Is Acarapis woodi a single species? A new PCR protocol to evaluate its prevalence.

Acarapisosis is a disease of the adult honey bee Apis mellifera L., caused by the tracheal mite Acarapis woodi (Rennie), that affects the prothoracic tracheas of worker honey bees. Although it is not usually considered a real problem for honey bee colonies in southern Europe (mainly Spain and Greece), where the majority of professional beekeepers are located in Europe, recent works have reported the constant presence of this mite in this area, making it a potential cofactor for colony losses. In this study, we developed a specific PCR diagnostic tool that improves the techniques used so far and allowed us to confirm the presence of this parasite in Spain, urging the need to monitor its prevalence and implications in the health of the colonies. Indeed, in a total of 635 apiaries analysed, the prevalence of A. woodi in 2010 was 8.3 and 4 % in 2011. The mite is present in bee colonies over time and should not be underestimated as a possible cofactor in the collapse of bee colonies. Additionally, some positive samples were cloned so a genetic analysis on the diversity within A. woodi isolates was also approached. This allowed us to identify different genetic variants within an isolate, even when they were present at low frequencies. And this genetic analysis revealed the existence of a different clade of Acarapis sequences that could represent a new species or subspecies, although more research is required to verify the identity of this novel lineage at genetic and morphological level.

Low prevalence of honeybee viruses in Spain during 2006 and 2007.

RNA viruses that affect honeybees have been involved in colony losses reported around the world. The aim of the present work was to evaluate the prevalence and distribution of honeybee viruses during 2006-2007 in Spanish professional apiaries, and their association with colony losses. Four hundred and fifty-six samples from apiaries located in different geographic regions of Spain were analyzed. Thirty-seven percent of the samples had viral presence. Most (80%) had one virus and 20% two different viruses. All the analyzed viruses, Deformed Wing Virus (DWV), Israeli Acute Paralysis Virus (IAPV), Black Queen Cell Virus (BQCV), Sacbrood Virus (SBV) and Kashmir Bee Virus (KBV) were detected, but detection rates were lower than expected. According to these results and considering the high prevalence of other honeybee pathogens in Spain, the role of viruses in colony losses in Spain may be discussed.