taxonID	type	description	language	source
03F987ECFFB5FFCD7EF1F9A57AC10E99.taxon	description	Figs 13, 22, 25, 30. Distribution: Afrotropical: Kenya, Madagascar, Mascarenes (La Réunion *, Mauritius *, Rodrigues *), Mozambique, Seychelles (Aldabra, Anonyme, Cosmoledo, Long, Mahé). Oriental: Chagos. Material examined (all “ A. H. Kirk-Spriggs & B. S. Muller, sweeping intertidal zone and coastal vegetation ”, unless otherwise stated). La Réunion: 5 ♀, St. - Paul, beach, 20 ° 58 ′ 15 ″ S, 55 ° 16 ′ 56 ″ E, 0 – 5 m, 21. x. 2015, A. H. Kirk Spriggs, sweeping intertidal zone (2 ♀ deposited LMC); 1 ♀, St. - Pierre, Pointe de Pont, 21 ° 20 ′ 51 ″ S, 55 ° 28 ′ 52 ″ E, 0 – 6 m, 13. xi. 2015, A. H. Kirk Spriggs, sweeping intertidal rocks and coral beach; 1 ♀, Pointe de Tremblet, 21 ° 17 ′ 34 ″ S, 55 ° 48 ′ 21 ″ E, 0 – 9 m, 9. xi. 2015, M. J. Ebejer, general sweeping; intertidal zone & sandy beach (deposited MJEC). Mauritius: 3 ♀, Black River, Le Morne Brabant, 20 ° 27 ′ 32 ″ S, 57 ° 19 ′ 42 ″ E, 1 – 3 m, 28. i. 2018; 4 ♂, 3 ♀, Black River, Tamarin, 20 ° 19 ′ 41 ″ S, 57 ° 22 ′ 33 ″ E, 1 – 3 m, 28. i. 2018; 2 ♂, 3 ♀, Flacq, Poste Lafayette, 20 ° 07 ′ 02 ″ S, 57 ° 45 ′ 05 ″ E, 1 – 3 m, 30. i. 2018; 1 ♀, Flacq, Troud’Eau Douce, 20 ° 14 ′ 20 ″ S, 57 ° 47 ′ 34 ″ E, 1 – 3 m, 27. i. 2018; 1 ♀, Grand Port, Grand Sable, 20 ° 19 ′ 12 ″ S, 57 ° 46 ′ 12 ″ E, 1 – 3 m, 27. i. 2018; 6 ♂, 12 ♀, Pamplemousses, Le Goulet, 20 ° 06 ′ 14 ″ S, 57 ° 31 ′ 02 ″ E, 1 – 3 m, 30. i. 2018 (1 ♂, 1 ♀ deposited LMC); 1 ♂, Pamplemousses, Tombeau Bay, 20 ° 08 ′ 00 ″ S, 57 ° 29 ′ 54 ″ E, 1 – 3 m, 30. i. 2018; 1 ♀, Pamplemousses, Trou aux Biches, 20 ° 02 ′ 36 ″ S, 57 ° 32 ′ 14 ″ E, 1 – 3 m, 29 – 30. i. 2018; 1 ♀, Rivière du Rempart, Bain Boeuf, 19 ° 59 ′ 13 ″ S, 57 ° 36 ′ 12 ″ E, 1 – 3 m, 30. i. 2018; 2 ♀, Rivière du Rempart, Grand Gaube, 20 ° 01 ′ 00 ″ S, 57 ° 40 ′ 55 ″ E, 1 – 3 m, 29 – 30. i. 2018; 1 ♀ (cf.), Savanne, Bel Ombre, 20 ° 29 ′ 32 ″ S, 57 ° 22 ′ 42 ″ E, 1 – 3 m, 26. i. 2018; 2 ♀, Savanne, Riambel, 20 ° 31 ′ 09 ″ S, 57 ° 30 ′ 25 ″ E, 1 – 3 m, 26. i. 2018; 6 ♂, 6 ♀, Savanne, Rivière des Galets, 20 ° 30 ′ 04 ″ S, 57 ° 26 ′ 52 ″ E, 1 – 3 m, 26. i. 2018 (1 ♂ deposited LMC). Rodrigues: 1 ♂, 2 ♀, Anse Ally, 19 ° 41 ′ 42 ″ S, 63 ° 29 ′ 48 ″ E, 1 – 3 m, 10. ii. 2018; 2 ♂, 1 ♀, Anse Mourouk, 19 ° 44 ′ 23 ″ S, 63 ° 27 ′ 53 ″ E, 1 – 3 m, 10. ii. 2018; 2 ♂, 4 ♀, Plaine Corail, 19 ° 46 ′ 05 ″ S, 63 ° 22 ′ 36 ″ E, 1 – 3 m, 9. ii. 2018 (1 ♂, 1 ♀ deposited LMC); 2 ♂, 2 ♀, Rivière Banane, 19 ° 40 ′ 37 ″ S, 63 ° 28 ′ 30 ″ E, 1 – 3 m, 10. ii. 2018 (1 ♂ deposited LMC) (all deposited BMSA, unless otherwise stated). Comments: Originally described from Seychelles, this delicate, pale yellow beach fly was later recorded from the central-eastern coast of the Afrotropical Region, including Madagascar (Munari & Mathis 2010) and from the remote Chagos Islands to the east (Munari 2015). The species is recorded herein for the first time from the Mascarenes. Afrotethina aurisetulosa belongs to an endemic Afrotropical genus, which includes eight species of which A. martinezi Munari, 2005 is known so far exclusively from the southern Arabian Peninsula.	en	Munari, Lorenzo, Kirk-Spriggs, Ashley H., Mcgregor, Gillian K. (2020): The beach flies of the Mascarene Islands (Diptera: Canacidae: Tethininae). Zootaxa 4853 (2): 183-198, DOI: 10.11646/zootaxa.4853.2.2
03F987ECFFB4FFC37EF1F9E17D3C0D75.taxon	description	Figs 11, 18, 23, 26, 31. Distribution. Afrotropical: Kenya, Madagascar, Mascarenes (Mauritius *, Réunion *, Rodrigues *), Oman, Seychelles (Aldabra, Anonyme, Aride, Astove, Long, Mahé,? Praslin), Tanzania, United Arab Emirates. Australasian / Oceanian: Australia (Queensland), Caroline Islands (Yap), Mariana Islands (Guam, Saipan), Palau, Papua New Guinea. Oriental: China (Hong Kong - Lantau), Malaysia (Sabah, Singapore), Philippines (Balabac, Busuanga, Calicoan, Culion, Leyte, Masbate, Mindanao, Negros Oriental, Palawan), Singapore. Palaearctic: Qatar, Saudi Arabia. South Indian Ocean Islands: Amsterdam Island. Material examined (all “ A. H. Kirk-Spriggs & B. S. Muller, sweeping intertidal zone and coastal vegetation ”, unless otherwise stated). La Réunion: 4 ♂, 1 ♀, Pointe de Tremblet, 21 ° 17 ′ 34 ″ S, 55 ° 48 ′ 21 ″ E, 0 – 9 m, 9. xi. 2015, M. J. Ebejer, general sweeping; intertidal zone & sandy beach (deposited MJEC). Mauritius: 23 ♂, 17 ♀, Black River, Le Morne Brabant, 20 ° 27 ′ 32 ″ S, 57 ° 19 ′ 42 ″ E, 1 – 3 m, 28. i. 2018 (1 ♂ deposited LMC); 5 ♂, 4 ♀, Black River, Petite Case Noyale, 20 ° 24 ′ 23 ″ S, 57 ° 22 ′ 10 ″ E, 1 – 3 m, 28. i. 2018 (2 ♂, 1 ♀ deposited LMC); 1 ♀, Flacq, Poste de Flacq, 20 ° 09 ′ 40 ″ S, 57 ° 44 ′ 49 ″ E, 1 – 3 m, 26. i. 2018; 2 ♂, Flacq, Poste Lafayette, 20 ° 07 ′ 02 ″ S, 57 ° 45 ′ 05 ″ E, 1 – 3 m, 30. i. 2018; 60 ♂, 86 ♀, Grand Port, Grand Sable, 20 ° 19 ′ 12 ″ S, 57 ° 46 ′ 12 ″ E, 1 – 3 m, 27. i. 2018 (2 ♀ deposited LMC); 2 ♀, Grand Port, Pointe d’Esny, 20 ° 25 ′ 28 ″ S, 57 ° 43 ′ 22 ″ E, 1 – 3 m, 27. i. 2018; 50 ♂, 56 ♀, Pamplemousses, Le