Bees dying due to neonicotinoids?
by Michael Watson (comments: 0
It is no secret that the use of pesticides in agriculture contributes significantly to bee death. From herbicides for weed control, fungicides for fungal infections, and insecticides for pest control, modern agriculture has a chemical solution for every plant-related problem. Not all of these pesticides are harmless to the environment: In recent years, the use of neonicotinoids has been sharply criticized, as this group of substances poses a great risk to wild insects and wild and honeybees.
What are neonicotinoids?
Neonicotinoids have been used for years in pesticides for agriculture. This group of substances has proven to be highly effective against a variety of pests, such as aphids, leafhoppers, mealybug scales, or small moths. In Europe, neonicotinoid-based pesticides are also very popular among conventional farmers, who spend hundreds of millions of euros annually on this plant protection product.
Neonicotinoids are a type of systemic insecticide. This means that plants absorb the active ingredient through the leaves or roots and then distribute it throughout the entire plant. For pests, this is bad news, as no matter where they attack the plant, they absorb the toxic substance. Neonicotinoids are selective neurotoxins that bind to nerve cells and block the transmission of nerve signals. Insects that come into contact with neonicotinoids experience continuous stimulation in their nervous system, leading to spasms and ultimately death.
Use and application of neonicotinoids
When neonicotinoids came onto the market in the 1990s, they were initially sold as a gentle pesticide. Unlike previous pesticides, neonicotinoids were not sprayed, but applied directly to the seed - known as “dressing”. Proponents of neonicotinoids hoped that this would result in fewer harmful substances being released into the environment than with traditional spraying. As neonicotinoids spread from root to flower, they protect the plant from the day it is sown until it is harvested. However, when dressed seeds are sown, around 2 percent of neonicotinoids are released into the environment in the form of dust, where the neurotoxin is absorbed by other insects and animals.
Neonicotinoids are mainly used in the form of dressed seeds. They are particularly common in the cultivation of cotton, sugar beet, maize and rapeseed.
Risks for wild bees and honey bees
Although wild and honeybees are by no means classified as pests, the use of neonicotinoids poses a significant risk to bees. Since neonicotinoids spread throughout the plant, they are also present in pollen and nectar, where they are absorbed by bees. Furthermore, neonicotinoids can be washed out of the plant by rain and irrigation, where they can enter groundwater and be taken up by other (non-agricultural) plants.
When directly exposed to neonicotinoids, most bees die, but even the smallest amounts can have drastic effects: Studies have shown that even small quantities of neonicotinoids can disrupt brain processes in bees, severely impairing their navigation, communication, and pollen collection abilities. Many bees then fail to find their way back to the hive, and the entire colony suffers as a result. For years, scientists have been warning of the severe consequences of insect extinction: Without bees, our plants will no longer be pollinated. This could lead, in the worst-case scenario, to us having to pollinate our fields ourselves, or even to the inability to harvest any fruits, vegetables, or grains. In Germany, insect extinction has already taken hold, and there are regions where the insect population has decreased by 80 percent over the last 30 years.
Bans and legal situation of neonicotinoids
Since 2013, certain pesticides containing neonicotinoids, such as Clothianidin, Imidacloprid, and Thiamethoxam, have been heavily restricted in the European Union. Since then, these substances have no longer been allowed for use on certain crops like sunflowers, corn, and rapeseed in open fields. However, their use in greenhouses is still permitted in Europe. Bayer and Syngenta, manufacturers of neonicotinoid-containing pesticides, filed lawsuits against this ban, but in 2018, the European Court of Justice upheld the ban on open-field use. Environmental protection groups, however, argue that the EU-wide bans do not go far enough. Greenpeace, for example, is calling for an immediate ban of at least seven neonicotinoid products from BASF, Bayer, and Syngenta.