Checklist and distribution maps of the blow flies of Venezuela (Diptera, Calliphoridae, Mesembrinellidae)

Abstract A checklist of the 39 species of blow flies (Calliphoridae and Mesembrinellidae) so far known to occur in Venezuela is provided, based on a thorough literature review and the examination of ca. 500 specimens deposited in the main entomological collections of the country. Data from the literature and museum collections were used to generate distribution maps for 37 species. Three species are recorded from Venezuela for the first time: Chrysomya putoria (Wiedemann, 1830), Mesembrinella spicata Aldrich, 1925 and Mesembrinella umbrosa Aldrich, 1922.


Introduction
Blow flies (also known as bluebottles, greenbottles, cluster flies and generically referred to as carrion flies) is the vernacular name traditionally used for the para/polyphyletic family Calliphoridae sensu lato. Historically, the taxonomic composition and phylogenetic relationships within this group of flies, belonging to the superfamily Oestroidea, Many authors have contributed to reviewing the taxonomy of Neotropical Calliphoridae sensu lato (i.e., Shannon 1926, Aubertin 1933, Hall 1948, Mello 1961, 1962, 1967, James 1970, Guimarães 1977, Dear 1979, 1985, Peris 1990, 1992, Mariluis et al. 1994a, 1994b, Mello 1996, Mello 2003, Peris and González-Mora 2005. In more recent taxonomic studies from the region, Vargas and Wood (2012) provided a comprehensive review and key to Central American genera; Whitworth (2010) studied the species present in the West Indies, providing keys and reviewing some species, as well as describing a new one; the same author carried out a complete revision of the six species of Calliphora Robineau-Desvoidy, 1830 from the Neotropical Region (Whitworth 2012) and a revision of 23 species of the genus Lucilia Robineau-Desvoidy, 1830 found in the Neotropics, where he provided an identification key and described six new species (Whitworth 2014). The recent revisions of some genera of Mesembrinellidae, including descriptions of new species (Wolff et al. 2012, Wolff 2013, 2014 and the first phylogenetic study of this family , have been significant. There are also a list of valid blow fly names from the Americas south of Mexico provided by Kosmann et al. (2013) and a catalogue of Calliphoridae and Mesembrinellidae of Colombia (Wolff and Kosmann 2016).
In this paper, for the first time, a checklist is presented of valid species names of Calliphoridae and Mesembrinellidae so far known to occur in Venezuela, as well as distribution maps of each species in the country.

Materials and methods
The checklist is based on the examination of adult blow flies deposited in Venezuela's main entomological collections, combined with our own data and a detailed bibliographic review. We examined specimens housed in the following museums and institutions: Some of the specimens deposited in CEUA and IVIC were collected by the authors using Wind Oriented Traps (WOT) baited with fish and pig liver (see Vogt et al. 1985). The classification used in the checklist follows Rognes (1986Rognes ( , 1991Rognes ( , 1997 and Marinho et al. (2016). The material examined was identified on the basis of specific keys for each subfamily of Calliphoridae, i.e. Mariluis and Peris (1984) and Whitworth (2012) for Calliphorinae; Mariluis and Peris (1984), Mariluis et al. (1994b), Rognes (1994) and Whitworth (2010Whitworth ( , 2014 for Luciliinae; Dear (1985), González-Mora et al. (1998), Mariluis et al. (1994a), Rognes and Paterson (2005), Whitworth (2010) and Grella et al. (2015) for Chrysomyinae, and Dear (1979) for Toxotarsinae. In the case of Mesembrinellidae the keys of Guimarães (1977), Bonatto and Marinoni (2005) and Wolff et al. (2014) were used. The dissection and study of male terminalia were carried out following Whitworth (2006Whitworth ( , 2010. The identity of all specimens was confirmed by Dr Terry Whitworth from Washington State University (USA).
Localities of occurrence of both the examined material and records taken from the literature were georeferenced using Google Earth (v7.1.5.1557). Distribution maps were created with ArcView GIS 10.2 (Environmental Systems Research Institute, Inc., USA). Each point plotted on the maps represents a locality of occurrence. Distributions of species do not follow any alphabetic or taxonomic criterion but are instead represented in such a way as to avoid, as far as possible, the overlapping of dots. Table 1 lists a total of 39 species of blow flies for Venezuela, of which 25 are Calliphoridae and 14 Mesembrinellidae. We examined a total of 498 specimens, the subfamily Chrysomyinae being the most abundant (302), followed by the Luciliinae (166). From the material examined we identified 26 species, including one Calliphoridae and two Mesembrinellidae newly recorded for the country: Chrysomya putoria (Wiedemann, 1830), Mesembrinella spicata Aldrich, 1925 andMesembrinella umbrosa Aldrich, 1922. Doubtful records found in the literature were excluded from the list when there was no indication of how the species were identified or when the accuracy of the identifications was uncertain. Distribution maps showing the records obtained from the material examined and the literature are provided for 37 species (Figs 1-14). Eumesembrinella randa (Walker, 1849) and Lucilia sericata (Meigen, 1826) were cited for Venezuela by Peris and Mariluis (1984), Mariluis et al. (1994b), Kosmann et al. (2013) and Wolff and Kosmann (2016), but no locality information was provided.  Kosmann et al. (2013), Wolff and Kosmann (2016) MIZA

