Juvenile hormone agonists as pesticides

2 Juvenile hormone agonists as pesticides Methoprene is a juvenile hormone mimic preventing metamorphosis and is used to control a wide variety of insects, especially Diptera and Pharaoh s 

Ecdysone induces the larval-pupal metamorphosis in the absence of JH or a JH-active insecticide, but the presence of active compounds leads to a new larval stage at ecdysis, or to the development of larval-nymphal, larval-pupal, or larval-adult intermediates that are unable to give rise to normal adults. Treated pupae (e.g., tobacco cutworms treated with pyriproxyfen) may develop into normal adults. However, the females are unable to deposit eggs because a substance that induces oviposition behavior after mating is not released in the hemolymph. Other physiological and behavioral effects of JH-active insecticides are also observed. 

The toxicity to mammals of the JH-active insecticides is very low. In the World Health Organization (WHO) classification system, they are all in class III (Table V). The rat oral LD50 (lethal dose in 50% of the population) is 5000 mg/kg, and the toxicity to fish and birds is also low. Indications for mutagenic, carcinogenic, or teratogenic effects are not found. To bee larvae, JH-active insecticides are, of course, rather toxic (e.g., 0.1 pg/bee for hydroprene), while for adult bees they are essentially nontoxic. 

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