ENVS 2210 Lecture Notes - Pesticide, Neonicotinoid, Pyrethroid

• School: University of Guelph
• Department: Environmental Sciences
• Course: ENVS 2210

Document Summary

Chemicals or biological agents used to control pests. Toxic to target and non-target organisms like the honey bee and other pollinators. They are a bee health issue, particularly during the spring. Varroa mite is main cause of winter losses pesticides are the main cause of spring losses. Most are nerve toxins (interfere with nerve transmission) Insecticides insects most dangerous to the bees. Inorganics (arsenic, sulphur) highly toxic to bees. Organics (organophosphates and carbamates) most are toxic. Botanicals (pyrethroids, nicotines, avermectins) vary in toxicity to bees. Neonicotinoids newly developed insecticides with a nicotine type of molecule very bad for bees. Toxicity poisonous potency (depends on dose) Exposure route and length (ingestion, physical contact?) With increased toxicity and or exposure, there is increased hazard. Lower the ld50, more toxic the substance is for bees. Poisoning of bees is a major problem. More than 50,000 colonies die in canada and 500,000 in usa. 25% pesticides toxic to bees (usually insecticides)