Rhipicephalus microplus (Canestrini, 1888) Studies are urgently needed to determine whether this is a species complex (Estrada-Peña et al. 2012). Recently, Roy et al. (2018) showed that the complex contains at least 5 taxa including R. annulatus, R. australis, and R. microplus clades A-C, with ticks from Bangladesh, Pakistan and Myanmar being assigned to clade C. These authors stress the high level of morphological variation present in these taxa and indicate that additional morphological, genomic and cross-breeding studies are needed to determine species status. Rhipicephalus microplus is a cattle parasite with a one-host life cycle. It is thought to have originated in the Indian subregion but has been introduced into many parts of the world, including other parts of Asia, with its hosts (Hoogstraal 1985b). It was previously placed in the genus Boophilus until this was reduced to a subgenus within Rhipicephalus (Beati and Keirans 2001; Murrell and Barker 2003). An attempt to clarify the taxonomic situation in the subgenus Boophilus (Hoogstraal 1956) showed that the Asian species had been variously referred to as B. annulatus, B. annulatus var. australis, B. australis, B. distans, B. krigjsmani, B. longiscutatus and B. rotundiscutatus (at the time Boophilus had generic status; Minning 1934; Anastos 1950). Estrada-Peña et al. (2012) showed that R. australis is a good species known to be present in Australia, New Caledonia, Borneo, the Philippines, Sumatra, Java, New Guinea, Cambodia, and Tahiti. It is possible that R. australis and R. microplus may both be found sympatrically in Southeast Asia, although evidence for this is not available. Rhipicephalus microplus sensu lato is the most common cattle tick in continental Southeast Asia, occurring throughout the region wherever cattle are found, although it can also occur on other domestic stock (Rajamanikan 1968; Petney and Keirans 1996b). The record of Kolonin (1995) from banteng (Bos javanicus) in an area of virgin forest in Vietnam well away from settlements should be further investigated to determine its validity. In continental Southeast Asia R. microplus occurs in Cambodia, Lao PDR, peninsular Malaysia, Myanmar, Thailand and Vietnam (Petney and Keirans 1996b). All life history stages are illustrated in Yamaguti et al. (1971).

Published as part of Petney, Trevor N., Boulanger, Nathalie, Saijuntha, Weerachai, Chitimia-Dobler, Lidia, Pfeffer, Martin, Eamudomkarn, Chatanun, Andrews, Ross H., Ahamad, Mariana, Putthasorn, Noppadon, Muders, Senta V., Petney, David A. & Robbins, Richard G., 2019, Ticks (Argasidae, Ixodidae) and tick-borne diseases of continental Southeast Asia, pp. 1-89 in Zootaxa 4558 (1) on page 35, DOI: 10.11646/zootaxa.4558.1.1, http://zenodo.org/record/2613120