Goulet, 20 ° 06 ′ 14 ″ S, 57 ° 31 ′ 02 ″ E, 1 – 3 m, 30. i. 2018 (1 ♂, 1 ♀ deposited LMC); 3 ♂, Pamplemousses, Trou aux Biches, 20 ° 02 ′ 36 ″ S, 57 ° 32 ′ 14 ″ E, 1 – 3 m, 29 – 30. i. 2018; 1 ♂, 4 ♀, Rivière du Rempart, Grand Gaube, 20 ° 01 ′ 00 ″ S, 57 ° 40 ′ 55 ″ E, 1 – 3 m, 29 – 31. i. 2018; 1 ♀ (cf.), Rivière du Rempart, Pointe des Lascars, 20 ° 05 ′ 14 ″ S, 57 ° 42 ′ 26 ″ E, 1 – 3 m, 31. i. 2018; 2 ♂, 6 ♀, Savanne, Bel Ombre, 20 ° 30 ′ 00 ″ S, 57 ° 23 ′ 34 ″ E, 1 m, 11. xii. 2016, sweeping coastal rocks and sandy beach. Rodrigues: 1 ♂, Anse aux Anglais, 19 ° 40 ′ 15 ″ S, 63 ° 26 ′ 19 ″ E, 1 – 3 m, 10. ii. 2018; 1 ♂, Baie du Nord, 19 ° 42 ′ 33 ″ S, 63 ° 22 ′ 20 ″ E, 1 – 3 m, 9. ii. 2018; 1 ♂, 4 ♀, Petite Gravier, 19 ° 43 ′ 40 ″ S, 63 ° 29 ′ 03 ″ E, 1 – 3 m, 10. ii. 2018 (1 ♂ deposited LMC); 3 ♂, 5 ♀, Plaine Corail, 19 ° 46 ′ 05 ″ S, 63 ° 22 ′ 36 ″ E, 1 – 3 m, 9. ii. 2018 (all deposited BMSA, unless otherwise stated). Comments: A rather common Indo-Pacific species, characterised primarily by the peculiar chaetotaxy pattern of the posteroventral armature of the male mid femur (see above identification key and Fig. 11). Additionally, the morphological form of the external male terminalia is also distinctly dissimilar from that of the other two Mascarenian species of Dasyrhicnoessa (compare Fig. 18 with Figs 16, 17). In fact, D. insularis (Aldrich, 1931) and D. vockerothi Hardy & Delfinado, 1980, share a similar structure of the surstyli with each other (Figs 16, 17), so much so, that they can be assigned, along with a few other Pacific species, to a thus far unnamed species-group. Dasyrhicnoessa ferruginea is newly recorded here from the Mascarenes.	en	Munari, Lorenzo, Kirk-Spriggs, Ashley H., Mcgregor, Gillian K. (2020): The beach flies of the Mascarene Islands (Diptera: Canacidae: Tethininae). Zootaxa 4853 (2): 183-198, DOI: 10.11646/zootaxa.4853.2.2
03F987ECFFBAFFC07EF1FAAA7C5F085D.taxon	description	Figs 10, 16, 24, 27, 32. Distribution. Afrotropical: Cameroon, Madagascar, Mascarenes (La Réunion *, Mauritius *, Rodrigues *), Nigeria, Seychelles (Mahé), Sierra Leone. Australasian / Oceanian: American Samoa (Tutuila), Australia (Queensland), Austral Islands, Bismarck Islands (Dyaul), Canton Island, Caroline Islands (Ponhpei, Chuuk, Yap, Palau), Fiji Islands (Ovalau, Suva, Vanua Balavu, Viti Levu),? French Polynesia (Society Islands: Moorea), Hawaii (French Frigate Shoals, Hawaii, Hilo, Kahoolawe, Kauai, Lisiansky, Maui, Midway Atoll, Molokai, Oahu, Pearl