Butterflies and bees dying out throughout Europe. Scientists successfully tested a method to save them
The fact that insects, including bees and butterflies, are dying out is one of the most severe problems of environmental protection in Europe. German scientists have discovered that 75 percent of all insects have died out in Central Europe in the last 25 years.*
It is not only the fact that the numbers of butterflies, beetles and other kinds of insects have decreased dramatically. It is also the pace at which this is happening. According to findings by scientists, insects are disappearing eight times faster than mammals, birds and reptiles. The total volume of insects is decreasing by 2.5 percent every year. And the situation is no better in the Czech Republic. “For example, 19 butterfly species have died out in the past 60 years, half of the remaining 142 species is endangered,” pointed out entomologist Lukas Cizek from the Biology Centre of the Czech Academy of Sciences. The cause is the impoverishment of the landscape and overuse of chemicals in agriculture.
A solution that prevents the fast decrease of insects was tested in the former military area of Milovice, located near Prague. Grazing of wild horses, European bison and back-bred aurochs restored the long gone landscape mosaic and created conditions that allow for the survival and return of endangered butterflies, bees and beetles. “Insects need various types of environment for their various stages of development. Often, larvae or caterpillars need various environments during one single day: for feeding, and for sheltering from the sun and predators. Moreover, they need to find these varied biotopes quite close to one another, because they can only move several metres at most. It is the manifold mosaic of biotopes that the large ungulates create that is the ideal environment for many insect species,” Miloslav Jirku from the Biology Centre of the Czech Academy of Sciences explained.
In some places, large ungulates graze grass low, in others they leave it higher, and by grazing grasses, they provide space for blooming plants that produce nectar. Variety is also supported by the fact that by moving through the country, they create beaten paths and dust pools. Even the droppings of large ungulates are a source of minerals for butterflies, and a cradle for dung beetles to raise their young.
Grazing land for large ungulates is not a Czech “invention”, but has been used by conservationists in Western Europe for more than three decades. In the Czech Republic, the method has been in use since 2015, and currently, large ungulate grazing is taken advantage of in five reserves. “In this way, “pockets” can be created in the countryside, where endangered species can survive until conditions have improved on a larger scale,” Dalibor Dostal, director of European Wildlife conservation organisation said.
Czech reserves are still too small to be a safe haven for the rescue of many insect species. Dalibor Dostal continues: “Our colleagues in Germany use areas of 1,000 hectares for their projects.” If such large reserves are created in the Czech Republic, too, it will be an important step for the rescue of pollinators and other species of endangered insects. Scientists warn that further decimation of insects could lead to the destruction of whole ecosystems and life cycles.
Nature cannot function without insects, as it is insects that are the basis of the food pyramid, right after plants. Due to a dramatic decrease in insects, millions of years of functional relationships between organisms are decaying, and disruption of the function of whole ecosystems is imminent. The landscape perceptibly lacks insect pollinators, for example. “Not only are wild plants dependant on their indispensable work, but also the production of a substantial part of crops that feed us humans. Moreover, each group of plants, including agricultural plants, needs slightly different pollinators, and they must be in large quantities in order to manage to pollinate blossoms. Humans and nature alike will have huge problems without insects, or more precisely, without a large quantity of insect species,” Miloslav Jirku warned.
The depletion of insects influences all groups of organisms, including birds. They don’t have enough insects to feed on. Insects are needed even by birds that normally feed on seeds to feed to their young.
Photo: Wikimedia / Wenkbrauwalbatros
