Biodiversity Data Journal : Data Paper (Biosciences)
Data Paper (Biosciences)
Terrestrial arthropods of Steel Creek, Buffalo National River, Arkansas. IV. Asilidae and other Diptera
expand article infoMichael Joseph Skvarla‡,§, Jeffrey K. Barnes, Danielle M. Fisher, Ashley P. G. Dowling
‡ University of Arkansas, Fayetteville, Arkansas, United States of America
§ University of Maryland, College Park, Maryland, United States of America
Open Access



This is the fourth in a series of papers detailing the terrestrial arthropods collected during an intensive survey of a site near Steel Creek campground along the Buffalo National River in Arkansas. The survey was conducted over a period of eight and a half months in 2013 using twelve trap types, including Malaise and canopy traps, Lindgren multifunnel traps, and pan traps.

New information

We provide collection records for 38 species of Asilidae and other Diptera, 7 of which are new state records for Arkansas: (Asilidae) Lasiopogon opaculus Loew, 1874; (Lygistorrhinidae) Lygistorrhina sancthecatharinae Thompson, 1975; (Stratiomyidae) Cephalochrysa nigricornis (Loew, 1866), Gowdeyana punctifera (Malloch, 1915), Sargus decorus Say, 1824; (Ulidiidae) Callopistromyia annulipes Macquart, 1855; and (Xylophagidae) Rachicerus obscuripennis Loew, 1863.


The Interior Highlands is mountainous region in the central United States. It has remained exposed for the last 270 million years and has historically acted as a refugium during times of inhospitable climate (Skvarla et al. 2015). Due to its history and geography, the region is a biodiversity hotspot that supports more than 200 endemic species (Allen 1990, Robison and Allen 1995, The Nature Conservancy, Ozarks Ecogegional Assessment Team 2003, Pringle and Witsel 2005, Zollner et al. 2005, Robison et al. 2008, Skvarla et al. 2015). However, compared to similar biodiversity hotspots, such as the Southern Appalachians, the Interior Highlands in general has been poorly surveyed. This paper, which focuses on Asilidae and certain other Diptera, is the fourth in a series that detail a survey at Steel Creek in Northwest Arkansas (see Skvarla et al. 2015 for select Coleoptera, Skvarla et al. 2016b for "Symphyta", and Skvarla et al. 2016a for Heteroptera).

Because this paper covers species from a variety of fly families, we provide the following summaries of each family and lower taxon treated.

Anisopodidae comprises 154 species world wide, including nine that are present in North America, five of which belong to Sylvicola (Pape et al. 2011, Pratt and Pratt 1980). Larval Sylvicola generally develop in decaying organic matter and may become pestiferous in sewage treatment plants (Pratt and Pratt 1980).

Asilidae, the members of which are commonly known as robber flies, are a diverse family of exclusively predatory flies. More than 7,500 species in approximately 550 genera are known worldwide, of which approximately 1,040 species in 100 genera occur in North America north of Mexico (Pape et al. 2011, Geller-Grimm 2016).

Stratiomyidae include approximately 2700 species arranged in more than 380 genera worldwide; more than 250 species in 41 genera are present in North America north of Mexico ( Woodley 2001). While some species are relatively large-bodied and commonly encountered, such as the black soldier fly, Hermetia illucens (Linnaeus, 1758), others are smaller in size and easily overlooked. Sargus, Cephalochrysa, and Gowdeyana are examples of such taxa, and are also relatively depauprate in North America, with 6, 4, and 2 species, respectively (Woodley 2001).

Lygistorrhinidae is an uncommonly collected family of Sciaroidea that is easily recognizable by the generally elongate proboscis and reduced wing venation (Thompson 1975). Of the extant taxa, Lygistorrhina (Probolaeus) Williston, 1896, which is sometimes considered a separate genus, contains nine species and is the only (sub)genus to occur in the New World, with the remaining seven genera and Lygistorrhina (Lygistorrhina) restricted to the Old World (though note that Huerta and Ibañez-Bernal 2008 reported an undescribed L. (Lygisstorrhina) from Mexico) (Papavero 1978, Vockeroth 2009, Fungus gnats online 2015). Only one species, L. santaecatharinae Thompson, 1975, is known from North America north of Mexico (Fungus gnats online 2015).

