A revision of two distinct species of Rhipicephalus: R. microplus and R. australis

Abstract

Rhipicephalus ( Boophilus) species are monoxenous ticks with seasonal distribution in tropical and subtropical regions. For many years, Rhipicephalus micropluswas considered as a single species; however, further analysis split these ticks into two distinct species. Because R. microplusand R. australisshare similar attributes, it is hard to discriminate these two species and explain the changes in the classification of these parasites over the past decades. The reappearance of R. australisis an outcome of new research, which has afforded to better characterize these probably cryptic species. Evidence based on morphological features, the lack of conspecificity, microsatellite markers, mitochondrial 12S and 16S ribosomal DNA, and mitochondrial genome supports the re-classification of R. microplusas different species. Therefore, populations of R. microplusfrom Australia, Cambodia, Philippines, Indonesia, New Caledonia, Borneo, New Guinea, Tahiti and parts of Southeast Asia were recently reinstated as R. australis. Moreover, a better knowledge on the speciation between these two species could pave the way to important advances in tick control strategies.

Seasonal Dynamics, Record of Ticks Infesting Humans, Wild and Domestic Animals and Molecular Phylogeny of Rhipicephalus microplus in Khyber Pakhtunkhwa Pakistan

“…Previous studies have enlisted intraspecific variations in genus Rhipicephalus based on morpho-taxonomic complications in identification at species level (Lempereur et al, 2010; Barker and Walker, 2014). Morphological variations in Rhipicephaline ticks make it difficult to distinguish these tick species morphologically and to date, several valid species of Rhipicephalus ( Boophilus ) have been confirmed (Estrada-Peña et al, 2012; Guglielmone et al, 2014; Ali et al, 2016; Coimbra-Dores et al, 2018; Roy et al, 2018). The morpho-taxonomy of R. microplus (cattle tick) has been challenged in the last few years due to a hypothesis suggesting that biogeographical and ecological separations have occurred in Boophilid ticks across continents based on morphological and genetic variations (García-García et al, 1999; de la Fuente et al, 2000; Ali et al, 2016; Lew-Tabor et al, 2017).…”

Characterization of Two Cuban Strains of Rhipicephalus Microplus Ticks

“…The hexagonal shaped basis capituli, the short anterior mouthparts with the hypostome longer than palps, the circular spiracular plates, the presence of accessory and adanal plates in males and the absence of anal groove and festoons in posterior body found on the Cuban strains are distinctive characteristics of the members inside this complex [9,12,19,20]. Signi cant differences found between female and male ticks con rmed remarkable dimorphism that exists between sexes in ticks which have been widely documented [21][22][23][24] and remains a valuable tool for tick taxonomic identi cation. For example, the caudal process observed in male specimens of the CC and ML strains allows differentiation from the R. annulatus species because this feature is absent in male ticks of that species [19].…”

Susceptibility of Rhipicephalus (Boophilus) microplus to fluazuron (2.5 mg/kg) and a combination of novaluron (2.0 mg/kg) + eprinomectin (0.36 mg/kg) in field studies in Brazil

“…(B.) microplus populations from Australia were recently reclassified as Rhipicephalus (Boophilus) australis (Estrada-Peña et al, 2012;Ali et al, 2016), which means that, probably, the tick species involved in the study of Bull et al (1996) is actually R. (B.)…”