Unsuccessful rubidium marking of American dog tick (Acari:Ixodidae) adults

In an effort to determine if Dermacentor variabilis (Say) adults could be marked with rubidium (Rb), unfed nymphs were placed on laboratory mice and the mice subsequently injected with rubidium chloride (RbCl). Nymphal feeding duration was not affected by the presence of Rb in their hosts. D. variabilis adults (24-48 h old) that had fed as nymphs on RbCl-injected hosts contained approximately 13 parts per billion (ppb) of Rb, and adults that had fed as nymphs on control mice contained approximately 20 ppb of Rb. There was no difference in Rb concentration among D. variabilis adults obtained from different RbCl-injected mice. Although Rb has been shown to be a noninvasive marker for D. variabilis nymphs, D. variabilis adults were not successfully marked using the same technique.