## 4 Discussion
Only the option \"treating swarms (no brood) just after harvest\" had notable differences, assuming a higher relevance among beekeepers in Europe (scored 1.68) than in the Americas (scored 1.32). This could reflect the higher use of oxalic acid in Europe (very effective on swarms that are broodless) [38] rather than in the Americas. \"Monitoring the efficacy of treatments\" and \"Treating simultaneously all the colonies of the apiary\" were the most accepted practices, respectively, for American and European beekeepers. \"Maintaining the number of varroa mites below the harmful threshold\" in each colony was considered the high relevance practice both for American and European beekeepers. \"Monitoring varroa infestation during the active season\" was a common practice noted in several studies [21; 25; 39; 40]; we find that respondent beekeepers in each of the continents appear aware of the importance of monitoring and \"adopting diagnostic tools for measuring varroa infestation levels\" (e.g., powder sugar, alcohol wash, soap water, etc.). Concerning the use of acaricides for varroa control, it was well known that the application of veterinary medicines in the \"absence of brood\" increases the acaricide efficacy for active ingredients that act only on the foretic phase of varroa. In this survey, the majority of the respondent beekeepers (about 80% in each continent) indicated that they have treated colonies against varroa mites in the last two years, and almost half of the beekeepers used more than one active ingredient (49.7% in the Americas vs. 45.2% in Europe). Indeed, rotating the acaricidal products helps avoid long-term varroa resistance, something the respondents in both regions may indeed recognize [41], even if higher attention seemed provided by the American (71.4%) rather than the European beekeepers (52.6%). In detail, the results showed that among all the active ingredients used by the respondents to treat varroa, more than half of the beekeepers in the Americas and in Europe used mainly soft acaricides alone. Concerning the risk to develop AMR, this seems quite high; 31.6% of the beekeepers in Europe and 26.5% in the Americas treat with only one active ingredient against varroa. The common use of low-environmental-impact products (the \"Soft\" acaricides used, 55.1% in the Americas and 53.1% in Europe) was ascribed to oxalic acid, thymol, and formic acid in each of the continents. Similar results were observed by other surveys [21; 31]. The beekeepers in the Americas are much more likely to use formic acid compared to their European counterparts (46.9 vs. 27.2%), while Europeans were much more likely to use oxalic acid than those in the Americas (53.9 vs. 39.5%). The highest percentage of the use of oxalic acid in Europe [42] is not surprising, given that this active ingredient has been in use for a longer time. The most commonly reported treatment used by beekeepers in the Americas was formic acid (46.9%). [PERSON] et al. (2021) [31] highlighted the common use of organic acids (formic acid, oxalic acid, and lactic acid) and, at the same time, a reliance on the application of biomechanical methods as well as drone brood removal [21], something not considered in this survey. In Europe, [PERSON] et al. (2022) [21] found that commonly used acaricides included amitraz, thymol, oxalic acid, and formic acid, considering three distinctive clusters of countries in terms of varroa control (given our sample size, this was not possible in our study). Even if our study did not consider the different ways of the application of the veterinary medicines, our findings regarding the common use of oxalic acid in Europe (53.9%) appeared in accordance with this study (69.0% of 28,409 respondents). A very low percentage of American beekeepers (8.8%) used hop acid [43], while in Europe, none of the beekeepers who participated in the survey had ever used veterinary medicines containing this type of active ingredient.