Identification of Arthropod Blood Meals Using Rubidium as a Marker: A Preliminary Study

Abstract

A technique for identifying blood meals of medically important arthropods using rubidium (Rb+) as a marker is presented. Isotonic Rb+ was injected into host animals, and hematophagous arthropods that fed on the animals were later analyzed for Rb+ using flame spectrophotometry. In these laboratory studies, all Culex tarsalis fed on Rb+-marked Japanese quail ( Coturnix coturnix ) ingested easily detectable amounts of Rb+. Mosquitoes retained measurable amounts of Rb+ as long as 7 days after feeding on quail injected with 500 mg Rb+/kg as long as 11 days before the mosquitoes fed. Data are presented on naturally occurring background Rb+, Rb+ concentration in the circulating blood of 3 vertebrate species, effect of the marking procedure on vertebrate behavior, and effects of marking on mosquito feeding frequencies. All of these data indicate that Rb+ marking is feasible.