Little is known about lygistorrhinids. Most specimens are collected using passive traps (i.e., Malaise traps) or by sweep netting vegetation and almost nothing is known about their behavior and biology, including the immature stages (Vockeroth 2009).

Ulidiidae, commonly known as picture-wing flies, are distinctive for the striking wing patterning and propensity of some species to wave or flash their wings. The peacock fly, Callopistromyia annulipes, is especially noticeable as it often holds its wings above the thorax.

Rachicerus Walker, 1854, the most speciose genus of Xylophagidae, contains approximately half of the known species worldwide, and is the only genus of Xylophagidae present in tropical forests (Woodley 2011). It is also the easiest genus of Xylophagidae to identify as it is the only one in which the antennae are composed of ten or more flagellomeres and may be pectinate (Webb 1984). Five species of Rachicerus are present in the Nearctic; two are restricted to the coastal forests of the Pacific Northwest and three – R. fulvicollis Walker 1854, R. nitidus Johnson, 1903, and R. obscuripennis Loew, 1863 – are found in the eastern United States and Canada (Webb 1984).

Sampling methods

Sampling description: 

The sampling protocol was covered in detail by Skvarla et al. (2015). The following summary is provided for convenience.

The following traps were maintained within a 4 ha site at Steel Creek, Buffalo National River, Arkansas (see Geographic coverage for a description of the site): five Malaise traps, twenty-five pan traps (five of each color: blue, purple, red, yellow, white) which were randomly arranged under the Malaise traps (one of each color per Malaise trap); fifteen Lindgren multi-funnel traps (five of each color: black, green, purple); four SLAM (Sea, Land, and Air Malaise) traps with top and bottom collectors placed in the canopy; and seventeen pitfall trap sets. Additionally, ten leaf litter samples were collected for Berlese extraction when traps were serviced.

Trap placement began on 8 March 2013 and all traps were set by 13 March 2013, except Lindgren funnels, which were set on 1 April 2013. Traps set earlier than 13 March were reset on that date in order to standardize trap catch between traps. Traps were serviced approximately every two weeks. The last collection of pitfall traps and pan traps occurred on 6 November 2013; Malaise, SLAM, and Lindgren funnel traps were run for an additional month, with the final collection on 4 December 2013. In total, 1311 samples were collected.

RV and marine antifreeze, which contains both propylene glycol and ethanol, was used as the preservative in all traps as it is non-toxic, inexpensive, and preserves specimens reasonably well (Skvarla et al. 2014). Insect escape was impeded by the addition of a squirt of unscented, hypoallergenic dish detergent to the propylene glycol to act as a surfactant. Trap catch was sieved in the field and stored in Whirl-Pak bags in 90% ethanol until sorting.

Quality control: 

Samples were coarse-sorted using a Leica MZ16 stereomicroscope illuminated with a Leica KL1500 LCD light source and a Wild M38 stereomicroscope illuminated with an Applied Scientific Devices Corp. Eco-light 20 fiber optic light source. After sorting, specimens were stored individually or by family in 2 mL microtubes in 70% ethanol until they could be pinned or pointed.

Asilidae were identified by author Barnes, who is an internationally recognized robber fly expert. Specimens of other families were identified using published keys (Table 1).

Table 1.

References used in identification.

