Presence of ecdysone and ecdysterone in the tickAmblyomma hebraeum Koch

Summary Ecdysone and ecdysterone, the moulting hormones of insects and crustaceans, are also present in nymphs of the tickAmblyomma hebraeum. They were demonstrated by means of radioimmunoassay and of gas-liquid chromatography combined with mass fragmentography or mass spectrometry of their trimethylsilyl-drivatives.Acknowledgments. We thank Proff. A. Aeschlimann and C. Noirot and Dr J. Delachambre for their help and encouragement. We are grateful to Proff. Maume and Padieu (Département de Biochimie, Université de Dijon) for the use of the LKB 9000 GLC-MS, and to Drs M. L. De Reggi, M. H. Hirn and Prof. M. A. Delaage for the gift of some RIA-antigens and antibodies. We thank Ciba-Geigy Ltd for the supply with ticks. The work was in part supported by grant Nr. 3. 734. 76 of the Swiss National Science Foundation and by a grant of the Emil Barrel Stiftung.