and Hermes Reef), Kiribati (Butaritari, Makin, Eita, Tarawa, Abemama), Line Islands (Christmas), Mariana Islands (Saipan, Tinian), Marquesas (Hivaoa, Nuku Hiva), Marshall Islands (Majuro, Japtan, Parry, Lib, Jibu, Jaluit, Namorik), Palmyra Island, Pitcairn Island, Rapa Island, Society Islands (Bora Bora, Raiatea, Tahiti), Vanuatu (Erromanga, Aneityum), Wake Island. Nearctic: Bermuda, United States (Florida). Neotropical: Bahamas (South Bimini), Belize, Brazil (Ceará, Paraná, São Paulo), Mexico (Tabasco), West Indies (Cuba, Dominica, St. Kitts, St. Lucia, St. Vincent). Oriental: Chagos, Indonesia (Sulawesi, Ternate). Material examined (all “ A. H. Kirk-Spriggs & B. S. Muller, sweeping intertidal zone and coastal vegetation ”, unless otherwise stated). La Réunion: 1 ♀, Grande Anse, 21 ° 22 ′ 17 ″ S, 55 ° 33 ′ 00 ″ E, 26. x. 2015, 0 – 12 m, M. J. Ebejer, general sweeping; secondary forest, intertidal rocks & coral beach (deposited MJEC); 1 ♂, St. - Louis, Rivière St. - Étienne, 21 ° 17 ′ 54 ″ S, 55 ° 24 ′ 07 ″ E, 0 – 9 m, 18. x. 2015, M. J. Ebejer, general sweeping; intertidal rocks & vegetated gravel plain (deposited MJEC); 1 ♀, St. - Pierre, Pointe de Pont, 21 ° 20 ′ 51 ″ S, 55 ° 28 ′ 52 ″ E, 0 – 6 m, sweeping intertidal rocks and coral beach, 13. xi. 2015, A. H. Kirk Spriggs. Mauritius: 14 ♂, 11 ♀, Black River, Le Morne Brabant, 20 ° 27 ′ 32 ″ S, 57 ° 19 ′ 42 ″ E, 1 – 3 m, 28. i. 2018 (1 ♀ deposited LMC); 63 ♂, 35 ♀, Black River, Petite Case Noyale, 20 ° 24 ′ 23 ″ S, 57 ° 22 ′ 10 ″ E, 1 – 3 m, 28. i. 2018 (2 ♂ deposited LMC); 3 ♂, 4 ♀, Black River, Tamarin, 20 ° 19 ′ 41 ″ S, 57 ° 22 ′ 33 ″ E, 1 – 3 m, 28. i. 2018; 23 ♂, 86 ♀, Grand Port, Grand Sable, 20 ° 19 ′ 12 ″ S, 57 ° 46 ′ 12 ″ E, 1 – 3 m, 27. i. 2018 (2 ♂, 1 ♀ deposited LMC); 8 ♂, 8 ♀, Grand Port, Pointe d’Esny, 20 ° 25 ′ 28 ″ S, 57 ° 43 ′ 22 ″ E, 1 – 3 m, 27. i. 2018 (1 ♀ deposited LMC); 4 ♂, 4 ♀, Grand Port, Vieux Grand Port, 20 ° 22 ′ 23 ″ S, 57 ° 42 ′ 48 ″ E, 1 – 3 m, 27. i. 2018 (1 ♂ deposited LMC); 4 ♂, 1 ♀, Pamplemousses, Le Goulet, 20 ° 06 ′ 14 ″ S, 57 ° 31 ′ 02 ″ E, 1 – 3 m, 30. i. 2018; 9 ♂, 12 ♀, Pamplemousses, Tombeau Bay, 20 ° 08 ′ 00 ″ S, 57 ° 29 ′ 54 ″ E, 1 – 3 m, 30. i. 2018 (1 ♀ deposited LMC); 2 ♀, Pamplemousses, Trou aux Biches, 20 ° 02 ′ 36 ″ S, 57 ° 32 ′ 14 ″ E, 1 – 3 m, 29 – 30. i. 2018; 2 ♂, 6 ♀, Rivière du Rempart, Pointe des Lascars, 20 ° 05 ′ 14 ″ S, 57 ° 42 ′ 26 ″ E, 1 – 3 m, 31. i. 2018; 5 ♂, 3 ♀, Savanne, Bel Ombre, 20 ° 30 ′ 00 ″ S, 57 ° 23 ′ 34 ″ E, 1 m, sweeping