Family Genus Reference
General identification McAlpine et al. 1981, McAlpine et al. 1987
Anisopodidae Sylvicola
Drosophilidae Drosophila D. suzukii is a distinctive species, no key necessary
Drosophilidae Zaprionus Z. indianus is a distinctive non-native species, no key necessary
Lygistorrhinidae Lygistorrhina Thompson 1975
Mydidae Mydas M. clavatus is a distincitve species in Arkansas, no key necessary
Oestridae Cephenemyia Bennett and Sabrosky 1972, Taber and Fleenor 2004, Fleenor and Taber 2007
Oestridae Cuterebra Sabrosky 1986
Ptychopteridae Bittacomorpha Distinctive genus represented by a single species in the Eastern United States, no key necessary.
Stratiomyiidae Williston 1885, McFadden 1972, Woodley 2001
Stratiomyiidae Ptecticus McFadden 1971
Xylophagidae Rachicerus Webb 1984

Asilidae were the focal group of this study; all specimens were removed when bulk samples were sorted so specimens reported here reflect the seasonality and relative abundance of the species sampled by the traps at the site. Specimens of other families were not consistentatly removed by everyone who processed samples, so specimens reported here are indicative of a species presence at the site but not other measurements such as seasonality and relative abundance.

All specimens are deposited in the University of Arkansas Arthropod Museum (UAAM).

Geographic coverage


The survey was conducted within a 4 hectare plot established at Steel Creek along the Buffalo National River in Newton County, Arkansas, centered at approximately N 36°02.269', W 93°20.434'. The site is primarily 80–100 year old mature second-growth Eastern mixed deciduous forest dominated by oak (Quercus) and hickory (Carya), though American beech (Fagus grandifolia) and eastern red cedar (Juniperus virginiana) are also abundant. A small (14 m x 30 m), fishless pond and glade (10 m x 30 m) with sparse grasses are present within the boundaries of the site. See Skvarla et al. (2015) for additional details.


36.0367 and 36.0397 Latitude; -93.3917 and -93.3397 Longitude.

Taxonomic coverage

Taxa included:
Rank Scientific Name
order Diptera

Usage rights

Use license: 
Creative Commons CCZero

Data resources

Data package title: 
Steel Creek survey
Number of data sets: 
Data set name: 
Steel Creek Symphyta
Data format: 
Darwin Core Archive
Column label Column description
typeStatus Nomenclatural type applied to the record
catalogNumber Unique within-project and within-lab number applied to the record
recordedBy Who recorded the record information
individualCount The number of specimens contained within the record
lifeStage Life stage of the specimens contained within the record
kingdom Kingdom name
phylum Phylum name
class Class name
order Order name
family Family name
genus Genus name
specificEpithet Specific epithet
scientificNameAuthorship Name of the author of the lowest taxon rank included in the record
scientificName Complete scientific name including author and year
taxonRank Lowest taxonomic rank of the record
country Country in which the record was collected
countryCode Two-letter country code
stateProvince State in which the record was collected
county County in which the record was collected
municipality Closest municipality to where the record was collected
locality Description of the specific locality where the record was collected
verbatimElevation Average elevation of the field site in meters
verbatimCoordinates Approximate center point coordinates of the field site in GPS coordinates
verbatiumLatitude Approximate center point latitude of the field site in GPS coordinates
verbatimLongitude Approximate center point longitude of the field site in GPS coordinate
decimalLatitude Approximate center point latitude of the field site in decimal degrees
decimalLongitude Approximate center point longitude of the field site in decimal degrees
georeferenceProtocol Protocol by which the coordinates were taken
identifiedBy Who identified the record
eventDate Date or date range the record was collected
habitat Description of the habitat
language Two-letter abbreviation of the language in which the data and labels are recorded
institutionCode Name of the institution where the specimens are deposited
basisofRecord The specific nature of the record

Additional information


We collected and identified specimens representing 12 families, 27 genera, and 38 species during this study (Table 2). Seven species, which represent 18% of the total species identified, are recorded for the first time from Arkansas.

Table 2.

Species collected, including total number of specimens. New state records are indicated by an asterisk (*).

