Annotated checklist of the Dermaptera (Insecta) of French Guiana

ABSTRACT We establish the first checklist of the earwig species from French Guiana, updating previous works. This list comprises 49 species distributed in five families: Pygidicranidae Verhoeff, 1902, Forficulidae Stephens, 1829, Labiduridae Verhoeff, 1902, Spongiphoridae Verhoeff, 1902, Anisolabididae Verhoeff, 1902. Twentyfour species are cited for the first time from French Guiana and five species are only mentioned from bibliographical records. Three misidentified records are discarded. Species diversity in French Guiana is similar to neighboring countries and a few additional species will probably be found. Some poorly recorded species have been found, such as Cosmogerax araguensis (Brindle 1974), Cosmogerax doesburgi Brindle 1982, Sarcinatrix quadrimaculata Brindle 1971, Doru unicolor Brindle 1971, Purex surinamensis Brindle 1971, Spongiphora buprestoides (Kirby 1891). Purex formosus Hebard 1920, described from French Guiana, has been rediscovered in the Mitaraka mountains and its female collected for the first time. We provide comments on some species and on a few undetermined specimens and indicate some taxonomic challenges unresolved in French Guiana.


INTroDuCTIoN
French Guiana is a French overseas territory located in the Guiana Shield, that occupies 83 350 km 2 . It is mostly composed of primary tropical forests, but some savannas are also present around the coast. This territory has been well studied concerning vertebrates, but the invertebrates remain poorly known. Its insect diversity has been recently estimated at 100 000 species (Brûlé & Touroult 2014).
Dermaptera (earwigs) is a small insect order of about 2000 species with a greater diversity in tropical regions, especially in South-East Asia and in the Neotropics (Popham 2000). In Central and South America, species knowledge remains poor although several taxonomical and geographical accounts have been published between 1960and 1980mostly (Brindle 1968a, b, 1971b, c, d, 1974, 1982reichardt 1968a, b, 1970, 1971). Many of the newly described species are known by a few specimens only. More recently, a few additional species have been described from South America (Anisyutkin 2014; Kamimura & Ferreira 2017).
As a consequence, the species distributions are largely unknown although biodiversity estimates have recently been provided for nearly all countries (Haas 2018).
In French Guiana, the only available works are that of Brindle (1968b) and Hebard (1920) who cited 14 and 12 species, respectively. The monographs of Steinmann (1986, 1989a, b, 1993) mentioned 25 species. More recently, Thouvenot (2011) mentioned 15 species but did not establish any detailed checklist.
We here establish a checklist of the Dermaptera of French Guiana, based on recently collected material, with comments on several interesting species.

MATErIAL AND METHoDS
We have had recently the opportunity to study a very large amount of specimens, collected mostly between 2009 and 2015 in various parts of French Guiana. Most of the specimens have been collected during field works of the Société entomologique des Antilles et de la Guyane (SEAG) between 2009 and 2015.
on the other hand the international biotic survey "our Planet reviewed" ("La Planète revisitée" French Guiana 2014Guiana -2015 aimed at rehabilitating taxonomic work on inverterbrates, mostly by enabling the discovery of species new to science or new to French Guiana, but also by collecting specimens on poorly known species of different insect orders (Touroult et al. 2018). This survey took place in March 2015 and enabled to collect several interesting and scarcely collected specimens; it gave us a very good opportunity to publish the first checklist of Dermaptera from French Guiana. In addition, several specimens from other collectors in French Guiana (see Acknowledgements for a complete list) have also been transmitted. Several collecting methods have been used: light traps, interception traps, malaise traps and active searching.
Specimens from the following museums have also been examined, either directly or by the mean of photographs of type specimens: -Muséum national d'Histoire naturelle, Paris (MNHN): all specimens collected in French Guiana and stored at the museum, including holotypes of Purex formosus (Hebard, 1920) and Paralabella chopardi (Hebard, 1920). -Naturalis Museum, Leiden, The Netherlands (holotype picture of Purex surinamensis) -Maracay Museum, Venezuela (holotypes pictures of Gerax fuscum and Gerax lucidum).
Pictures of type specimens of other species have also been examined when available in Fabian Haas' website (ww.earwigsonline.de, no longer available). Location of type specimens is indicated for each species, when known.
More than 1770 specimens have been studied so far among which 555 specimens are mentioned in the present paper. The specimens are cited in the following way: town, precise location (with GPS coordinates when known), collecting date, collector, number of specimens and storage collections.
Pictures were taken with a Canon EoS1500D using Capture one pro software. Digital images were then obtained by using CombineZP software.
The taxonomy and nomenclature follow the Dermaptera species file (HoPKins et al. 2013), with some minor changes (Engel & Haas 2007;Srivastava 1999). The genera and species are listed under their families. The municipalities where the species have been found are indicated. The taxonomical informations are presented in the following way : city, exact place, date, leg. or coll., specimens number, collection or institution where the specimens is stored. remArks Already cited from French Guiana (Hebard 1920;Brindle 1968b). Several subspecies exist. The subspecies to which the collected material belongs has not been identified yet. It is a common species in French Guiana. Borelli, 1904  remArk Identification still temptative as no picture of type specimen could be studied, but the specimen matches well with the descriptions. remArk Also cited from French Guiana by Brindle (1968b).

