On the taxonomy of chigger mites (Acariformes: Trombiculidae) parasitizing birds in Thailand and Malaysia, with the description of a new species

Abstract

Chigger mites were collected from 65 bird species in different regions of Thailand and Malaysia. In total, 21 species were recorded. The previously unknown fauna of chiggers parasitizing shorebirds of Thailand included one new species, Neacariscus (Whartonacarus) andamanensis n. sp. as well as Neacariscus (Neacariscus) pluvius (Wharton, 1945) previously recorded only in Oceania; Neacariscus (Whartonacarus) shiraii (Sasa, Kano and Obata, 1952) (known from Oceania and Japan); and Neacariscus (Whartonacarus) sulae (Oudemans, 1910) and Schoengastia archaea (Taufflieb, 1960), both described from West Africa. Toritrombicula kirhocephales Goff, 1982 described from Papua New Guinea was for the first time recorded in Asia (Thailand). Neoschoengastia gallinarum (Hatori, 1920) and Helenicula comata (Womersley, 1952) were for the first time recorded in Thailand. Ascoschoengastia lorius (Gunther, 1939) was for the first time recorded in Malaysia. Finally, Ericotrombidium cosmetopode (Vercammen-Grandjean and Langston, 1971) described from free larvae, was for the first time recorded on a host (bird Pellorneum ruficeps Swainson); and Leptotrombidium miculum (Traub and Audy, 1954) was for the first time recorded on a bird host. New host species were recorded for a large part of the collected chigger species.

Multi-Locus Sequence Analysis Indicates Potential Cryptic Speciation in the Chigger Mite Neoschoengastia gallinarum (Hatori, 1920) Parasitising Birds in Asia

“…The collection of N. gallinarum from both domestic and wild birds in various habitats in Peninsular Malaysia (e.g., forests, sanctuaries, and villages) may have contributed to greater genetic diversity in comparison to only one ecotype (villages) from Thailand, but broader sampling in Thailand will be required to unravel the potential impacts of environmental and host factors. In Peninsular Malaysia, N. gallinarum infested a wide range of bird host species, with L. rufa (Malayan crested fireback) and P. inopinatum (Mountain peacock-pheasant) noted as new host records [ 29 ] for this chigger species. Due to their decreasing population trends, L. rufa , P. inopinatum , and P. malacense (Malayan peacock-pheasant) are categorised as totally protected species in Malaysia [ 96 ] and classed as either “vulnerable” ( L. rufa , P. inopinatum ) or “endangered” ( P. malacense ) by the International Union for Conservation of Nature [ 97 , 98 , 99 , 100 ].…”

“…The recovered chiggers were stored in 70% ethanol at −20 • C. Chiggers from each host were counted and 10% of specimens were selected for mounting in Berlese fluid for species-level identification using an Axio Imager M2 microscope (Zeiss, Oberkochen, Germany) and ZEN 2011 imaging software [31]. These individuals were not used for DNA extraction but were retained as voucher specimens and deposited at the Tick Cell Biobank Asia Outposts Laboratory, Tropical Infectious Diseases Research & Education Centre, Universiti Malaya [29]. The remaining chiggers from each bird host were identified using the autofluorescence method [31] on a GXM-L3201 LED research fluorescence trinocular microscope (GT Vision LTD, Newmarket, UK) with reference to the voucher specimens.…”

“…are significant pests of domestic fowl, especially for turkeys in North America [ Neoschoengastia americana (Hirst, 1921)], common pheasants in Japan ( Neoschoengastia shiraii Sasa and Sato, 1953), and chickens in East and Southeast Asia ( Neoschoengastia gallinarum ) [ 26 , 27 , 28 ]. Recently, N. gallinarum was recorded for the first time in Thailand (parasitising domestic chickens), as well as being found in abundance on wild Galliformes [ Gallus gallus (Linnaeus, 1758) , Lophura rufa (Raffles, 1822), Polyplectron inopinatum (Rothschild, 1903), and Polyplectron malacense (Scopoli, 1786)] in Peninsular Malaysia [ 29 ]. China, Taiwan, and Vietnam are also included in this species’ range [ 23 ], which is widespread and greatly reduces the economic value of poultry due to damage to the carcass [ 28 ].…”