ORIGINAL PAPER Phlebotomus (Euphlebotomus) mascomai n. sp. (Diptera–Psychodidae) Frédérique Muller & Jérôme Depaquit & Nicole Léger Received: 2 July 2007 / Accepted: 19 July 2007 # Springer-Verlag 2007 Abstract A new species of sandfly is described from limestone caves in Thailand. The inclusion of this species in the subgenus Euphlebotomus is justified on the basis of characters of the male genitalia (paramere, basal lobe). The male–female gathering in the same taxon is based on ecological (cavernicolous species), morphological (length of male genital filaments and female spermathecal ducts) and molecular (homology of cytochrome b mt DNA sequences) criteria. A differential diagnosis between Phlebotomus mascomai n. sp. and P. argentipes Annandale & Brunetti, the vector of Leishmania donovani (Laveran & Mesnil) in India, is proposed based on several morphological characters like antennal formula and genitalia. Introduction Nineteen species of phlebotomine sandflies have been recorded in Thailand (Apiwathnasorn et al. 1989, 1993). Two of them belong to the sub-genus Euphlebotomus Theodor 1948: Phlebotomus argentipes Annandale & Brunetti, the main vector of Leishmania donovani (Laveran & Mesnil) in India, and P. philippinensis gouldi Lewis, found in the rain forest of Thailand. P. argentipes, mostly anthropophilic in India, appears to be a cave-dweller in Thailand and in other west Asiatic country, sucking blood on bats and cattle. Such a variability in behaviour calls to mind the possibility for this bi-nomen to be a species complex (Lewis 1978). Description of a new species of Euphlebotomus found in Thailand caves thus offers the opportunity to discuss the status of this very variable species in spite of the limited number of autochtonous visceral leishmaniasis observed in Thailand (Thisyakorn et al. 1999). Materials and methods Type locality Thailand, province of Ratchabun, district of Muang, sub-district of Huay Phai, inside the cave “Khao Tham Khun Chom” (13°48’85,6’’N; 99°70’35,7’’E). Altitude: 35 m. above sea level. All the specimens were caught in February 2005 (Barbazan recoltavit) by CDC miniature light traps between 5 P.M. and 9 A.M. They were kept in 96° ethanol and mounted in toto for morphological study according to Abonnenc’ s method (1972): 4–8 h in 10% KOH solution followed by eight baths (20 min each) in water, then at least 1 h in Berlese’ s medium. Females were directly mounted in this liquid with their spermathecae dissected, then re- mounted in chloral gum when possible. Most of the males were dehydrated in ethanol of growing concentrations (from 70% to absolute ethanol) then in beech creosote and finally mounted in Canada balsam. Some specimens were prepared for both morphological and molecular studies. The selected gene was cytochrome b of the mtDNA, known to be informative at this taxonomic level. The head and genitalia of each sandfly were cut off in a drop of ethanol, cleared in boiling Marc–André solution, and mounted under a coverslip in gum chloral for identification. These slides are available upon request to the corresponding author. Genomic DNA was extracted Parasitol Res DOI 10.1007/s00436-007-0682-9 F. Muller : J. Depaquit (*) Laboratoire de Parasitologie–EA 3800, Faculté de Pharmacie, 51, rue Cognacq-Jay, 51096 Reims cedex, France e-mail: jerome.depaquit@univ-reims.fr N. Léger 63, avenue Pierre Sémard, La Varenne Saint Hilaire, France