coastal rocks and sandy beach, 11. xii. 2016 (1 ♂ deposited LMC); 3 ♂, 2 ♀, Savanne, Bel Ombre, 20 ° 29 ′ 32 ″ S, 57 ° 22 ′ 42 ″ E, 1 – 3 m, 26. i. 2018; 2 ♀, Savanne, Riambel, 20 ° 31 ′ 09 ″ S, 57 ° 30 ′ 25 ″ E, 1 – 3 m, 26. i. 2018. Rodrigues: 2 ♂, 2 ♀, Anse aux Anglais, 19 ° 40 ′ 15 ″ S, 63 ° 26 ′ 19 ″ E, 1 – 3 m, 10. ii. 2018 (1 ♂, 1 ♀ deposited LMC); 2 ♀, Anse Mourouk, 19 ° 44 ′ 23 ″ S, 63 ° 27 ′ 53 ″ E, 1 – 3 m, 10. ii. 2018; 15 ♂, 11 ♀, Baie du Nord, 19 ° 42 ′ 33 ″ S, 63 ° 22 ′ 20 ″ E, 1 – 3 m, 9. ii. 2018 (1 ♀ deposited LMC); 1 ♀, Île Michel, 19 ° 44 ′ 43 ″ S, 63 ° 24 ′ 13 ″ E, 1 – 3 m, 10. ii. 2018; 2 ♀, Plaine Corail, 19 ° 46 ′ 05 ″ S, 63 ° 22 ′ 36 ″ E, 1 – 3 m, 9. ii. 2018 (all deposited BMSA, unless otherwise stated). Comments: A common pantropical beach fly. In this species the colour of the thorax often exhibits strong variation. The following range of variation has been observed in specimens from different world sites: mesonotum entirely yellow to blackish, sometimes scutum dark brown and scutellum yellow only at margin; in a few cases, scutum dark brown and scutellum predominantly yellow. Though rather infrequent, some transitional forms occur in formerly studied specimens (Munari 2002). The above is not corroborated by the material from the Mascarenes, which does not exhibit significant variation in mesonotal colour, the yellow or sometimes yellowish fulvous colours being invariably present, to a greater or lesser extent on the scutum. Similar to other Indo-Pacific congeners, the posteroventral armature of the male mid femur is formed of a long row of regular, spine-like setae, gently decreasing in size towards the apex of the femur.	en	Munari, Lorenzo, Kirk-Spriggs, Ashley H., Mcgregor, Gillian K. (2020): The beach flies of the Mascarene Islands (Diptera: Canacidae: Tethininae). Zootaxa 4853 (2): 183-198, DOI: 10.11646/zootaxa.4853.2.2
03F987ECFFB9FFC17EF1FB507A870DE1.taxon	description	Figs 12, 17, 28, 33. Distribution. Afrotropical: Mascarenes (Mauritius *, Rodrigues *), Seychelles (Aldabra, Astove, Mahé). Australasian / Oceanian: Australia (New South Wales, Northern Territory, Queensland), Bismarck Islands (Dyaul), Caroline Islands (Truk, Palau), Hawaii (Hawaii, Hilo, Kauai, Maui, Molokai, Oahu), Kiribati, Mariana Islands (Guam, Saipan), Marshall Islands,? New Caledonia, Papua New Guinea, Wake Island. Oriental: Cocos Islands, Japan (Ryukyu Islands), Malaysia (Penang, Sarawak, Selangor), Philippines, Singapore, Sri Lanka. Material