Pesticides      Since 1994, the number of wild bees in Switzerland has decreased by about half. It is therefore not the honeybees but primarily the wild bees that are declining. A major reason for this is the use of various pesticides. While the chemical cocktail doesn't kill the bees outright, it severely impairs their sense of orientation.
As a result, wild bee species such as the red mason bee (Osmia bicornis) can no longer find their nesting sites and have difficulty finding potential mates.

Monocultures    The concept of monoculture has only gained prominence since the post-World War II period. The use of the insecticide DDT enabled large-scale cultivation of vast areas with the same plant species. Despite the ban on DDT, monocultures have become the dominant agricultural practice. These green deserts represent a significant loss of habitat for a wide range of insect species.
Since 1994, the number of butterfly species has declined by 40%. The intensification of agricultural landscapes through regular mowing of meadows and monocultures is leading to species such as the fritillary (Melitaea parthenoides) being increasingly displaced from their natural habitats.

Overfertilization      Monocultures are not the only cause of habitat depletion for insects. Overfertilization of fallow fields allows nitrogen-loving plant species like dandelions to outcompete other plants, significantly reducing biodiversity in these areas.
The two-toned bush-cricket (Metrioptera bicolor) is a grasshopper species that is increasingly affected by this loss of habitat. The number of all grasshopper species in Switzerland has declined by more than 50% since 1994.

Transfer of Pesticides and Fertilizers      Through weather influences such as wind and rain, pesticides and fertilizers are also transferred to areas not intended for them. Many aquatic insect species are highly sensitive to habitat pollution.
One such species is the emerald dragonfly (Ophiogomphus cecilia), which is aquatic during its larval stage. Due to its sharp decline and the threat to its habitat, it is classified as critically endangered in Switzerland.

Tidy Landscapes      Residential areas are often barren wastelands for insects. Trimmed lawns bordered by monotonous thuja hedges are practically worthless for our native insect species. The lack of plant diversity and the absence of dead wood offers insects neither food nor habitat.
The great rose chafer (Protaetia speciosissima) is a species that, in its larval stage, feeds primarily on the dead wood of oak trees. The adult beetles are often found in gardens. In Switzerland, this beetle species is considered critically endangered.

Consumer Behaviour      Human consumption habits have a significant impact on insect habitats. At the same time, we are highly dependent on insects. In Switzerland alone, pollination by honeybees and wild bees results in a fruit and vegetable yield worth 479 million Swiss francs. In forestry, it is difficult to estimate the consequences of the insect die-off on the recycling of dead material. Thus, a continued extinction not only means a loss in nature but also brings economic consequences.

Light Pollution      Light pollution in residential areas plays a significant role in the decline of insect populations. Artificial light disrupts the natural daily rhythms of insects. They are either burned by light sources or fly around them until they die of exhaustion. Many nocturnal insect species are poorly understood, so the consequences of a growing decline in these species are difficult to assess.
The mottled umber moth (Endromis versicolora) is a striking moth species, with females being particularly affected by light pollution. They are exclusively nocturnal and therefore often fall victim to artificial light sources, which makes them a critically endangered species as well.