Family Genus Species Number of specimens
Anisopodidae Sylvicola Sylvicola fenestralis (Scopoli, 1763) 3
Asilidae Diogmites Diogmites misellus Loew, 1866 6
Asilidae Diogmites Diogmites neoternatus (Bromley, 1951) 1
Asilidae Efferia Efferia aestuans (Linnaeus, 1763) 3
Asilidae Holopogon Holopogon phaeonotus Loew, 1874 3
Asilidae Laphria Laphria divisor (Banks, 1917) 2
Asilidae Laphria Laphria flavicollis Say, 1824 15
Asilidae Laphria Laphria index McAtee, 1919 4
Asilidae Laphria Laphria sicula McAtee, 1919 11
Asilidae Lasiopogon Lasiopogon opaculus Loew, 1874* 2
Asilidae Leptogaster Leptogaster aegra Martin, 1957 1
Asilidae Leptogaster Leptogaster brevicornis Loew, 1872 10
Asilidae Leptogaster Leptogaster flavipes Loew, 1862 1
Asilidae Leptogaster Leptogaster virgata Coquillett, 1904 5
Asilidae Machimus Machimus antimachus (Walker, 1849) 22
Asilidae Machimus Machimus sadyates (Walker, 1849) 6
Asilidae Machimus Machimus virginicus (Banks, 1920) 3
Asilidae Neoitamus Neoitamus flavofemoratus (Hine, 1909) 33
Asilidae Ommatius Ommatius gemma Brimley, 1928 2
Asilidae Ommatius Ommatius ouachitensis Bullington and Lavigne, 1984 3
Asilidae Taracticus Taracticus octopunctatus (Say, 1823) 3
Drosophilidae Drosophila Drosophila suzukii (Matsumura, 1931) 9
Drosophilidae Zaprionus Zaprionus indianus Gupta, 1970 1
Limoniidae Cladura Cladura flavoferruginea Osten Sacken, 1859 26
Lygistorrhinidae Lygistorrhina Lygistorrhina sanctaecatharinae Thompson, 1975* 2
Mydidae Mydas Mydas clavatus (Drury, 1773) 3
Oestridae Cephenemyia 2
Oestridae Cuterebra Cuterebra emasculator Fitch, 1856 1
Oestridae Cuterebra Cuterebra f. fontinella Clark, 1827 4
Ptychopteridae Bittacomorpha Bittacomorpha clavipes (Fabricius, 1781) 1
Stratiomyidae Cephalochrysa Cephalochrysa nigricornis (Loew, 1866)* 1
Stratiomyidae Gowdeyana Gowdeyana punctifera (Malloch, 1915)* 1
Stratiomyidae Ptecticus Ptecticus trivattus (Say, 1829) 680
Stratiomyidae Sargus Sargus decorus Say, 1824* 2
Tipulidae Tanyptera Tanyptera dorsalis (Osten Sacken, 1864) 2
Ulidiidae Callopistromyia Callopistromyia annulipes (Macquart, 1855)* 1
Ulidiidae Idana Idana marginata (Say, 1830) 6
Xylophagidae Rachicerus Rachicerus obscuripennis Loew, 1863* 4

Notes on newly reported species

Lasiopogon opaculus Loew, 1874 (Asilidae) (Fig. 1) is known from Ontario south through Georgia, west to Illinois, Nebraska, and Mississippi (Cannings 2002).

Figure 1.

Lasiopogon, probably opaculus . Collected in copula. All photographs by Gayle and Jeanell Strickland, used with permission.

aFemale, dorsal  
bFemale, lateral  
cMale, dorsal  
dMale, lateral  

Lygistorrhina santaecatharinae (Lygistorrhinidae) has only been reported in the literature on two occasions and is known from localities in West Virginia, Virginia, Georgia, and Tennessee (Fig. 2) (Thompson 1975, Vlach et al. 2010). Shortly after the specimens reported herein were collected, photographs of female L. santaecatharinae feeding on a flower, possibly Rudbeckia, from Buffalo Point recreation area (Marion County, Arkansas), a locality 70 km away from Steel Creek, were posted online (Fig. 3, via Hartley 2015). Not only do the photographs provide an additional locality in Arkansas, but they also provide the first record of nectivory in L. santaecatharinae and apparently the first record of feeding or indeed any behavior in a lygistorrhinid.

