The most prevalent viral pathogen of honeybees is Deformed Wing Virus (DWV) and its two most widely studied and common master-variants are DWV-A and DWV-B. The prevalence of DWV variants in the UK and in the US is changing, with the prevalence of the DWV-A strain declining and DWV-B increasing over time. In 2012, only DWV-A was detected on the Hawaiian Islands of Oahu. In this study we focused on a colony-level survey of DWV strains in a single apiary and examined the prevalence of DWV variants over the course of two years. In 2018 and 2019, a total of 16 colonies underwent viral testing in January, May, and September. Of those 16 colonies, four were monitored in both 2018 and 2019. Individual colonies showed variability of DWV master variants throughout the sampling period. DWV-A was consistently detected; however, the detection of DWV-B was variable across time in individual colonies. Ultimately, this study demonstrated a seasonal variation in both viral prevalence and load for DWV-B, providing a perspective on the dynamic nature of DWV master variants emerging in Hawaii.
Due to the ongoing global spread of the small hive beetle (SHB), Aethina tumida, there is a significant need for detection and practical management strategies against this pest. The standard inspection strategies for SHBs involve (1) detailed visual examination of the colony, which is challenging in areas with defensive bees, or (2) sampling beetles via traps, which requires repeated visits to the apiary and can be difficult for beekeepers with apiaries in rural areas. In this study, we modified the inspection sequence to examine the in-hive distribution of the beetle and assess whether a limited, yet targeted, inspection could provide valuable information on beetle infestation. We conducted our modified sampling in three different countries: Hawai’i (USA), Mexico, and Costa Rica. We found that targeted screening of the top areas of the hive (cover and top-side frames) provided reliable information about the relative prevalence of SHBs in a colony. The results also suggested that SHBs do not naturally congregate on a bare bottom board but migrate downward during inspection. Trap placement on the bottom floor of the hive may underestimate beetle presence in low to medium pest levels. The proposed inspection protocol is not influenced by the genetic origin of the bees (Africanized or European) and could be a practical alternative for assessing SHB infestation levels in honeybee colonies.
The distribution of the Africanized honey bee (AHB) in the Caribbean region is “patchy”, with some islands, such as Puerto Rico, testing positive for AHB since the mid 1990s, while other regions, including the Dominican Republic and Haiti appeared to be free of AHB. In this study we confirm, through molecular test of mitochondrial genetic material, that AHB is now present in managed colonies in the Dominican Republic. The presence of the Africanized mitotype was established using the cytochrome b/BglII assay. Results show that 39% of the colonies sampled displayed the African haplotype, and 73% apiaries had at least one Africanized colony. Six out of the eight provinces surveyed (excluding Santo Domingo and Dajabón) tested positive for the presence of AHB colonies. The results indicate that AHB is present in the Dominican Republic and that currently it may be more prevalent in the northwest region of the country. However, a more intensive survey is needed to confirm countrywide prevalence of the African genotype, and to examine the situation in neighboring Haiti.