Correlation between haemolymph ecdysteroid titre, salivary gland degeneration and ovarian development in the Ixodid tick, Amblyomma hebraeum Koch

In the female tick, Amblyomma hebraeum Koch (Acari: Ixodidae), the salivary glands degenerate and vitellogenesis begins, provided the tick exceeds a critical weight (approx. 300–350 mg). The following were measured in ticks: (1) at various times following normal engorgement (1000–3000 mg) and (2) at various stages (weights) of the feeding cycle, 7 days after removal from the host: salivary fluid secretory competence and ecdysteroid content (by radioimmunoassay) of haemolymph and ovary extracts. (1) Haemolymph ecdysteroid titre rose from