Butterflies

Zitronenfalter, Birkenspanner oder Kleiner Kohlweißling: Sind wir in unserer Kindheit im Frühling noch ganz idyllisch von ihnen begrüßt worden, hält man mittlerweile vergebens nach ihnen Ausschau. Zitronenfalter und Großes Ochsenauge könnten bald ausgestorben sein: Immer mehr Schmetterlingsarten verschwinden. Seit 1990 sind 50 Prozent aller Tagfalter-Arten in Europa verschwunden, 80 Prozent stehen auf der Roten Liste der bedrohten Tierarten.

There has been a lot of discussion about the decline in bee populations and its dire consequences for agriculture. We have also talked about the efforts to save the monarch butterfly, whose numbers have been dropping dramatically over the years. But the rest of the insect world does not get much attention. For the most part, we think of insects as a nuisance or as potential pests. A number of studies in recent years in Germany, Great Britain, and in the United States have concluded that many insect populations worldwide are in severe decline, and this is not a good thing.

Traditional farming and gardening has long taken a straightforward approach: if an unwanted plant or animal interferes, it is to be killed. We even developed a special vocabulary to help justify our actions: the animals were “vermin” and the plants were “weeds”. And, in the case of one hen-house plunderer, we came up with the elaborate ritual that is fox hunting, complete with a special ‘language of avoidance’ that anthropologists have found in cultures around the world (the fox is a “dog”, its face is a “mask”, its tail is a “brush”, the dogs are “hounds”).

Pflanzenschutzmittel aus der Gruppe der Neonicotinoide können nicht nur Honigbienen, sondern auch Wildbienen und Schmetterlinge gefährden. Das zeigen einmal mehr aktuelle Forschungsergebnisse britischer, US-amerikanischer und deutscher Wissenschafter. Für ihre Untersuchung analysierten Forscher um den Entomologen Ben Woodcock, wie sich der großflächige Einsatz von Neonicotinoiden auf 62 Wildbienen-Arten in Großbritannien von 1994 bis 2011 auswirkte. 2002 waren die Pestizide dort erstmals zugelassen worden.

The link has been established before. When we reduce pests with most insecticides, they discriminate too little between friend and foe. We can’t always see butterflies as friends because of the function of their caterpillars. However, as birds, reptiles and mammals rely on these insects and their relatives for food, what happens is simply Silent Spring, all over again.

"Wann haben Sie das letzte Mal einen Bläuling gesehen?", fragt der BUND-Regionalverband südlicher Oberrhein in einer Presseerklärung. Sie ist illustriert mit einem Foto des himmelblauen Kleinschmetterlings, an dessen Ecke ein Trauerflor angebracht ist. Was ist da los? "Wir erleben gerade einen massiven Rückgang an Schmetterlingen, sowohl der Arten als auch der Individuen", sagt Geschäftsführer Axel Mayer. Bemerkt wird der Schwund auch von naturinteressierten Gartenbesitzern, die sich bisher im Sommer immer über die bunten Falter gefreut haben.

Rund 3700 Arten von Faltern oder Schmetterlingen (Lepidoptera) gibt es in Deutschland, darunter - neben der riesigen Zahl an Nachtfaltern und Kleinschmetterlingen - etwa 180 oft farbenprächtige Tagfalter, die überwiegend tagsüber unterwegs sind. Doch die Vielfalt schwindet: In Bayern wurden seit 1766 etwa 3250 Arten nachgewiesen. "Ab 2001 fanden wir nur noch 2819 Arten. Weit mehr als 400 Spezies sind nicht mehr nachweisbar, was einem Rückgang von 13 Prozent entspricht", sagt Jan Christian Habel von der Technischen Universität München.

Nationally hay meadows are in decline, according to a survey carried out in the 1980s, over 97 per cent of flower rich grasslands have been lost since 1930 and those that remain are decreasing in wildlife value. Northern England was once covered in species rich upland flower meadows and even here it is estimated that only a 1000 ha remain. When a meadow is lost it is not just the flowers that disappear but the hundreds of insects including many species of butterfly and bee that rely on them and even the bats that feed on the insects.

Of the 117 butterfly species recorded in 1840 in the survey site, a protected habitat in the south-German state of Bavaria, just 71 are still found today, said the authors of the study recently published in the journal Conservation Biology. "Species requiring a specific type of habitat or food source, such as the "elegant white and ochre-spotted" hermit butterfly, are threatened with extinction in Germany. Extinction rates over the last 30 years are "particularly alarming," says the study.

According to wildlife charity Butterfly Conservation, 44 out of the country’s 58 butterfly species have seen a drop in their populations, leaving some species at risk of extinction in the U.K. Common butterflies of the general countryside as well as specialist butterflies that require particular habitats have declined.\Richard Fox, head of recording at Butterfly Conservation, tells Newsweek that the dramatic decrease in the number of garden butterflies is “severe and statistically significant.”