Biological,radiochemical and physicochemical evidence for the low activity of disconnected corpora allata in locust

The rate of juvenile hormone biosynthesis by locust corpora allata after transection of the nervi corporis allati 1, was measured in vitro using both radiochemical assay and gas chromatography—mass spectroscopy analyses. Incubations in different culture media or in pure haemolymph result in a low rate of juvenile hormone biosynthesis by disconnected glands. In vivo studies using juvenile, chromatotropic and gonadotropic effects of the corpora allata confirm the low activity of the disconnected glands. Furthermore, animals with disconnected corpora allata appear to be more sensitive to corpora allata implantation than control hosts.