Biochemical and Physiological Studies of Certain Ticks (Ixodoidea). Absence of Sterol Biosynthesis in Dermacentor Andersoni Stiles (Acarina: Ixodidae)1

Abstract

Cholesterol is the only free circulating sterol in hemolymph of ticks of the families Ixodidae (Hajjar, 1972, J. Med. Ent. 9: 281–85) and Argasidae (Maroun, 1972, J. Med. Ent. 9: 161–67). The lack or partial inhibition of the enzymatic pathways for sterol biosynthesis in insects has been suggested (Gilbert, 1967, Adv. Ins. Physiol. 4: 69–211) but there have been no comparable data for ticks. Thus we investigated the biosynthetic pathway of sterols in DERMACENTOR ANDERSONI Stiles (family Ixodidae).