A Survey of Tiger Beetles (Coleoptera: Cicindelidae)

in the Black Hills of South Dakota

 

Scott A. Weins

Elizabeth M. Krueger

 

 

Introduction

Most taxonomists place tiger beetles in the family Cicindelidae, closely related to the family Carabidae or ground beetles (Graves and Brzoska 1991).  Cicindelidae is represented by 2 genera and 24 species within South Dakota.  Both genera and 17 species have been recorded in the Black Hills of South Dakota.  All Black Hills species are ground-dwelling predators.  Most are diurnal, fast runners, and good fliers.  Amblycheila is the single exception, being strictly nocturnal and flightless.  Some other species, though primarily diurnal, can be attracted to artificial lights.

The Black Hills are one of 11 physiographic regions found in South Dakota (Van Bruggen 1985).  The Black Hills are further divided into 6 geomorphic regions (Larson and Johnson 1999) and 73 Ecological Land Units (USDA Forest Service 1980).  Annual precipitation varies from 71 cm in the higher northern hills to 33 cm in the southern foothills (Larson and Johnson 1999) and greatly influences vegetation dynamics from north to south.

The primary objectives of this survey are to identify and document the species of tiger beetles that occur in the Black Hills of South Dakota, discuss preferred habitats, and demonstrate temporal and spatial distributions.  Information recorded for each specimen includes identification of species, the reference used for identification, collection number, date and site of collection, air temperature at the time of collection, and the elevation, habitat type, and description of each collection site.  The data collected is combined with historical data and compared with recent literature to support our conclusions.  A key to the tiger beetles of the Black Hills is also included.

 

Methods

The study area consists of the South Dakota portion of the Black Hills, including parts of Butte, Custer, Fall River, Lawrence, Meade, and Pennington Counties.  The northern boundary of the study area follows the Belle Fourche River east from the Wyoming state line to Highway 79.  The eastern boundary follows Highway 79 from the Belle Fourche River to Interstate 90 at Sturgis, Interstate 90 from Sturgis to Highway 79 in Rapid City, Highway 79 from Rapid City to Highway 385, and Highway 385 from Highway 79 to Angostura Reservoir.  The southern boundary is the Cheyenne River from Angostura Reservoir to the Wyoming line.  The state line is the western boundary.

This area is approximately 145 km from north to south and 58 km from east to west.  Elevations range from 975 m at the edge of the prairie to 2207 m at Harney Peak. 

Surveys of adult tiger beetles were conducted 3 times at each of 16 sites throughout the study area.  The surveys began in April 2001 and ended early in October of the same year.  These sites represent various elevations, vegetation types, and geomorphology, as well as both xeric and riparian areas.  Specimens were collected with an insect net from open areas, trails, unvegetated streambanks, and lakeshores.  At each site, a transect 225-1300 m in length was surveyed.  A black light was used to attract beetles at night at 5 sites, mostly during July and August.  All species collected were identified using “Key to the Cicindela of Nebraska” (Carter 1989), and representatives of each species from each study site were preserved and later pinned in our display cases.  Duplicate species representatives were released. 

 

Description of Survey Sites

Sites are described from north to south.  Site descriptions are based on collection notes and characteristics of the Ecological Land Unit (ELU) where each site is located.  Detailed site maps are in Appendix A.

The McNenny Fish Hatchery (Lawrence County, ELU #35) is the northernmost site, located in the “Red Valley” that encircles the Black Hills.  The collection site is in the Opeche formation, which is characterized by red clay soils (Gries 1996).  Two spring-fed lakes are found on the site.  The transect runs from west to east on the north side of West Mirror Lake, then to the north along approximately 800 m of native-surface road closed to motorized vehicles.  Vegetation on the gently rolling prairie consists of grasses, forbs, cacti, yucca (Yucca glauca), and shrubs such as silver buffaloberry (Shepherdia argentea), interspersed with exposed patches of dense red clay soil.  Elevation ranges from 1100 to 1200 m. 

