Naturopathy

Bee dying causes, spread and consequences

Bee dying causes, spread and consequences / Naturopathy

Bees are buzzing ever more rarely

Do you wonder if it's still on their flowerbeds this year? In the winter of 2016/2017, many thousand bee colonies died - in the small Saarland alone, up to 3000, that is 20% of the population. Dying has two reasons: a mite and pesticides.

contents

  • Bees are buzzing ever more rarely
  • The Varroa mite
  • The beekeeper becomes an exterminator
  • Decline of wild bees
  • Not only bees die
  • Addictive substance for bees
  • An insect trap
  • A topic for the EU
  • Exact proof from Poland
  • Complicit with antibiotics?
  • monocultures
  • Without bees no apples
  • Pesticides and parasites
  • bee pastures

The Varroa mite

The mortal enemy of bees is currently the Varroa mite. Originally she came from Asia and had adapted to the local bees. About 40 years ago, imported bees brought the parasites to Europe. The mite gets over the bee brood, sucks the blood of the larvae and transmits epidemics. She does not like cold or heat. The mild December 2016 was ideal for the plague.

The Varroa mite is responsible in this country for the destruction of thousands of bee colonies. (Image: emer / fotolia.com)

The beekeeper becomes an exterminator

Protection against the mite is possible, but requires professional training: In Switzerland, for example, beekeepers give Oxal every year in the late summer and early winter - like bees acid in bee colonies.

Decline of wild bees

Particularly wild are currently the stocks of wild bees back. Above all, they are poisoned by pesticides. They also lose their habitat and food crops. Almost half of several hundred wild bee species are on the Red List.

Loss of habitat and the loss of food crops are indirect causes of this decline - a direct killer are the neonicotinoids. These pesticides destroy the bee's brain processes and their communication, their navigation and their ability to collect pollen.

If the bees are damaged by these poisons, then they make fewer collecting flights and can hardly orient themselves. They take longer to reach the hive. Even tiny amounts of these neonicotinoids, which are far below the limits, put bees, bumblebees and other insects out of power, found out the Berlin neurobiologist Randolf Menzel.

A French study under the direction of Mickael Henry confirmed Menzel's conclusion: The scientists exposed rapeseed, which they had stained with neonicotinoids. It turned out that the death toll of the worker bees shot up.

However, the bee colonies can compensate for this: they then breed more female bees and fewer drones, whose job is only to fertilize the queen. However, this will eventually lead to a genetic impoverishment because fewer and fewer males can pass on their genes.

Not only bees die

Long-term studies by the British Center for Ecology and Hydrology in 2016 showed that 62 wild bee species were radically shrinking since neonicotinoids were approved in 2002. Wild bees that specialize in rapeseed treated with these pesticides suffered losses of 20%.

A California study shows that the same is true for butterflies. Since the poisons have been used there, the number of butterflies of various species has decreased dramatically.

Bumblebees form fewer queens due to the poisons, solitary bees do not build nests, and in the case of legwheels the mating ends.

Due to the influence of pesticides less queens develop in the bumblebees. (Image: D.Pietra / fotolia.com)

Addictive substance for bees

Bees do not avoid the poison, but prefer it. They even prefer sugar solutions containing these pesticides to pure sugar solutions.

That is why they absorb a disproportionate amount of pollutants. The reason for this is that neonicotinoids act in the nervous system of bees similar to nicotine in humans. In other words, the bees become addicted.

British researchers led by Geraldine Wright of Newcastle University therefore demand that the use of these pesticides must be controlled in order to protect the bees from harm.

An insect trap

The "neonis" have a half-life of 1000 days. The plants absorb only 5% of the toxins, the rest gets into the soil. In addition, these pesticides are water-soluble. They therefore spread with the rain.

Even flower strips on the edges of fields to protect the insects are poisoned. In some cases, pesticide levels are even higher than on crops.

A topic for the EU

The topic of neonicotinoids has meanwhile arrived at the responsible EU Commission. Since valid studies by EU internal scientists are available, a ban on the corresponding products from Bayer and Syngenta is possible. These would be the agents clothianidin, imidacloprid and thiamethoxam.

So far restrictions already apply, so the manufacturers must provide evidence that justifies the approval. If tighter rules now come into force, the corresponding neonicotinoids should only be used in greenhouses.
The Green MEP Martin Häusling says: "It is a milestone for beekeeping, if the EU Commission actually proposes a total ban on neonicotinoids."

The EU Commission is considering tightening the use of neonicotinoids. (Image: Dusan Kostic / fotolia.com)

Exact proof from Poland

Polish veterinarians have been able to prove which of the pesticides and bee treatment agents cause bee mortality. Bee poisoning was caused mainly by chlorpyifos, dimethoate and clothianidin.

Complicit with antibiotics?

But it is probably not just the pesticides alone that cause bee mortality in recent years. American scientists found that the antibiotic tetracycline also scavenges the bees.

Nancy Moran of the University of Austin, Texas, believes that this drug apparently kills beneficial gut bacteria that protect insects from the harmful Serratia bacteria. Because the number of Serratia bacteria was increased in the bees, which were treated with the antibiotic. Beekeepers use tetracyclines to protect the bee larvae from American foulbrood.

An explanation for the dying of bees in Germany is the means but not, because in this country the use of antibiotics in beekeeping is prohibited.

monocultures

The insects are also threatened by monocultures. The situation is best still in the cities, where allotments, balconies and parks offer a variety. Corn, on the other hand, is as nutritious to the bee as the surface of the moon.

Without bees no apples

In 1990 there were still about 1.2 million bee colonies in Germany - today there are 650,000. The wild bees also look grim: around half are threatened or disappeared. The extinction of bees has fatal consequences for humans, because 80% of all plants are pollinated by bees. No apples without bee.

A variety of plants rely on the pollination of flowers by bees. If these fail, serious consequences threaten. (Image: Top Photo Group / fotolia.com)

Pesticides and parasites

A study by the University of Vienna recognized secondary infections, viruses, bacteria and parasites as responsible for a large part of the deaths, for example a virus that causes a deformation of the wings.

But the pesticides are not innocent of that. The immune system of the bees is permanently weakened by the plant toxins. The pathogens spread from bee to bee, without sufficient immune protection to fall ill and die
animals.

In Austria, for example, 95% of the applied poisons go into the soil, and especially these pesticides have reduced the total stock of insects by 80% in ten years. Instead of 58 wild bee species, there are 14.

bee pastures

If you have a small garden, you can help the bees and create a bee pasture. Linen, clover, bee lover, borage, cosmea, dyer's dog chamomile and buckwheat are particularly suitable for this. So there's always something blooming from spring to fall. Early bloomers such as liverwort or deadnettle help the insects before the fruit trees bloom.

Flowering shrubs are also perfect as a bee pasture, and they nourish not only bees, but also other insects and birds. Birds also offer nesting sites. Native plants for such a bee paradise are for example wild roses, elderberry, hawthorn, blackthorn, pear, rowan, quince, cornell cherry, sea buckthorn or goji berry. After flowering birds eat the valuable fruits. (Dr. Utz Anhalt)

Polish study:
Tomasz Kiljanek et al. Multi-residue method for the determination of pesticides and pesticide metabolites in honeybees by liquid and gas chromatography coupled with tandem mass spectrometry-Honeybee poisoning incidents, Journal of Chromatography A (2016). DOI: 10.1016 / j.chroma.2016.