Unexpected diversity of sandflies (Diptera: Psychodidae) in tourist caves in Northern Thailand

Abstract

Certain species of Phlebotomine sandflies (Diptera: Psychodidae) are vectors of the protozoa which causes leishmaniasis. Sandflies are found breeding in enclosed places like caves. Thailand is a popular tourist destination, including for ecotourism activities like caving, which increases the risk of contact between tourists and sandflies. Surveillance of sandflies is important for monitoring this risk but identification of species based on morphology is challenged by phenotypic plasticity and cryptic diversity. DNA barcodes have been used for the identification of sandflies in Thailand. We collected sandflies using CDC light trap from four tourist caves in Northern Thailand. Female sandflies were provisionally sorted into 13 morphospecies and 19 unidentified specimens. DNA was extracted from the thorax and legs of sandflies and the DNA barcode region of cytochrome c oxidase I mtDNA amplified and sequenced. The specimens were sorted into 22 molecular operational taxonomic units (MOTU) based on the 145 DNA barcodes, which is significantly more than the morphospecies. Several of the taxa thought to be present in multiple caves, based on morphospecies sorting, split into cave-specific MOTU which likely represent cryptic species. Several MOTU reported in an earlier study from Wihan Cave, Thailand, were also found in these caves. This supports the use of DNA barcodes to investigate species diversity of sandflies and their useful role in surveillance of sandflies in Thailand.

Keywords:

• COI gene
• DNA barcoding
• sandflies
• species identification

Acknowledgements

The Department of National Parks, Wildlife, and Plant Conservation (Thailand) provided permission to conduct fieldwork at Chao Ram Cave (Sukhothai), Erawan Cave (Phrae), Yai Phatang Cave (Phayao) and Phadang Cave (Phitsanulok). Various colleagues at the Museum of Zoology, University of Malaya provided laboratory support.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding

Field trip expenses were supported by Naresuan University Research Fund to RP. DNA barcoding expenses were supported by the University of Malaya through grant RP003D-13SUS to JJW. Naresuan University provided a scholarship to JS to undertake an internship at the University of Malaya. The funding agents had no role in study design, analysis and writing the article.