Chemical stressors
  • Insecticides, including pyrethroids and systemic neonicotinoids such as imidacloprid, thiamethoxam and clothianidin. Insects can be poisoned by spray, dust and through consumption of pollen and nectar.
  • Fungicides such as chlorothalonil, which is used widely in the US on peanuts, potatoes, tomatoes and other crops.
  • Antibiotics including oxytetracycline, which are used to combat diseases such as American Foulbrood.
  • Industrial pollutants can also have effects on the behaviour and health of bees. For example, manganese – a heavy metal commonly used in the production of steel and batteries – can accumulate in the nectar of plants where it is consumed by bees. One study suggests that manganese consumption has a negative impact on bees’ foraging abilities.