Term of Award


Degree Name

Master of Science in Biology

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Committee Chair

James H. Oliver, Jr.

Committee Member 1

Daniel V. Hagan

Committee Member 2

Sara N. Bennett


Six of the 18 synganglial neurosecretory regions of Ornithodoros parkeri showed significant cyclic changes in unfed and 8, 24, 48, 96 hour and 10 day post-fed third stage nymphs (N3s), and 24 hour postecdysed N4s. Possible neurohormonal functions are discussed. When ingested or applied topically, B-ecdysone caused mortality or double molts in N3s and mortality or supernumerary molts in adult females. Parabiosis did not induce molts in intended recipient ticks, but did significantly delay molting in fed partners (donors) which frequently double molted. As evidenced by cuticular changes, ligations appear to have confined molting to the posterior portion of ticks regardless of whether the synganglion was in that portion; however, all ticks which actually molted shed the cuticle at both ends. Results of experiments involving synganglial transplants and injections of crude synganglial extracts were inconclusive.

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