Insects are declining!
Insects are the animal class with the most species on earth. They are by far not all discovered yet – but we know, that they are declining fast.
[Download pdf, important studies, 5 pages in German]
The number of insect species is estimated to be two to ten million. Only one million is already scientifically described. In Germany, insects are going down heavily, as studies show. Over 30% of the insect species are endangered. Almost 5% are extinct. In parts of Germany, environmental organizations counted 80% less insects than 15 to 20 years ago. A similar development can be observed in Austria and Switzerland.
The world’s population grows and thus also the areas claimed from human beings as their living space. Natural habitats are sealed, also the ones that served as biotopes for insects and other creatures.
The production of food also needs areas. The industrial agriculture for example reduces biodiversity, because pollinating insects do not find enough feed in monocultures. Also insecticides used for private and agricultural purpose contribute to the decline of insects. Observing species loss today is a result of human behavior some years ago, because it occurs with a time lag. As environmental pressures continue, the number and species of insects are likely to decline further on.
Insect Respect literature references on this topic:
- Hallmann, C.; Sorg, M. et al.: More than 75 percent decline over 27 years in total flying insect biomass in protected areas. In: PLOS One, 18.10.2017. [Available under: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185809 ]
- Sánchez-Bayo, F.; Wyckhuys, K. (2019): Worldwide decline of the entomofauna: A review of its drivers. In: Biological Conversation. Amsterdam: Elsevier. [Available under:
- Binot-Hafke, Margret & Sandra Balzer, Nadine Becker, Horst Gruttke, Heiko Haupt, Natalie Hofbauer, Gerhard Ludwig, Günter Matzke-Hajek & Melanie Strauch (Red.) (2011): Rote Liste gefährdeter Tiere, Pflanzen und Pilze Deutschlands. Band 3: Wirbellose Tiere (Teil 1). Landwirtschaftsverlag, Münster. Reihe: Naturschutz und Biologische Vielfalt 70 (3) des Bundesamtes für Naturschutz, Bonn-Bad Godesberg.
- HORST GRUTTKE, MARGRET BINOT-HAFKE, SANDRA BALZER, HEIKO HAUPT, NATALIE HOFBAUER, GERHARD LUDWIG, GÜNTER MATZKE-HAJEK & MELANIE RIES (Red.) (2016): Rote Liste gefährdeter Tiere, Pflanzen und Pilze Deutschlands. Band 4: Wirbellose Tiere (Teil 2). Landwirtschaftsverlag, Münster. Reihe: Naturschutz und Biologische Vielfalt 70 (4) des Bundesamtes für Naturschutz, Bonn-Bad Godesberg.
- NABU, 2016: Dramatisches Insektensterben – Rückgang um 80 Prozent in Teilen Deutschlands. — https://www.nabu.de/news/2016/01/20033.html.
- European Environment Agency (2013): The European Grassland Butterfly Indicator: 1990–2011. EEA Technical report No 11/2013. ISBN 978-92-9213-402-0; doi:10.2800/89760.
The study, conducted by Francisco Sánchez-Bayo and Kris A.G. Wyckhyus, describes the drivers of the worldwide decline of the insect population. It deals in detail with the four main causes of biodiversity destruction: 1.) habitat loss and conversion to intensive agriculture, as well as urbanization; 2.) pollution mainly from synthetic pesticides and fertilizers; 3.) biological factors, including pathogens and introduced species and 4.) climate change. It also analyses how established behaviours need to be re-thought in order to slow down or reverse the trend of species extinction.