What are the reasons for bee mortality and how can we counteract this problem?

Bees play a central role in the preservation of our ecosystem, culture, and agriculture. In search of food, the insects carry pollen from flower to flower, from which honey is later extracted; in the process, the bees pollinate about one-third of all agricultural crops and thus contribute significantly to the preservation of biodiversity. They ensure the spread of hundreds of thousands of plants on which countless animal species depend for their food. However, for years, a large number of the bee population is decreasing worldwide. In Europe, there are about 10% fewer bees than a few years ago, in the US there has been a decline of 30% – in the Middle East the figure is as high as 85% (NABU). In Germany, more than 60% of the approximately 560 wild bee species such as mason bees, trouser bees, sand bees, furrow bees, masked bees etc. as well as bumblebee species are threatened with extinction (Laves).

Bee mortality can have significant economic and environmental consequences, as nearly 80% of all crops and wild plants are pollinated by the western honeybee, with the remaining 20 percent pollinated by bumblebees, flies, solitary wild bees and other insects. If bees were to become completely extinct along with other pollinating insects, this would lead to a massive decline in crop yields worldwide. Without the pollination services of bees, people would have to dispense with a third of crops, and the decline in fruit and vegetables would be particularly severe. According to a UN body, between five and eight percent of global agricultural production depends on pollination, and its economic benefit in Germany is estimated at around 2.7 billion euros. Moreover, pollination of crops by bees not only increases yields but also improves the quality of the fruit (Schwartauer Werke). In July 2015, a group of researchers from Boston published a study on the potential consequences of a complete extinction of bees: global crop yields would fall by around 23 percent and the resulting malnutrition could lead to around 1.4 million additional deaths worldwide each year (derStandard). 

The reasons for bee mortality are diverse and are not yet fully grasped by science. Several factors seem to play a role and interact: 

Industrial agriculture with its pesticide use and monocultures is one of the main factors in bee mortality. In conventional agriculture, conventional fruit and vegetable production, and in many home and small gardens, insecticides are used to kill pests. However, these toxins also harm everyone else; systemic insecticides are particularly problematic because they spread to all parts of the plants, affecting even pollinators that collect pollen, nectar, or guttation droplets. The toxins of pesticides not only affect honey, but also influence the nervous system of insects and their natural ability to orient themselves and can impair their lifespan and reproduction. Moreover, in monotonous agricultural landscapes, insects cannot find flowering plants, i.e., food, shelter or nesting sites. Monotonous crops often only bloom for a short time, leaving bees starving for the rest of the year. All of this reduces the diversity of food available to bees.

bee mortality

This results in another cause, air pollution: insects absorb countless toxins from the air, water and plants, which are used in agriculture. In addition, there are pollutants from other sectors, such as exhaust fumes from traffic (NABU; Umweltinstitut München; Schwartauer Werke). 

Another cause is the elimination of habitats. In addition to the intensification of agriculture, the spread of residential, industrial and traffic areas is a decisive reason for the destruction of habitats for insects and plants. Across Europe, 320 hectares of natural or agricultural land are sealed every day (NABU; Umweltinstitut München; Schwartauer Werke). 

One of the most holistic causes is climate change. Among other things, global warming means that many flowering plants, such as dandelions, now bloom earlier than they did a few decades ago, upsetting the rhythms of insects and plants. Mild winter periods, sharp sudden changes in temperature and long periods of drought in spring and summer put additional stress on insects, deplete their energy reserves, make bees more susceptible to pests such as the Varroa mite and upset their entire cycle (NABU; Umweltinstitut München; Schwartauer Werke).

bee mortality

So, what to do about bee mortality? 

To prevent the extinction of honeybees, beekeepers must consistently control pests and ensure optimal care for their colonies. Farmers must follow bee protection regulations and apply pesticides that are classified as non-hazardous to bees. In addition, the cultivation of flowering areas is essential to create habitat and food supply for bees. Above all, further habitat destruction must be avoided. Not mowing roadsides during the flowering season, improving the supply of nutritive plants, sensibly reducing the use of pesticides and, if necessary, applying pesticides outside the bees’ flight periods can be helpful measures (Laves). But always preceding this is organic farming, which counteracts bee mortality by avoiding synthetic chemical pesticides, not growing in monocultures, and thus ensuring insect habitat through more frequent crop rotation and more natural ecosystems than on conventional farms (utopia). Private households can sow bee-friendly plants at their homes, paying attention to organic quality. Furthermore, the selection of honey from the region, if possible, also in organic quality, the renunciation of pesticides, the installation of an insect hotel, the thorough washing out of honey jars in the case of imported honey, since honey residues in the glass container can transmit diseases, can offer additional solutions to the problem (FINE).

aware_ member Porsche sets a good example and is committed to nature and species conservation at its Zuffenhausen site. Here, the company settles 13 bee colonies, each with around 50,000 honey bees, as well as wild bees, bumblebees and other insects, in a factory-owned naturally planted meadow orchard. Various fruit trees, hedges and flower strips provide a wide range of food for the insects. The initiators of the project are Porsche Catering and Environmental Management. The project is not the first of its kind: At the Leipzig plant, around three million honeybees have already been living on the 132-hectare natural off-road site since 2017 (Porsche).  

It remains to be said that agriculture must be made much more sustainable and end consumers must adapt their lifestyles and consumption habits in such a way that further bee mortality can be prevented. This can only succeed, and the protection and promotion of biodiversity can only be successful if all factors interact. 

by Marie Klimczak