Checklist of the dragonflies and damselflies from Guyana ( Insecta : Odonata ) , with new records from the country

The first checklist of the odonates from Guyana is presented, including 46 new species records. Literature sources are provided for all species and for the new records full locality data, color scans or field photographs, taxonomic and biological notes, and maps for those species whose distribution range is increased considerably.


IntroductIon
Guyana is probably the least well known country in northern South America regarding the odonate fauna.Erichson was the first author to address the odonates from Guyana specifically, describing several species based on material from that country (Erichson in Schomburgk 1848).E.B. Williamson, together with his father L.A. Williamson and his friend B.J. Rainey, collected odonates in Rockstone and Wismar in the Upper Demerara-Berbice Region and Tumatumari in Potaro-Siparuni Region during less than a month in 1912, and in the course of several years after that collecting trip described numerous new species from Guyana based on their findings (Williamson 1915(Williamson , 1916(Williamson , 1917(Williamson , 1919(Williamson , 1920(Williamson , 1923a(Williamson , 1923b;;Williamson & Williamson 1924, 1930).More than 40 records and descriptions of libellulids by Ris (1919) were also based on Williamson's specimens from Guyana.Calvert (1948) published a paper on the odonates from Kartabo in the Cuyuni-Mazaruni Region.Subsequently there have been some additional records from the country in descriptions and revisions in the taxonomic literature, but otherwise Guyana was terra incognita for odonates until recently.
Three surveys in the central western and eastern portions of the country that took place in 2014 (Biodiversity Assessment Team surveys of the Kaieteur Plateau-upper Potaro area, Konawaruk River system, and upper Berbice watershed) increased the number of known odonate species from 192 to 225.Examination of specimens in collections added another five new records, and a fourth expedition in 2015 (CEIBA, Karanambu, and Iwokrama) registered an additional eight, resulting in a total of 238 species recorded from Guyana to date.

MAterIAls And Methods
The following checklist was compiled based on the first reliable literature record of a particular species from the country, indicated in square brackets ([ ]) next to each species, from examined specimens in collections not yet recorded in the published literature, and from material collected in surveys of the Kaieteur Plateau-upper Potaro area, Konawaruk River system, and upper Berbice watershed in 2014, and CEIBA, Karanambu, and Iwokrama in 2015.The 46 new country records are highlighted in bold, and are accompanied by full locality data, distributional, taxonomic and/or biological notes, and color scans or field pictures.Distribution maps are provided for those species whose range in the Guiana shield or South America has increased considerably as a consequence of these new records .Acronyms for collections where studied specimens are deposited are as follows: The classification followed is that outlined in Dijkstra et al. (2013).Color scans were performed with an Epson Perfection 4870 scanner.Maps were created electronically with ArcView 9.1.

Dicterias cothurnata]
Megapodagrionidae Dimeragrion percubitale Calvert, 1913[Calvert 1913] Heteragrion ictericum Williamson, 1919[Williamson 1919] Heteragrion pemon De Marmels, 1987. 15 (De Marmels 1987;Fig. 51).Adults were found perching on tips of low twigs along forest trails.Sjöstedt, 1918[Williamson 1919 as H. melanurum] Note.De Marmels (1987) examined the holotype of Heteragrion silvarum Sjöstedt, 1918, and commented on its similarity with H. melanurum described from Guyana, from which the holotype differs only by the absence of a dark dash between the eye and the base of the antenna.Examined specimens of H. silvarum from Brazil show variability in the extension of the dark areas on the head and spots in that position, indicating that these two names most likely represent synonyms, and therefore, following Lencioni (2013) the older name H. silvarum is used here.

Heteragrion silvarum
[CSBD; CSCA; RWG].Only teneral adults of this species were found.Since the survey took place at the end of the dry season spanning from February to April, this is an indication that it is most likely a rainy season species.Described from French Guiana and also known from Venezuela, this record in an intervening area was not unexpected.
Euthore sp.[Bick & Bick 1992 as E. hyalina] Note.Bick & Bick (1992) reported E. hyalina (Selys, 1853) from Venezuela, Colombia, Guyana and Peru.De Marmels (2010) considered the record from Venezuela as highly questionable and stated that E. hyalina is likely restricted to Colombia.The male from Demerara on which the Guyanese record by Bick & Bick (1992) was based, deposited at FSCA, was kindly photographed by Bill Mauffray at our request.According to the photograph, wings are not entirely hyaline, as it would be expected for E. hyalina, having distal third slightly infumated preceded by an opaque area.Species concepts in this genus are unclear (Garrison et al. 2010) and available keys (Bick & Bick 1992) are based solely on wing color without taking into account intraspecific and age related variability; a revision of the group is necessary to clarify species definitions and distributions.

Tholymis citrina
Zenithoptera fasciata (Linnaeus, 1758) [Erichson in Schomburgk 1848, as Diastatops fasciata] dIscussIon Compared to the total species number of odonates registered from neighboring countries, more than 500 from Venezuela (De Marmels 1990b, 2015) and almost 300 from Suriname (Belle 2002;von Ellenrieder 2011), the 238 species recorded for Guyana still constitute a strikingly low number considering the diversity of habitats and topography that Guyana hosts, and further sampling will undoubtedly increase it further.

AcKnowledgMents
Our gratitude to Rosser W. Garrison for his critical reading of the manuscript; to Jürg De Marmels and an anonymous reviewer for their comments and corrections on the manuscript; to Benjamin Price, curator at the BMNH, for looking for and photographing the two specimens of Sympetrum from Mt. Roraima in Guyana; to Bill Mauffray, curator of the FSCA, for photographing the male of Euthore recorded from Guyana; and to Ângelo P. Pinto for sending photographs of the type specimens of Ypirangathemis calverti and sharing unpublished locality data.The senior author thanks WWF Guyana and Global Wildlife Conservancy for inviting her to participate in the 2014 BAT surveys, and Wenceslaus Washington, Nadine Johnson, Regius Edwards, Louis Skybar, Lewis Skybar, Rupert Williams, Paul Benjamin, Richie Mohabie, Joemaine Archer, and Rosser W. Garrison for their assistance in the field and specimen collection.unior authors thank Iwokrama Research Center for permission to visit the station.Funding for EIS was obtained from STINT (Sweden) and the Swedish Research Council (VR).

Figure 51 .
Figure 51.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.

Figure 52 .
Figure 52.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.

Figure 53 .
Figure 53.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.

Figure 54 .
Figure 54.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.

Figure 55 .
Figure 55.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.

Figure 57 .
Figure 57.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.

Figure 57 .
Figure 57.Distribution of species recorded for the first time from Guyana showing a considerable range extension.Shaded area: Guiana Shield.