On the taxonomy of chigger mites (Acariformes: Trombiculidae) parasitizing birds in Thailand and Malaysia, with the description of a new species Author K, Sirikamon Koosakulnirand Author RajasegaranK, Praveena Tropical Infectious Diseases Research and Education Centre, Universiti Malaya, Kuala Lumpur, & Institute for Advanced Studies, Universiti Malaya, Kuala Lumpur, Malaysia. Author Alkathiry K, Hadil A. Author ChaisiriK, Kittipong Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Author RoundK, Philip D. Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand. Author Eiamampai, Krairat Department of National Park Wildlife and Plant Conservation, Ministry of Natural Resources and Author Ahmad KhusainiK, Mohd K. S. Wildlife Conservation Division, Department of Wildlife and National Parks Peninsular Malaysia, Author RamjiK, Mohamad Fizl Sidq Faculty of Resources Science and Technology, University Malaysia Sarawak, Kota Samarahan, Sarawak, Author AbubakarK, Sazaly Tropical Infectious Diseases Research and Education Centre, Universiti Malaya, Kuala Lumpur, Author Ya’cobK, Zubaidah Tropical Infectious Diseases Research and Education Centre, Universiti Malaya, Kuala Lumpur, Author Stekolnikov K, Alexandr A. Laboratory of Parasitic Arthropods, Zoological Institute of the Russian Academy of Sciences, Saint Author Makepeace K, Benjamin L. Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK. text Acarologia 2023 2023-11-06 63 4 1109 1138 http://dx.doi.org/10.24349/yt89-g1ei journal article 10.24349/yt89-g1ei 2107-7207 10785781 Neacariscus ( Whartonacarus ) shiraii (Sasa, Kano & Obata, 1952) ( Figs 2F – G , 3B ) Diagnosis — SIF = 7BS-N-2-3111.1000; fPp = B/N/NNN; fCx = 1.1.1; fSt = 2.4; PL> AL ≥ AM (PL> AM> AL); fD = 2H-23-24(20)-18(19)-13(11)-(0 – 2); DS = 77 – 92; V = 85 – 98; NDV = 162 – 190; Ip = 1381 – 1550; eyes 2 + 2, very large; flagelliform sensilla (trichobothria) with few branches in distal part; sensillary bases anterior to level of PL; solenidion ω () of palpal tarsus long and slender; leg tarsi with multiple sclerite bars. Standard measurements are given in Table 3 . Distribution and hosts — This species was described from Tokyo ( Japan ), ex Pluvialis dominica (syn.: Charadrius dominicus ). Later it was recorded on Heron Isl. ( Australia , Queensland ), ex Limosa lapponica (L.) ( Charadriiformes : Scolopacidae ); on Guam , ex P. dominica ; on Okinawa Isl. ( Japan ), ex Sterna dougalli Montagu ( Charadriiformes : Laridae ); and in Mexico ( Sonora ), ex Haematopus palliatus Temminck ( Charadriiformes : Haematopodidae ) ( Vercammen-Grandjean & Langston 1976 ). Here it is for the first time recorded in Thailand and on Xenus cinereus . Material examined — Two larvae ( ZIN 17981, 17982) ex two Xenus cinereus , THAILAND , Trang province , Samran Beach, 7.209399°N , 99.557854°E , 19 March 2022 , coll. S. Koosakulnirand. Remarks — The form of N . ( W .) shiraii from Mexico , with DS = 44 and V = 44 ( Loomis 1966 ; Mertins et al. 2009 ), probably belongs to some other species.