Rhipicephalus sanguineus and R. turanicus (Acari: Ixodidae): Closely Related Species with Different Biological Characteristics

Abstract

Life cycle parameters of 2 closely related tick species, Rhipicephalus sanguineus Latreille and R. turanicus Pomerantsev, were studied under laboratory conditions. Both Rhipicephalus, which have small adults, demonstrated the same adaptations as large tick species inhabiting deserts and semideserts: high reproductive rate, decrease in egg size, and an increase in interstage growth to compensate for the smaller size at birth. Pronounced quantitative differences between both species were discerned in relation to these adaptations. Female R. turanicus produced twice as many eggs as R. sanguineus which was facilitated by the greater amount of blood engorged by females and by the smaller egg weight in R. turanicus as compared with R. sanguineus. In all developmental stages, the weight increase from unfed to fed ticks was greater in R. turanicus than in R. sanguineus (23% higher in larvae, 118% in nymphs, and 26% in females). The increase in weight in R. turanicus from the unfed larva (0.013 mg) to the unfed female (3.31 mg) was 254-fold, and in R. sanguineus it was 127-fold (from 0.021 to 2.54 mg). In nymphal R. turanicus, the higher density and the greater height of the dorsal epicuticular folds, as well as procuticular indentations found inside the folds allow this tick to stretch its alloscutum during blood engorgement to a greater extent than R. sanguineus. The rates of blood ingestion (for nymphs and females), egg maturation, and metamorphosis were 1.1-1.7 times greater in R. turanicus than in R. sanguineus. A life cycle strategy with both a higher reproductive rate and faster development in R turanicus may be explained by its greater dependence on environmental factors than that in R. sanguineus.

Potential risk of pathogen transmission by acaricide-poisoned ticks

“…In each test involving tick feeding, 10-12 ticks were fed on laboratory animals: nymphal ticks on guinea pigs and female ticks on rabbits (together with an equal number of males). The other details of tick maintenance and feeding have been described in detail in our previous publications (Uspensky, 1974(Uspensky, , 1982Uspensky et al, 1975Uspensky et al, , 1977Ioffe-Uspensky et al, 1997).…”

Incongruent effects of two isolates of Rickettsia conorii on the survival of Rhipicephalus sanguineus ticks

“…The founders of both colonies were indentified morphologically as Rh. sanguineus according to the published guides (Feldman-Muhsam 1952;Ioffe-Uspenskiy et al 1997;Pegram et al 1987;Walker et al 2000).…”

Complete Mitochondrial Genome Sequence Data Provides Genetic Evidence That the Brown Dog Tick Rhipicephalus sanguineus (Acari: Ixodidae) Represents a Species Complex

“…For example, R. sanguineus was considered as a species complex of about 10 closely related species based on traditional morphological approach 5,6. However, the systematic status of the members of the R. sanguineus group is still unclear, resulting in their misidentification 18,19. To date, phenotypic techniques have considerable limitations for the precise identification and differentiation of all the members belonging to this group 6.…”