examined (all “ A. H. Kirk-Spriggs & B. S. Muller, sweeping intertidal zone and coastal vegetation ”, unless otherwise stated). Mauritius: 2 ♂, 1 ♀, Flacq, Poste Lafayette, 20 ° 07 ′ 02 ″ S, 57 ° 45 ′ 05 ″ E, 1 – 3 m, 30. i. 2018 (1 ♂ deposited LMC); 1 ♀ (cf.), Pamplemousses, Le Goulet, 20 ° 06 ′ 14 ″ S, 57 ° 31 ′ 02 ″ E, 1 – 3 m, 30. i. 2018; 1 ♂, 2 ♀, Pamplemousses, Trou aux Biches, 20 ° 02 ′ 36 ″ S, 57 ° 32 ′ 14 ″ E, 1 – 3 m, 29 – 30. i. 2018; 1 ♀, Savanne, Bel Ombre, 20 ° 29 ′ 32 ″ S, 57 ° 22 ′ 42 ″ E, 1 – 3 m, 26. i. 2018; 1 ♂, Savanne, Riambel, 20 ° 31 ′ 09 ″ S, 57 ° 30 ′ 25 ″ E, 1 – 3 m, 26. i. 2018; 1 ♂, 1 ♀, Savanne, Rivière des Galets, 20 ° 30 ′ 04 ″ S, 57 ° 26 ′ 52 ″ E, 1 – 3 m, 26. i. 2018. Rodrigues: 2 ♂, 1 ♀, Anse Ally, 19 ° 41 ′ 42 ″ S, 63 ° 29 ′ 48 ″ E, 1 – 3 m, 10. ii. 2018; 1 ♂, 2 ♀, Anse aux Anglais, 19 ° 40 ′ 15 ″ S, 63 ° 26 ′ 19 ″ E, 1 – 3 m, 10. ii. 2018 (1 ♂ deposited LMC); 1 ♂, Anse Mourouk, 19 ° 44 ′ 23 ″ S, 63 ° 27 ′ 53 ″ E, 1 – 3 m, 10. ii. 2018 (deposited LMC); 3 ♀ (cf.), Baie du Nord, 19 ° 42 ′ 33 ″ S, 63 ° 22 ′ 20 ″ E, 1 – 3 m, 9. ii. 2018 (1 ♀ deposited LMC); 2 ♀, Île Michel, 19 ° 44 ′ 43 ″ S, 63 ° 24 ′ 13 ″ E, 1 – 3 m, 10. ii. 2018; 1 ♂, Plaine Mapou, 19 ° 44 ′ 52 ″ S, 63 ° 20 ′ 21 ″ E, 1 – 3 m, 9. ii. 2018; 3 ♂, Rivière Banane, 19 ° 40 ′ 37 ″ S, 63 ° 28 ′ 30 ″ E, 1 – 3 m, 10. ii. 2018 (all deposited BMSA, unless otherwise stated). Comments: Usually smaller than its congener, D. insularis, with which it is easily confused by the moderate to wide coverage of yellow on the mesonotum, which in some cases, may be uniformly pale grey, with light yellowish nuances. Specimens from different Pacific locations often exhibit the same range of variation, with a few even exhibiting a uniformly grey to brownish mesonotum. The posteroventral armature of spine-like setae on the male mid femur is also similar in the two species and most specimens have this armature similar to that of D. insularis. As well as their relative sizes, the two species are unequivocally characterised by the morphology of the male terminalia, especially the shape of the surstylus (Figs 16, 17). Conversely, females are only tentatively identified if strictly associated with males from the same locality. Based on the plentiful material examined here, it is concluded that D. vockerothi occurs infrequently in the Mascarenes, or at least on the beaches where the fly material was sampled, despite the wide distribution of this species on the seashores of the Oriental and Australasian / Oceanian Regions. These records, from the western Indian Ocean, represent the western-most occurrence of this prevalently Pacific Ocean species. Dasyrhicnoessa vockerothi is recorded here for the first time from the Mascarenes.	