Methoprene

Methoprene, an insect juvenile growth hormone mimic, is a growth-regulating insecticide that manifests its toxicity to target organisms by acting as a juvenile hormone agonist^[1][2]. In Vitro: Methoprene reduces the growth rate of daphnids with evidence of only a single concentration-response line, having a threshold of 12.6 nM. Molt frequency is reduced by methoprene in a concentration-dependent manner, with a response curve corresponding to a 2-segmented line and thresholds at 4.2 and 0.21 nM. An endpoint related to reproductive maturation, the time of first brood deposition, is also affected by methoprene, with a clear concentration-dependent response and a NOEC of 32 nM. Methoprene reduces fecundity according to a 2-segmented line, with thresholds of 24 and < or =0.18 nM. Methoprene elicits significant toxicity to endocrine-related processes in the 5-50 nM concentration range^[1].