‘The disappearance of the butterflies’: How fertilization and pesticides are decimating the butterflies | Science

Josef H. Reichholf (Lower Bavaria, Germany, 76 years old) explains that he is barely conscious of his first memories of butterflies; he used to see them flitting around the garden of his house. However, he has not forgotten when, while still small, he captured one, with great care not to damage it, to be able to observe it calmly: “It was so impressive that it remained until now in my memory.” Over the years he began to study the number and abundance of these insects, especially the nocturnal ones, which account for 90% of all butterflies that fly daily in Central Europe and whose number of species is 10 times greater than that of the diurnal, as detailed by the biologist. “The importance of those that fly at night is much greater than those that fly during the day. They are food for others. They act as key elements in the ecosystem ”, he points out.

After more than two decades of research, this evolutionary biologist realized that the number of these insects is decreasing. The observations have continued over the years and he has just published his latest book in Spain, called The disappearance of the butterflies (Critical), where it shows the results. It reflects the decrease in nocturnal butterflies by more than 80% in the last 50 years in his study area: the periphery of a town in southeastern Bavaria. The causes are multiple, but the main ones are in the hands of humans with the extensive use of pesticides and fertilization, he says.

“The nocturnal butterflies act as key elements in the ecosystem”

Reichholf emphasizes that, although it is somewhat generalized, countries such as Germany, the Netherlands or others in the north are much more affected by this decline in butterflies than those in the south. The most important causes of this phenomenon are related to cultivation. The problem with pesticides, he argues, is that they not only act against pests, but also outside the fields, on natural vegetation. Regarding fertilization, the scientist explains that very useful conditions have been created for a small number of plant species and that these displace the rest: “The vegetation is becoming very simple, made up of a few species that are highly tolerant to nitrogen and that outperform the most sensitive plants. Therefore, the butterflies are going to lose their plants ”. In addition, it specifies that near the ground the vegetation creates “colder and wetter conditions”, but that these are “very different” in the places where it is fertilized at a higher level than normal. This is the reason why even in non-poisoned areas, the number of butterflies is decreasing. Contrary to what a majority might think, cities with gardens and parks act as “a little refuge” for smaller animals.

Josef H. Reichholf in 2018
Josef H. Reichholf in 2018Peter-Andreas Hassiepen

It is necessary to add conservation measures in non-agricultural areas, such as road shoulders, which especially affect the habitat of butterflies and which, with these actions, even destroy them.

Global warming also has an important place in this matter. Whether it will affect positively or negatively in the following years will depend on the location: “In the short term, global warming in the northern Alps will be better for butterflies and other insects, since most of the latter depend on warm temperatures. However, there are landscapes that are too large that are drying up and turning into deserts and, therefore, the abundance of butterflies will decrease again ”, he concludes.

The consequences of reduced Lepidopteran populations are reflected in changes in other animals. Reichholf explains it through birds, whose species, in many cases, depend on certain “minimal amounts” of caterpillars and flying individuals such as day and night butterflies.

Government policies

The author, who has published a dozen books in his country, criticizes that “the action of the German Government is more or less close to nothing.” “The best results have been obtained through the involvement of nature conservation corporations and ordinary people whose gardens are pesticide-free. Private commitment is more important than government actions for the protection of the environment ”. Another point of contention is the protection law for the preservation of butterflies because it considers that the current legislation does not work since it does not take into account the relevant issues. “It is a small part of the population that poisons and destroys nature,” he accuses.

“Agriculture must become a symbiosis with the general population and not a parasite”

This problem also affects the European Union. Reichholf proposes a regulation that combines agricultural subsidies with effects that are based on nature and not only on productivity. “Currently, the interest of the majority of the European population in terms of the amount of fertilizers and the amount of pesticide use for agricultural production is not considered. Agriculture must become a symbiosis with the general population and not a parasite ”, he says.

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George Holan

George Holan is chief editor at Plainsmen Post and has articles published in many notable publications in the last decade.

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