en	Munari, Lorenzo, Kirk-Spriggs, Ashley H., Mcgregor, Gillian K. (2020): The beach flies of the Mascarene Islands (Diptera: Canacidae: Tethininae). Zootaxa 4853 (2): 183-198, DOI: 10.11646/zootaxa.4853.2.2
03F987ECFFB8FFC17EF1F8FD7C940B92.taxon	materials_examined	Material examined: 1 ♀, Mauritius: Black River, Petite Case Noyale, 20 ° 24 ′ 23 ″ S, 57 ° 22 ′ 10 ″ E, 1 – 3 m, 28. i. 2018, A. H. Kirk-Spriggs & B. S. Muller, sweeping intertidal zone and coastal vegetation (deposited BMSA). Comments: A single female specimen, with a distinctly narrow gena and moderately depressed head. This specimen cannot currently be assigned to a given specific taxon.	en	Munari, Lorenzo, Kirk-Spriggs, Ashley H., Mcgregor, Gillian K. (2020): The beach flies of the Mascarene Islands (Diptera: Canacidae: Tethininae). Zootaxa 4853 (2): 183-198, DOI: 10.11646/zootaxa.4853.2.2
03F987ECFFBFFFC47EF1FAE97DFE0D29.taxon	description	Figs 14, 29, 34. Distribution. Afrotropical: Mascarenes (Mauritius, Rodrigues *), Seychelles (Cousine, Mahé). Oriental: India (Goa), Maldives, Sri Lanka. Material examined (all “ A. H. Kirk-Spriggs & B. S. Muller, sweeping intertidal zone and coastal vegetation ”, unless otherwise stated). Mauritius: 1 ♀, Black River, Albion, 20 ° 12 ′ 35 ″ S, 57 ° 24 ′ 13 ″ E, 1 – 3 m, 28. i. 2018; 1 ♀, Black River, Petite Case Noyale, 20 ° 24 ′ 23 ″ S, 57 ° 22 ′ 10 ″ E, 1 – 3 m, 28. i. 2018; 45 ♂, 38 ♀, Black River, Tamarin, 20 ° 19 ′ 41 ″ S, 57 ° 22 ′ 33 ″ E, 1 – 3 m, 28. i. 2018 (1 ♂, 3 ♀ deposited LMC); 4 ♂, 1 ♀, Flacq, Poste Lafayette, 20 ° 07 ′ 02 ″ S, 57 ° 45 ′ 05 ″ E, 1 – 3 m, 30. i. 2018 (1 ♂ deposited LMC); 3 ♂, 6 ♀, Flacq, Trou d’Eau Douce, 20 ° 14 ′ 20 ″ S, 57 ° 47 ′ 34 ″ E, 1 – 3 m, 27. i. 2018; 53 ♂, 111 ♀, Pamplemousses, Le Goulet, 20 ° 06 ′ 14 ″ S, 57 ° 31 ′ 02 ″ E, 1 – 3 m, 30. i. 2018 (1 ♂ deposited LMC); 16 ♂, 22 ♀, Pamplemousses, Tombeau Bay, 20 ° 08 ′ 00 ″ S, 57 ° 29 ′ 54 ″ E, 1 – 3 m, 30. i. 2018 (1 ♂ deposited LMC); 5 ♂, 4 ♀, Pamplemousses, Trou aux Biches, 20 ° 02 ′ 36 ″ S, 57 ° 32 ′ 14 ″ E, 1 – 3 m, 29 – 30. i. 2018; 28 ♂, 23 ♀, Rivière du Rempart, Bain Boeuf, 19 ° 59 ′ 13 ″ S, 57 ° 36 ′ 12 ″ E, 1 – 3 m, 30. i. 2018 (1 ♀ deposited LMC); 1 ♂, Rivière du Rempart, Grand Gaube, 20 ° 01 ′ 00 ″ S, 57 ° 40 ′ 55 ″ E, 1 – 3 m, 29 – 30. i. 2018; 4 ♂, 1 ♀, Rivière du Rempart, Pointe des Lascars, 20 ° 05 ′ 14 ″ S, 57 ° 42 ′ 26 ″ E, 1 – 3 m, 31. i. 2018; 1 ♀, Savanne, Bel Ombre, 20 ° 30 ′ 00 ″ S, 57 ° 23 ′ 34 ″ E, 1 m, 11. xii. 2016, sweeping coastal rocks and sandy beach; 5 ♂, 6 ♀, Savanne, Bel Ombre, 20 ° 29 ′ 32 ″ S, 57 ° 22 ′ 42 ″ E, 1 – 3 m, 26. i. 2018; 33 ♂, 19 ♀, Savanne, Rivière des Galets, 20 ° 30 ′ 04 ″ S, 57 ° 26 ′ 52 ″ E, 1 – 3 m, 26. i. 2018 (1 ♀ deposited LMC). Rodrigues: 9 ♂, 1 ♀, Anse aux Anglais, 19 ° 40 ′ 15 ″ S, 63 ° 26 ′ 19 ″ E, 1 – 3 m, 10. ii. 2018; 1 ♂, 2 ♀, Anse Mourouk, 19 ° 44 ′ 23 ″ S, 63 ° 27 ′ 53 ″ E, 1 – 3 m, 10. ii. 2018; 5 ♂, 7 ♀, Petite Gravier, 19 ° 43 ′ 40 ″ S, 63 ° 29 ′ 03 ″ E, 1 – 3 m, 10. ii. 2018 (1 ♂ deposited LMC); 1 ♂, Plaine Corail, 19 ° 46 ′ 05 ″ S, 63 ° 22 ′ 36 ″ E, 1 – 3 m, 9. ii. 2018; 4 ♂, 2 ♀, Rivière Banane, 19 ° 40 ′ 37 ″ S, 63 ° 28 ′ 30 ″ E, 1 – 3 m, 10. ii. 2018 (all deposited BMSA, unless otherwise stated). Comments: The small genus Pseudorhicnoessa Malloch, 1914, includes three described species, namely: P. rattii, exclusively inhabiting the seashores of the Indian Ocean, and the two very closely related P. longicerca Munari, 2014 and P. spinipes Malloch, 1914, which are distributed in the western Pacific Ocean. Pseudorhicnoessa spinipes is widespread throughout the entire region, whereas P. longicerca is only known from Papua New Guinea. These two western Pacific species can only be differentiated morphologically based on differences in the male terminalia, while P. rattii exhibits a strikingly different shape of both the anterior and posterior surstyli (Figs 14, 15). Aside from these obvious terminalia differences, P. rattii and the other two western Pacific species do not differ significantly in either their external characters or their general habitus; the habitus being extraordinarily similar in all three species. The slight male terminalia divergence in both P. longicerca and P. spinipes indicates a very recent process of sympatric speciation, while the vicariant P. rattii from the Indian Ocean (west of the Sunda Islands) probably diversified in relatively more ancient times. Pseudorhicnoessa rattii was previously recorded from Mauritius by Munari (1990) and is reported here for the first time from Rodrigues.	en	Munari, Lorenzo, Kirk-Spriggs, Ashley H., Mcgregor, Gillian K. (2020): The beach flies of the Mascarene Islands (Diptera: Canacidae: Tethininae). Zootaxa 4853 (2): 183-198, DOI: 10.11646/zootaxa.4853.2.2