Discussion
This study is the first to determine the diversity of Calliphoridae and Mesembrinellidae in Venezuela. The checklist contains a total of 39 species of Calliphoridae, with 25 species distributed in ten genera, and Mesembrinellidae, with 14 species distributed in six genera. Twenty-six species were identified from examined material, while 13 species are listed based exclusively on records found in the literature. Compared to neighbouring countries that have been relatively well-studied, the known Venezuelan blow fly fauna is equivalent to that of Brazil (39 species: 24 Calliphoridae in eight genera and 15 Mesembrinellidae in seven genera) (Kosmann et al. 2013), but less diverse than that of Colombia (52 species: 31 Calliphoridae in 12 genera and 21 Mesembrinellidae in seven genera) (Wolff and Kosmann 2016). Three species are newly recorded for the country: Chrysomya putoria, Mesembrinella spicata and M. umbrosa. These records were not unexpected, as these species have been found in other South American countries: C. putoria in Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay and Peru (Baumgartner 1988, Wolff andKosmann 2016), M. spicata in Costa Rica and Colombia Marinoni 2005, Kosmann et al 2013), and M. umbrosa in Bolivia, Colombia and Ecuador (Guimarães 1977, Wolff and Kosmann 2016.
The absence from the examined material of species previously recorded in Venezuela or in neighbouring countries reflects the lack of study of these flies in this region. As an example, Chloroprocta idioidea, the only species of the genus Chloroprocta Wulp, 1896 (Calliphoridae), was recorded in Venezuela by Hall (1948), Cova (1964), Dear (1985) and Kosmann et al. (2013) and was the most abundant (66.3% of the total sampled specimens) species collected in a recent survey of necrophagous flies in the North Brazilian Amazon (Amat et al. 2016). However, it was not found in any Venezuelan museum and only two specimens from Venezuela were examined, from BMNH. In his recent revision, Whitworth (2014) reported Lucilia albofusca and L. vulgata for Venezuela, but we did not find these two species in our field sampling or in entomological collections. Some authors reported L. cluvia and L. sericata in Venezuela (Mariluis et al. 1994b, Kosmann et al. 2013), but neither was found during this study. It is unlikely that L. cluvia occurs in the country, since Whitworth (2014) argued that reports of this species in South America are incorrect. On the other hand, Lucilia sericata has been reported as abundant in neighbouring countries such as Colombia and Brazil (Carvalho and Ribeiro 2000, Pape et al. 2004, Amat et al. 2008, so its absence during this study was surprising. This was also the case of other species previously cited for Venezuela, such as Compsomyiops fulvicrura, Hemilucilia benoisti, Paralucilia paraensis, Eumesembrinella quadrilineata, Eumesembrinella randa, Giovanella bolivar, Huascaromusca vogelsangi, Mesembrinella bellardiana and Mesembrinella xanthorrhina (Aldrich 1922, Shannon 1926, Hall 1948, Cova 1964, Guimarães 1977, Dear 1985, Peris and Mariluis 1989, Mariluis et al. 1994a, Bonatto and Marinoni 2005, Kosmann et al. 2013. The absence of these species in our samples could be related to non-exhaustive field sampling and/or to the heterogeneous composition of the examined entomological collections. During this study, some specimens of Lucilia and Mesembrinellidae could not be identified as any known species. These specimens may represent undescribed species and for this reason were not included in the checklist. Some species of these groups are morphologically highly variable and further studies are required to determine whether they are separate species or examples of intraspecific variation (Whitworth, pers. comm.). If possible, we strongly recommend rearing specimens from live females collected in the field in order to obtain enough specimens to study the intraspecific variability of both these groups of blow flies.
The distribution maps obtained from the data available (Figs 1-14) show that the current distribution of Venezuelan blow flies is clearly determined by an unequal sampling effort around the country. Most records are from the predominantly mountainous north, where protected areas such as natural parks were the main collection sites. This sampling effort bias makes it difficult to draw any conclusions on the habitat preferences of these species, hence the necessity of further studies. In any case, the presence of some species in areas with less human disturbance adds value to these flies as indicators of the state of habitat conservation. This, in addition to the interest in these species in medicolegal and veterinary fields, will hopefully provide incentive to perform further studies on Venezuelan blow flies.
Zoological Institute Francisco Fernández Yépez (UCV) and Prof. Evelin Arcaya at the Entomological Museum "Dr. José Manuel Osorio" (UCLA) for lending us the specimens used in this work. We are grateful to Dr Angel Viloria at the Venezuelan Institute for Scientific Research and Prof. Carlos Blanco at the Guáquira Biological Station for providing support during fieldwork in Venezuela. We acknowledge the assistance of Dr Martin J.R. Hall and Mr Nigel Wyatt during our stay at the Natural History Museum (London, UK). We are especially grateful to Mr Terry Whitworth from Washington State University for the identification of specimens and the valuable clarifications on the taxonomy of blow flies from the Neotropics, and also for his careful reading of the manuscript. This research received support from the SYN-THESYS Project (http://www.synthesys.info/), which is financed by the European Community Research Infrastructure Action under the FP6 Program "Structuring the European Research Area". This work was partially supported by the Valencia Autonomous Government (Generalitat Valenciana) (GV/2011/039) and the University of Alicante (GRE09-27).