VITELLOGENIN CONCENTRATIONS IN THE HEMOLYMPH AND OVARIES OF IXODES-SCAPULARIS TICKS DURING VITELLOGENESIS

The vitellogenin and vitellin concentrations in the haemolymph and ova ries of Ixodes scapularis females were determined using a double sandw ich enzyme-linked immunosorbent assay. The level of vitellogenin in th e haemolymph began to increase just prior to tick detachment from the host and continued to increase until 2 days after detachment. There wa s a slight decrease in the vitellogenin level 4 days after detachment, but a second peak was observed approximately 5 days after oviposition . Subsequent to oviposition, the vitellogenin levels in the haemolymph quickly decreased. The concentration of vitellogenin in the haemolymp h ranged from 1.55 to 11.48 mu g mu l(-1) during the period after drop ping from the host through oviposition. The concentration of vitellin in the ovaries began to increase as the female began rapid engorgement (0.03 mg per female) and declined after oviposition (0.1 mg per femal e).