Insects play a very important role in our ecosystem. A large part of insects is advantageous and available for pollination of plants, regulation of pests, recycling of dead plants and animals, or as animal feed. Biodiversity is closely tied to life on Earth, and its reduction can have irreversible detrimental consequences for the entire animal kingdom, including us humans.
The destruction of the natural environment, the breeding of non-native species and global climate change are considered to be the causes of the decline in the number of insects in nature. The destruction of the natural environment is mainly due to intensive agriculture, where pesticides and insecticides are widely used, urbanization, especially the spread of artificial lighting, and industrialization. The most affected species of insects include bees, butterflies, moths, beetles, dragonflies and punches. Many affected species are important pollinators and thus indirectly make a positive contribution to the yield of the crops on which humans and animals feed.
Studies of this issue are currently (2019) ongoing. In 2017, for example, a study was published which found that the total biomass of flying insects in Germany had decreased by 75% over the last 26 years, which is a year-on-year decrease of 5.2%. In Scotland, it was found that between 1970 and 2002, total insect biomass was reduced by 66%. It is also known that insect loss is uneven between species and in different environments. This is mainly due to the fact that different species are differently able to adapt to ongoing environmental changes. Species with reduced mobility are particularly at risk of extinction. The total loss of insect biomass worldwide is estimated at 2.5% per year.
There are several problems in interpreting the results of insect decline. These include missing data on past insect counts, recent decline in interest in etymology, misinterpretation of species-specific results, or unofficial subjective observations of humans, such as reducing the number of insects killed when hitting the windshield of a moving vehicle. It is also important to note that most studies deal with the reduction of insect biomass, which may not necessarily correlate with the number of insects, especially for specific species. Another problem with the studies is their concentration on Western Europe and North America, but the largest numbers of insects live in tropical areas. However, as this is a major global problem and threat, it can be assumed that the results of further studies will be presented in the coming years and the impacts on human society will be specified.