Variations in ecdysteroid levels in 5th instar larvae of Schistocerca gregaria in gregarious and solitary phases

Moulting hormone levels in whole bodies of 5th instar S. gregaria were determined throughout the 5th larval instar using gas chromatography with electron capture detection of the derivatized hormone. No differences were found between hormone levels in insects in the gregarious and solitary phase. No evidence for the existence of polar ecdysteroid conjugates used for storage or transport of these hormones was found. Approximately one tenth of the 20-hydroxyecdysone observed in the gregarious insects was detected in the faeces, almost equally divided between free hormone and polar conjugates of it.