Free ecdysteroids in adult male crickets, Gryllus bimaculatus

ABSTRACT. Ecdysteroid titres were determined in testes, fat body, muscles, haemolymph, carcass tissue, spermatophores, and faeces of males of the Mediterranean field cricket, Gryllus bimaculatus de Geer, throughout its adult life span. Considerable amounts of free ecdysteroids are concentrated in the testes and the fat body. The ecdysteroid titres were only slightly influenced by environmental temperature. In all tissues except the fat body, ecdysone and 20-hydroxyecdysone were the predominant ecdysteroids present. In faeces, highest ecdysteroid concentrations were found at the time of lowest levels in tissues.