Figure 2.  

Lygistorrhina sanctaecatharinae collection localities.

Figure 3.

Lygistorrhina sanctaecatharinae feeding. Photographs by Chris Hartley, used and manipulated with permission.

aTwo L. sanctaecatharinae visiting a flower.  
bCropped detail of figure 2a.  
cThe same two L. sanctaecatharinae as figure 2a at slightly different angles.  
dDetail of figure 2c, clearly showing nectivory.  

Cephalochrysa nigricornis (Loew, 1866) (Stratiomyidae) (Fig. 4) is known from Quebec and Ontario south to Georgia, west to Wisconsin, Minnesota, and Kansas (Woodley 2001).

Figure 4.  

Cephalochrysa nigricornis. Photograph by Steve Nanz, used with permission.

Gowdeyana punctifera (Malloch, 1915) (Stratiomyidae) is widespread in eastern North America and occurs from Massachusetts south to Alabama, west to South Dakota, Wyoming, Utah, and Morelos and Sinaloa, Mexico (Woodley 2001).

Sargus decorus Say, 1824 (Stratiomyidae) (Fig. 5) is widespread in North America and occurs from Quebec and Ontario, south to Georgia, west to Yukon, British Columbia, Washington, and California (Woodley 2001).

Figure 5.  

Sargus decorus. Photograph by Phil Huntley-Franck, used with permission.

Callopistromyia annulipes Macquart, 1855 (Ulidiidae) is widespread in North America and has been reported from Maine south to Louisiana, west to Washington (Kameneva and Korneyev 2005).

Rachicerus obscuripennis Loew, 1863 (Xylophagidae) (Fig. 6) is the only species of the genus in the eastern United States with pectinate antennae; it is found in wooded areas and has been recorded from New York south through Florida, west to Minnesota, Nebraska, Missouri, and Kansas (Fig. 7) (Webb 1984).

Figure 6.  

Rachicerus obscuripennis. Photograph by Stephen A. Marshall, used with permission

Figure 7.  

Rachicerus obscuripennis collection localities, including those from Loew 1863, Snow 1903, Leonard 1930, Webb 1984; Bugguide localities from Coin 2006, Hatfield 2009, Bentley 2014).


It is unsurprising that only one of the twenty species of Asilidae was newly recorded in Arkansas as author Barnes has been studying robber flies in the state for over a decade. However, that such a distinctive species as Rachicerus obscuripennis has been known from Missouri since 1901 but is just now reported from neighboring Arkansas illustrates how poorly surveyedsome groups are in the state. This is in line with previous publications in this series, which also reported species previously unrecorded in Arkansas, some of which are quite distinctive (Skvarla et al. 2015, Skvarla et al. 2016b, Skvarla et al. 2016a).

Previous publications have utilized social media and citizen science websites such as Facebook, Flickr, and Bugguide to discover new species (e.g., Winterton et al. 2012, Otto et al. 2014, Gonella et al. 2015) and expand the known range of described species (e.g., Pérez-Hidalgo et al. 2011, Skvarla et al. 2015). The photographs that depict nectivory in Lygistorrhina sanctaecatharinae highlight the potential importance of such websites in of the study of natural history and illustrate how they can connect researchers with photographs of behavior in species that are rarely seen alive.


We thank Chris Haryley, Gayle and Jeanell Strickland, Steve Nanz, Phil Huntley-Franck, and Stephen A. Marshall for giving permission to use their photographs and Lisa Bentley, Patrick Coin, and M.J. Hatfield for posting their photographs of R. obscuripennis to Bugguide and granting permission to use their locality data. This project and the preparation of this publication were funded in part by the State Wildlife Grants Program (Grant # T-45) of the U.S. Fish and Wildlife Service through an agreement with the Arkansas Game and Fish Commission.


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