Pyragra paraguayensis
Metalabis saramacensis (Zacher, 1911) remArk Cited from French Guiana by Hebard (1920), Thouvenot (2011) andBrindle (1968b). Easily recognized by its orange wings, pronotum and legs and by the two orange spots on the forewings. Seems rather common in French Guiana. Carcinophora scudderi (de Bormans, 1900)  remArk This species has been described from Surinam, and is poorly known. Two specimens apparently belonging to this species have been identified from Mount Itoupé. The species has already been cited from French Guiana (Haas 2009) on the basis of one specimen supposedly present in the MNHN collection in Paris but not seen. ZOOSYSTEMA • 2020 • 42 (4) Metalabis saramacensis (Zacher, 1911) Eulabis saramacensis Zacher, 1911:  remArks This species is difficult to identify although the presence of an arolium and the large eyes were diagnostic for the genus Gerax. We have been able to compare our specimens with photographs of type specimens of Gerax fuscum Brindle, 1974 andGerax lucidum Brindle, 1974, also stored at MIZA. Both species were described on a single male specimen. According to our specimens, the differences stated in Brindle's descriptions (1974) are scarce: concerning the colour of pronotum and wings, our specimens vary from pure yellow (Gerax lucidum) to yellow suffused with brown (Gerax fuscum); pending further investigations we refer all our specimens as Gerax fuscum. It is likely that the two species are to be synonymized in the future.  remArk Already cited from French Guiana by Brindle (1971c). Apparently a rare species that might be undercollected due to its minute size.

remArk
The identity of the specimens has been confirmed by comparison with photographs of the type specimen, deposited at Leiden. It has apparently rarely been collected since its description.  distribution. -Guadeloupe, Martinique, Brazil, Venezuela, French Guiana, Suriname and Dominica (Steinmann 1989b;Brindle 1971c, d, e).

remArk
The specimen from the MNHN closely matches the illustrations of Burr (1912) and Brindle (1971d, e) specimens from West Indies (and is also identical to our specimens from Martinique, Trinité, le Galion, 21.V.2014, PD. Lucas leg., 1 female, 1 male, coll. CGIr) but differs from the original description by Dohrn (1864). As pointed out by Hebard (1920), Labia ghilianii was described based on several syntypes that may belong to different species. The type locality is from Brazil, by designation from Hebard (1920).
Spongovostox schwarzi (Caudell, 1907) (Haas 2018). Thirty-seven species were recorded from Surinam and 14 from French Guiana by Brindle (1968b). A few additional ones have since then been described (Brindle 1971b(Brindle , 1982 and it is likely that the number of species is probably similar in these two countries, but Surinam has until now been less studied than French Guiana. In the Guiana Shield, Venezuela has a greater diversity with 85 species recorded, which is probably due to its larger size and to its altitudinal range (up to 4978 m) which enable more diversity. Still, the number of species in French Guiana is probably underestimated, as several undetermined specimens which do not belong to any of the species mentioned in our checklist are still under studies. The number of localities studied up to know is scarce, and many species have only been found in one or two places. Thus, it is likely that additional species will be found when new places are studied. Furthermore, the collecting methods probably induced a bias towards winged species. Many wingless species occur around the world and in the Neotropics, and some of them might be found in French Guiana; as most of the collecting methods used aerial traps or nets, it is likely that wingless species are less collected than winged ones. In addition, it was also shown in Africa that some species occur more frequently in canopy than at the ground level (Haas & Klass 2003). Many earwigs species are found in epiphytic plants, in particular bromeliads (Picado 1913;Brindle 1974). Additional research on the entomological fauna of the canopy will probably lead to new discoveries.
biogeogrAPhicAl dAtA It is tentative to establish any tendancies, because some places have been more prospected than others, so bias might occur. However, while some species such as Spongiphora croceipennis, Kleter aterrima, Carcinophora percheroni, Vostox brunneipennis, Circolabia arcuata are widely distributed in French Guiana (and have been collected many times), some others have only been recorded in a few places. For instance, Neoopisthocosmia geijskesi has only been collected on the inselbergs and high summits of French Guiana (and was described from an inselberg in Suriname). Mount Itoupé in particular, being one of French Guiana highest mountain (830 m), gives shelter to rare and interesting species (Doru unicolor, Sarcinatrix quadrimaculata, Purex surinamensis). Mitaraka mounts also display a high diversity, with 12 species recorded (24.5 % of French Guiana diversity) and at least four additional species that could not be identified up to know, and are thus not mentioned in this paper. Some of the species recorded there are widely distributed (Kleter aterrima, Spongiphora croceipennis, Carcinophora scudderi, Carcinophora percheroni), but a few other (Cosmogerax doesburgi, Eugerax poecilum) have only been recorded from this place. In addition, Purex formosus was rediscovered in these mounts, a century after its first collecting near Kourou. Further studies will be necessary to establish if any biogeographical trends in earwigs distribution occurs in French Guiana. Most problems deal with Spongiphoridae. Thus, some other Geracinae have been collected in French Guiana. However, they could not be assigned to a species with enough confidence, due to rarity of specimens. The Spongiphorinae are also taxonomically very diverse and very difficult to identify, especially for species which are only known by a few specimens. Many unidentified species of Marava, Spongovostox and Purex are present in our collection. In addition, as pointed out above, Spongovostox ghilianii probably refers to more than one species, but it is unclear whether a name is available for the specimens from French Guiana. Despite these taxonomical issues, this checklist of the earwigs of French Guiana enabled to provide some new information which update Thouvenot (2011), Brindle (1968b and Hebard (1920). It will hopefully be completed, in the next years, by additional data on the unidentified specimens and their distribution in French Guiana. We also hope that it will be of help for other entomologists collecting in the Neotropics to identify their specimens and that it will bring attention to this somehow neglected order.