PATHWAYS OF DEGENERATION OF HALLER SENSORY ORGAN DURING THE LIFE-CYCLE OF THE TICK HYALOMMA-ASIATICUM

A study of regeneration in nymphs and adults of the Asiatic desert tic k, Hyalomma asiaticum, from which forelegs had been amputated during t he previous instar, revealed that regenerated Haller's sensory organs exhibited significant changes in structure. Adult regenerates possesse d atavistic features in terms of the number and topography of differen t sensillar types. Regularity in these changes was similar to that dem onstrated in regenerates of Ixodes ricinus (Leonovich and Belozerov [1 992] Exp. Appl. Acarol., 15:59-79). Nymphal regenerates, by contrast, had larval features of the parent species. An hypothesis is presented about the ontogenesis of the complete, peripheral, poly-nodal sensory organ as a process in which the initial cell differentiation of cells begins at different starting points. (C) 1995 Wiley-Liss, Inc.