20-Hydroxyecdysone stimulates molting in pycnogonid larvae (Arthropoda, Pantopoda).

Molting in pycnogonid larvae, Pycnogonum litorale, is accelerated by exposing the animals to 20-hydroxyecdysone at concentrations of 10 to 1000 ppm during Days 5 to 9 after the first ecdysis. Hormone application at the beginning or at the end of the molt cycle, as well as treatment all through the molt cycle, delays or even inhibits the molt by upsetting the sequence of molting processes.