This paper documents the horse fly fauna collected in lowland rainforest in the southwesternmost part of French Guiana (Mitaraka). During this “Our Planet Revisited” survey nine tabanid species were recorded from French Guiana for the first time: Chrysops ecuadorensis Lutz, C. incisus Macquart, Catachlorops amazonicus Henriques & Gorayeb, Chlorotabanus flagellatus Krolow & Henriques, Cryptoylus cauri Stone, Phaeotabanus phaeopterus Fairchild, Philipotabanus stigmaticalis (Kröber), Stypommisa captiroptera (Kröber) and Tabanus amapaensis Fairchild. An updated check list of Tabanidae of French Guiana is presented, including 79 species and one unidentified Chrysops.

MITARAKA

A new species of Thecomyia Perty, 1833, T. diederiki Mortelmans n. sp., is described from French Guiana, with diagnostic characters being the absence of anteromedial setae on the midfemur; an illdefined, tripartite, greyish mesonotal stripe; absence of upper fronto-orbital bristles; completely yellow mid- and hind femora; typical distiphallus bearing two long, curved acrophalli; absence of male anterior gonostyli; and large, triangular posterior gonostyli. All specimens were collected during the Mitaraka (French Guiana) 2015 survey that investigated an array of habitat types; the new species was encountered only in swamp forests. This discovery raises the number of species in this exclusively Neotropical genus to 13. An update of the relevant couplets in the key to Thecomyia in Marinoni et al. (2003) is presented to include the new species. New records of other species of Thecomyia from Costa Rica, French Guiana, and Brazil are given, with first records of Thecomyia lateralis (Walker, 1858) from Costa Rica, and first records of T. diederiki Mortelmans n. sp. and T. longicornis Perty, 1833 from French Guiana.

MITARAKA

The genus Enlinia Aldrich, 1933 is recorded from French Guiana for the first time and six new species are described: E. loboptera n. sp., E. bova n. sp., E. colossicornis n. sp., E. mitarakensis n. sp., E. touroulti n. sp., and E. dalensi n. sp. A seventh unnamed species belonging to the E. armata Robinson, 1969 species group, and represented by a single female specimen, is also reported. These species were collected as part of the 2015 “Our Planet Revisited” survey in the Mitaraka Mountain area in far southwestern French Guiana. A key to the seven species known from French Guiana is provided.

MITARAKA

This article introduces the biodiversity survey “Our Planet Reviewed” in the south of French Guiana organized in February-March and August 2015. It has enabled more than 50 scientists to inventory the following groups: Actinopterygii, Amphibia, Annelida, Arachnida, Insecta, Mollusca and Squamata, with a particular effort on diverse and little-known orders, such as Coleoptera, Diptera, Hemiptera and Hymenoptera. The forested area under investigation presents a mosaic of hills and inselbergs, with a wide variety of ecosystems. The main objectives were to discover new species for science, report first records for French Guiana, and establish a baseline inventory for biogeographic studies. The organisation of the field trip and post-field phase are supported by coordinators of major taxonomic groups. Authorisations and associated commitments, including Access and Benefit Sharing (ABS) are specified. The sampling effort, in terms of number and diversity of methods, is certainly the largest ever made in French Guiana over a short period of time. Thirteen different trap types were used including four types of interception traps and nine types of attraction-based traps. Active research methods (13 techniques) and extraction from the substrate (five techniques, including Winkler sieves, emergence from dead wood, etc.) completed the sampling array. The sample processing procedure describes the difference between active collecting and the longer and more complex process of processing massive samples of traps such as window pane flight intercept traps, Malaise traps, colored pan traps and automatic light traps. After a sorting phase that lasted less than a year for most groups, a network of 165 taxonomic experts was mobilized by the coordinators to study the sorted specimens. The data are stored and managed in an observations database and in the database of the collections of the Muséum national d’Histoire naturelle (Paris). Data are widely disseminated, notably in France via the Inventaire national du Patrimoine naturel (INPN) and internationally by the Global Biodiversity Information Facility (GBIF). This introductory article will be supplemented by a second paper, which will analyse research results three years after the survey and assess the effectiveness of the expedition in advancing taxonomic knowledge.

MITARAKA