Bee Decline: Causes and Consequences

Short: Bee decline describes the globally observed, sometimes dramatic decrease of honeybee and wild bee populations. Since bees are essential for pollinating numerous crop plants, their decline has far-reaching consequences for agriculture and ecosystems.

In more detail: Usually several factors act together simultaneously, which complicates causal research and makes simple explanations unlikely.

In detail

• Pesticides: Certain insecticides, especially neonicotinoids, weaken bees’ nervous systems and impair orientation and reproduction.
• Varroa mite: This parasite infests honeybee colonies, transmits viruses, and is considered one of the most important individual factors in honeybee decline.
• Habitat loss: Monocultures and the decline of flowering wild plants significantly reduce the food supply for wild and honeybees.
• Climate change: Shifting flowering times increasingly mismatch with pollinating insects’ activity rhythms, leading to food shortages.
• Economic importance: A significant portion of global food production depends directly or indirectly on bee pollination.
• Wild bees particularly affected: Unlike well-documented honeybees, the decline of many wild bee species is less researched but often even more dramatic.
• Protective measures: Planting flowering strips, avoiding pesticides, and creating wild bee nesting sites are among the most effective individual contributions to bee protection (insekten-und-bestaeuber, biodiversitaet-und-artenvielfalt).