Honey bees not on brink of extinction
For about 15 years now, the story of alleged colony collapse disorder has persisted in the media, often attributed to pesticides and genetically modified plants. There is increasing evidence, however, that worldwide honey bee populations remain stable or are even growing. Although currently no evidence exists for the theory of colony collapse, it is also clear that bees are exposed to various risks. The greatest threat to honey bees is the Varroa mite. Pesticides, on the other hand, play a subordinate role in bee health.
Thursday, November 18, 2021
Environmental NGOs have been warning for years of a ‘bee-pocalypse’ – i.e. the extinction of honey bees – referring repeatedly to studies that claim to have found a connection between the use of neonicotinoids or the cultivation of genetically modified plants and a decline in bee populations. But these claims do not stand up to closer scrutiny. There is consensus among institutions such as the US Environmental Protection Agency (EPA), the United States Department of Agriculture (USDA), Health Canada and the Australian Pesticides and Veterinary Medicines Authority (APVMA) that bees are not currently in crisis and are not threatened with extinction due to the use of pesticides. The number of bee colonies is also increasing in Europe.
No risk to bee colonies from neonicotinoids
The results of 13 large-scale field studies within the last 10 years, in which the bee conditions were as close to reality as possible, in contrast to laboratory studies, paint a clear picture. The studies investigated the extent to which plants treated with neonicotinoids affect the health of honey bee or bumblebee colonies. No overall negative effects on the bee colonies were observed. Although it is true that individual bees may possibly be affected, the ability of hives to detoxify themselves and produce new offspring means this has no serious consequences for the colony as a whole. According to statistics from the Swiss Bee Health Service (Bienengesundheitsdienst BGD) run by apiservice, no changes in winter losses of bees have been observed in recent years.
Wide range of other dangers
Nevertheless, there are many dangers to bee health that should not be underestimated. The biggest threat to the honey bee is the Varroa mite, originally from Asia, which spread to Europe and the US during the second half of the 20th century. The mite attacks both larvae and adults, causing permanent weakness. Left untreated, infestation of a hive will lead to its destruction within one to three years. It is therefore the responsibility of beekeepers to ensure sufficient hygiene in the hives and, if necessary, to use suitable treatment against the pest. In addition to the Varroa mite, the intestinal fungus Nosema ceranae also poses a significant risk to bees. Infected bees are usually unable to fly, and crawl or hop around. Here again, prevention is better than cure. But caution is important – beekeeping requires time and expertise; for example, in handling the various biocides used to combat the Varroa mite. It is essential to prevent bee poisoning through misapplication, or residues in honey due to unauthorised biocides.
In addition to beekeepers, farmers are also responsible for careful application of plant protection products that may be toxic to bees, in accordance with the manufacturer's instructions. For example, products must be applied only at night when no bees are flying. The BGD's Annual Report 2020 revealed that all five cases of bee poisoning in 2020 could have been prevented by more careful use of biocides by beekeepers and pesticides by farmers.
Related articles
Using Crispr to combat climate change
In the Tages-Anzeiger newspaper, Nobel Prize winner Jennifer Doudna talks about the opportunities and risks of gene scissors. The tool can be used to specifically treat hereditary diseases, breed drought-tolerant plants and reduce greenhouse gas emis-sions from cows.
Anxious sweat as a cry for help
Plants live dangerously. They are surrounded by predators. But they are not completely at their mercy. Decades of research have shown this. For example, plants emit odours when attacked. This realisation could lead to new strategies for plant protection. However, it is still uncertain whether this will ever lead to a widely used product.
It pays to take a closer look
Pesticides are to blame for an increase in brain tumours in children in the Zürcher Weinland and the Bernese Seeland, according to a study carried out three years ago. Experts commissioned by the federal government have now come to a different conclusion: the results could also have been accidental.
Global events require adjustments
The Swiss want as much local food as possible on their plates. A desire that is becoming increasingly difficult to fulfil. Farmers are finding it increasingly difficult to protect their harvests. No wonder the level of self-sufficiency is falling.