The use of antibiotics is not permitted in Switzerland; moreover, no other medication exists to combat European foul brood. Hives with symptoms must therefore be destroyed in order to limit the outbreak, and the contaminated material must be sanitised. Since prevention is the best cure, early detection is desirable. Numerous studies have been undertaken and documents have been created at the Swiss Bee Research Centre and elsewhere to draw the attention of beekeepers to these problems and inform them about the causes and the control measures to be implemented.
Holland J. M., Sutter L., Albrecht M., Jeanneret P., Pfister S. C., Schirmel J., Entling M. H., Kaasik R., Kovacs G., Veromann E., Bartual A. M., Marini S., Moonen A.-C., Szalai M., Helsen H., Winkler K., Lof M. E., van der Werf W., McHugh N. M., Smith B. M., Wallis D. W., Cresswell J. E.
Moderate pollination limitation in some entomophilous crops of Europe.
Pollination services to crops may be worsening because of declines in farmland pollinators, but the consequences for yields have been uncertain. We therefore investigated pollination limitation in four entomophilous crops (oilseed rape, sunflower, pears and pumpkin) by quantifying the difference in harvestable mass between openpollinated and saturation-pollinated (hand-pollinated) flowers. We also examined whether pollination limitation in the four crops was associated with the number of flower visits by insects. Across 105 commercial fields in six European countries, the average decrease in harvestable mass due to pollination limitation was 2.8 % (SE=1.15). Among crops, the highest decreases were in sunflowers (8%) and in one of three oilseed rape production regions (6%). We observed substantial variation among crops in the numbers of insect visits received by flowers, but it did not significantly correspond with the levels of pollination limitation. Our results suggest that yields in these crops were not severely pollination-limited in the regions studied and that other factors besides visitation by pollinators influenced the degree of pollination limitation.
