite Varroa destructor, nutritional deficiencies and environmental conditions are some factors involved in these losses [1]. Despite viruses are usually present in colonies without causing overt symptoms yet can cause colony losses under stressful circumstances. The role and importance of each factor as cause of colony stress is still under study, however the lack of nutritional resources may be one of the main threats considering the characteristics of beekeeping. In this study we examined whether the availability of nutritional resources based on landscape characteristics of apiaries, as botanic biodiversity, may influence honey bee health status, measured as the presence of weak colonies and disease symptoms and also by health indicators. The study was carried out in several apiaries located in natural environments of Tenerife Island (Canary Islands, Spain). Colonies were sampled in late-summer in order to evaluate colony strength and health indicators: presence and load of Varroa mite and deformed wing virus (DWV), black cell virus (BQCV), Israeli acute paralysis virus (IAPV) and sacbrood bee virus (SBV). Colony strength and Varroa load was measured following standard methods from the BeeBook to count for honey bees and mites, whereas viruses were studied using quantitative RT-PCR and colonies were classified attending to their viral load. Colonies were classified as “weak” when they showed symptoms or poor population while the rest of them were categorized as “healthy”, considering the beekeeping management and the season of the year. Landscape of each apiary was studied through a spatial analysis using CORINE Land Cover database and ArcGIS mapping [3]. DWV and BQCV were detected throughout the study, with high prevalence in both cases but medium and low load, respectively. Varroa was also detected in 90% of colonies and IAPV and SBV were not detected in any colonies. DWV load was correlated with Varroa infestation percentage (Spearman correlation test, p>0.05) and both were related to the colony strength (binomial logistic regression, p<0.05). Weak colonies were located in landscapes with less area occupied with wild plants or crops suitable for bee nutrition [4]. This result suggests a crucial role of the landscape characteristics in the survival of colonies. Our results show the importance of evaluating DWV and Varroa in productive apiaries as predictors of colony losses. In addition, we show the need of assessing adequate locations to ensure nutritional resources for honey bees. For this reason, future studies of apiaries maintained in natural environments should take location analysis and into account, in order to improve the availability of resources

	Servicio de Inmunología Viral y Medicina Preventiva (SUAT). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Universidad de Córdoba (UCO).
	Apoidea.