Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses, having switched hosts from the eastern to western honey bees (Apis ceranatoApis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemiology. As the principal driver of the spread of deformed wing viruses (mainly DWV-A and DWV-B), varroa infestation has also driven global honey bee health declines. The more virulent DWV-B strain has been replacing the original DWV-A strain in many regions over the past two decades. Yet, how these viruses originated and spread remains poorly understood. Here, we use a phylogeographic analysis based on whole-genome data to reconstruct the origins and demography of DWV spread. We found that, rather than reemerging in western honey bees after varroa switched hosts, as suggested by previous work, DWV-A most likely originated in East Asia and spread in the mid-20th century. It also showed a massive population size expansion following the varroa host switch. By contrast, DWV-B was most likely acquired more recently from a source outside East Asia and appears absent from the original varroa host. These results highlight the dynamic nature of viral adaptation, whereby a vector’s host switch can give rise to competing and increasingly virulent disease pandemics. The evolutionary novelty and rapid global spread of these host–virus interactions, together with observed spillover into other species, illustrate how increasing globalization poses urgent threats to biodiversity and food security.

Beeswax is a natural product that is primarily produced by honey bees of the genus Apis. It has many uses in various kinds of industries, including pharmacy and medicine. This study investigated the effect of storage and floral origin on some physicochemical properties of four beeswax samples. The floral origin of the beeswax samples was determined microscopically and the investigated physical properties were the melting point, color, surface characteristics and thermal behavior. The studied chemical constituents were the acid value, ester value, saponification value and the ester/acid ratio. The FT-IR, SEM, EDX, XRD and TGF techniques were applied to meet the objectives of this study. The physical properties of the beeswax were affected by the storage period and floral origin. The melting point of the beeswax samples significantly increased with the increase in the storage time, from 61.5 ± 2.12 °C for the 3 month sample to 74.5 ± 3.54 °C for the 2 year stored sample (p-value = 0.027). The acid values of the 3 month, 6 month, 1 year and 2 years stored samples were 19.57 ± 0.95, 22.95 ± 1.91, 27 ± 1.91 and 34.42 ± 0.95 mgKOH/g, respectively. The increase in the acid value was significant (p-value = 0.002). The ester values of the studied beeswax samples significantly increased with the increase in storage time as follows: 46.57 ± 2.86 mgKOH/g for the 3 month stored sample, 66.14 ± 3.82 mgKOH/g for the 6 month stored sample, 89.77 ± 0.95 mgKOH/g for the one year stored sample and 97.19 ± 1.91 mgKOH/g for the 2 year stored sample (p-value ≤ 0.001). Similarly, the saponification value and the carbon percentages increased with the increase in storage time. Unlike the results of the chemical components, the oxygen percentage decreased with the increase in storage time as follows: 11.24% (3 month), 10.31% (6 month), 7.97% (one year) and 6.74% (two year). The storage and floral origin of beeswax significantly affected its physicochemical properties in a way that qualify it to act as a phase changing material in the thermal storage energy technology.