title: Expression of acquired immunity to immature stages of the tick Rhipicephalus evertsi evertsi by rabbits and guinea-pigs.
abstract: Acquired immunity in guinea-pigs and rabbits to immature stages of the two-host tick Rhipicephalus evertsi evertsi Neumann was demonstrated. Repeated infestations of both hosts with larvae resulted in a significant reduction in the weight of later engorged nymphs. A sharp decline in the numbers of nymphs which successfully fed on both hosts was also observed. This study provides evidence for a gradual decrease in the mean weight of engorged nymphs towards the end of the detachment period suggesting that, in two-host ticks, the onset of nymphal feeding acts as an immune booster in a host already primed by the larval feed and that this results in a reduced feeding performance.
authors.affiliation: Department of Biology, Medical University of Southern Africa, Medunsa.
authors.forename: F C
authors.initials: FC
authors.lastname: Clarke
authors.forename: D A
authors.initials: DA
authors.lastname: Els
authors.forename: A
authors.initials: A
authors.lastname: Heller-Haupt
authors.forename: Y
authors.initials: Y
authors.lastname: Rechav
authors.forename: M G
authors.initials: MG
authors.lastname: Varma
mesh_terms: D000818:Animals; D005260:Female; D006168:Guinea Pigs / Q000469:parasitology*; D007110:Immunity, Active; D007814:Larva / Q000276:immunology; D009758:Nymph / Q000276:immunology; D011817:Rabbits / Q000469:parasitology*; D012376:Rodent Diseases / Q000276:immunology*; D013984:Tick Infestations / Q000276:immunology / Q000662:veterinary*; D013987:Ticks / Q000276:immunology*