Epidemiological Survey of Ascosphaera apis in Small-Scale Migratory Apis mellifera iberiensis Colonies

Abstract

Honey bee hives are moved yearly mainly for pollination, but also to take advantage of consecutive flowering events to get as many harvests of honey as possible and/or to find favorable sites for food sources and summer temperatures. Such movements may lead to pathogen spill-over with consequences on the honey bee health and finally on population decline. Ascosphaera apis is the causative agent of the chalkbrood disease, a pathology affecting honey bee larvae that significantly harms population growth and colony productivity. In this study, we detected the presence of A. apis in adult worker honey bees by PCR-amplification of the intergenic transcribed spacer (ITS1) of the ribosomal gene (rDNA). We first optimized the DNA extraction by testing different protocols in individual and pooled (colony level) adult honey bee samples. Subsequently, the presence of the fungus A. apis was assessed in both stationary and migratory colonies (subjected to small scale regional level movements) to determine the effect of migratory practices on the dispersal of this pathogen. Results confirmed a higher prevalence of A. apis in migratory apiaries when compared to stationary ones, indicating that migratory colonies are more likely to develop chalkbrood disease. Given these results, we suggest that beekeepers should be aware of the risks of pathogens spreading while moving beehives, even within a reduced geographic range.

The Effect of Migratory Beekeeping on the Infestation Rate of Parasites in Honey Bee (Apis mellifera) Colonies and on Their Genetic Variability

“…This study provides further insights into the impact of migratory beekeeping practices on honey bee health [ 35 , 36 ] and on the infestation rate of pathogens and diseases in the colonies [ 39 , 40 , 68 ]. Our major finding is that migratory beekeeping and its associated stress lead to higher V. destructor and N. ceranae infestation rates in the colonies, which partially confirms our initial hypothesis.…”

“…Honey bee confinement, vibration and noise, and marked changes in colony temperature are among the negative influences on colonies associated with such practices. Moreover, the installation of colonies in new pollination locations might increase their exposure to pesticides [ 34 , 36 , 38 ] and pathogens [ 39 , 40 ]. These colonies must also adapt to new environmental conditions and potential stressors, including orientation cues, daily oscillations in temperature, humidity, and wind regimes.…”

Kuzey Marmara Bölgesindeki Bal ve Arılardaki Patojenlerin Tespiti ve Moleküler İncelenmesi

“…The most important fungal infection in honey bees is defined as Ascosphaeriosis (Chalkbrood Disease) [40] . It is reported that chalkbrood disease is very common in the world and in our country and seriously damages the production of bee products [41] . Although the findings obtained from our study are lower than the rates stated by Soysal and Gürcan [42] , it has been observed that the agent has continued its existence in the region for at least 9 years and threatened hive and bee health.…”

Detection and characterization of Deformed wing virus (DWV) in apiaries with stationary and migratory management in the province of Entre Ríos, Argentina

“…The movement to new pollination locations forces the colonies to adapt to new environmental conditions, including daily oscillations in temperature, humidity, and wind patterns. Additionally, their exposure to pathogen might increase, and infections by new pathogens may occur 39,40 . In fact, transportation and pollination services have recently been proposed to increase the infestation rate and abundance of Nosema ceranae and some viruses [27][28][29][30][31]37 in A. mellifera worker bees.…”