Contents lists available at ScienceDirect Acta Tropica journal homepage: www.elsevier.com/locate/actatropica A checklist of the Anopheles mosquito species (Diptera: Culicidae) in Bhutan Rinzin Namgay a , Tobgyel Drukpa a , Tenzin Wangdi a , Dechen Pemo a , Ralph E. Harbach b , Pradya Somboon c, ⁎ a Vector-Borne Disease Control Programme, Ministry of Health, Gelephu, Bhutan b Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK c Center of Insect Vector Study, Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand ARTICLE INFO Keywords: Anopheles Bhutan ABSTRACT The present paper records, for the first time, the Anopheles fauna of Bhutan, determined from surveys conducted from 2007 to early 2018. Adult mosquitoes were collected mainly on cattle bait and occasionally in human landing catches. Collections of immature stages were performed in various aquatic habitats. Larvae were pre- served or reared to adults. Identification was based on morphological characters using available keys. A total of 30 species were identified, including nine species of subgenus Anopheles and 21 species of subgenus Cellia. Distribution and collection data are provided with notes on the locations and habitats of the species. Anopheles pseudowillmori is suspected to be a vector of malarial parasites in the plains and hilly forested areas of the country because it is widely distributed and the most common species collected in human landing catches. Notes also include observed morphological variation observed in An. baileyi and An. lindesayi, which differ from the type forms. Corrections are made for previous reports of Anopheles in Bhutan. The need for further surveys and molecular identification of members of species complexes and morphological variants is emphasized. 1. Introduction The Kingdom of Bhutan is a landlocked country situated in the Eastern Himalayan Mountains. It is located to the north of India and south of Tibet, lying between latitudes 26° and 29 °N and longitudes 88° and 93 °E. It is subdivided into 20 districts (Fig. 1), and Thimphu is the capital of the country. Bhutan has a population of about 800,000 people (United Nations, Department of Economic and Social Affairs, Population Division, 2017). Geographically, most of the land consists of steep and high mountains criss-crossed by a network of swift rivers, which form deep valleys before draining into the Indian plains in the south of the country. There are limited plains areas along the Indian border. Elevation rises from 100 m in the southern foothills to more than 7000 m in the north. The climate in Bhutan varies with elevation, from subtropical in the south to temperate in the highlands, and with polar-like climate in the north with snow throughout the year. Sixty percent of Bhutan consists of well-conserved forests with a great di- versity of plants and animals. Diseases caused by vector-borne patho- gens, including malaria, leishmaniasis, scrub typhus, dengue, chi- kungunya and Japanese encephalitis, occur in subtropical areas of the country (https://thebhutanese.bt/the-threat-of-vector-borne-diseases- in-bhutan/). Perennial malaria transmission in Bhutan occurs in seven of the 20 Dzongkhag (Districts) bordering India, i.e. the Samtse, Chhukha, Dagana, Sarpang, Zhemgang, Pemagatshel and Samdrup Jongkhar Districts (Tobgay et al., 2011). The malaria-endemic districts are mostly covered with forests, having a subtropical climate with hot and humid conditions and abundant rainfall during the monsoon period, which lasts up to three months (July to September). Four northern districts, Paro, Thimphu, Gasa and Bumthang, experience no malaria transmis- sion due to their higher elevation. The nine other districts experience seasonal transmission during the summer months. Plasmodium falci- parum and P. vivax are the main species of human malarial protozoa in Bhutan. Because there is no requirement for visas, movement of Indian and Bhutanese people across border areas is very common. Malaria control in the Indian border areas is relatively inadequate and malaria transmission is much more intense (Wangdi et al., 2015). People who travel into endemic areas in India may acquire malaria from the bites of local mosquito vectors, and Indian people infected with malaria may introduce the parasites to local people in Bhutan. Historically, malaria was a dreadful disease in Bhutan. According to a malaria survey conducted in 1962, malaria prevalence in children ranged from 10.7 to 55.5% in endemic villages (Vector-borne Disease Control Programme, 2007). The national malaria eradication https://doi.org/10.1016/j.actatropica.2018.09.006 Received 22 July 2018; Received in revised form 7 September 2018; Accepted 8 September 2018 ⁎ Corresponding author. E-mail address: pradya.somboon@cmu.ac.th (P. Somboon). Acta Tropica 188 (2018) 206–212 Available online 10 September 2018 0001-706X/ © 2018 Elsevier B.V. All rights reserved. T