The Boundary Gulch site (Lawrence County, ELU #32) is at the edge of an area burned by wildfire approximately 15 years ago.  Habitat type is dry pine/oak.  The transect follows a trail along a ridgetop, with the burned area to the west and fairly dense, mature ponderosa pine (Pinus ponderosa) to the east.  The burned area is now vegetated with shrubby bur oak (Quercus macrocarpa) over a variety of grasses and forbs.  Soil is generally a channery and sandy loam, with a sand inclusion at the end of the trail.  Elevation is approximately 1490 m. 

The Sturgis Bureau of Land Management (BLM) site (Meade County, no ELU #) is part of the forested hogback ridge that surrounds the Black Hills.  The transect follows a closed-off jeep trail approximately 480 m through a large open meadow of grass and forbs, terminating in a mature, closed-canopy, dry pine/oak site.  Soils are sandy loam to pure sand.  Elevation is 1090 m.

Steamboat Rock (Lawrence County, ELU #25) is a dry ponderosa pine site at an elevation of 1370 m.  The transect follows an old logging road about 480 m through a forested stand with about a 50% overstory canopy cover.  About 80% of the road surface area is vegetated, primarily with grasses and forbs.  Soils are channery and silty loam. 

The Keough Draw site (Lawrence County, ELU #23) is a primitive road running about 800 m up the moist drainage.  The north end of the transect is in a moist, open meadow with willows (Salix spp.) along the stream.  The transect then enters a forested area with white spruce (Picea glauca) on the north-facing slope and ponderosa pine on the south-facing slope.  Soils are loamy and densely vegetated, although the road bed is rocky with little vegetation.  The elevation is 1795 m. 

The Black Fox site (Lawrence County, ELU #23) follows an old logging road through about 600 m of open meadow at the bottom of a draw.  The adjacent north-facing slope is densely forested with white spruce, while ponderosa pine dominates the south-facing slope.  Substrate ranges from silty loam soil to rocky limestone.  Elevation at this site is 1830 m.

The Hayward site (Pennington County, ELU #07) is primarily a riparian site.  The transect crosses Iron Creek and follows a heavily used dirt road a short distance through ponderosa pine and mixed hardwoods, ending at the open banks of Battle Creek.  Canopy cover in the forested area is up to 75%.  There is very little vegetation on the road.  The creek banks are heavily vegetated, but mud banks become exposed in mid- to late summer when the water level drops.  Soils are sandy/silty with bits of mica.  The elevation is 1150 m. 

Deerfield Lake (Pennington County, ELU #08) is a high-elevation reservoir.  The transect runs 400 m along a foot trail through upland meadow with scattered ponderosa pine, then follows the rocky beaches of the reservoir for another 400 m.  Meadow vegetation is fairly dense, dominated by grasses such as little bluestem (Schizascyrium scoparium) and timothy (Phleum pretense) and forbs such as western yarrow (Achillea millefolium) and prairie smoke (Geum triflorum).  Water levels were high in 2001, with little exposed bank until late August.  The elevation is 1830 m.  

Moon Campground (Pennington County, ELU #22) is, at 1920 meters, the highest of the 16 sites.  The transect follows an ATV trail approximately 600 m through a mature ponderosa pine stand.  About 60% of the trail is vegetated with grasses and forbs.  Forest overstory cover is 65%.  Soil is a sandy loam.  The trail is open to motorized vehicles, but is not heavily used.

Bismark Lake (Custer County, ELU #01) is near the exposed granite core area of the Black Hills.  The transect follows a road about 900 m through ponderosa pine/common juniper (Juniperis communis) forest.  The trail is rocky and has varying vegetation densities.  Overstory forest canopy cover ranges from 20% to 60%.  Collections could not be made along the lake, since water levels were high and unvegetated bank was not exposed.  Elevation is 1580 m. 

The Schenk Canyon site (Custer County, ELU #21) is a dry ponderosa pine site in the southern Black Hills.  The transect follows a logging road approximately 1400 m through open pine forest.  There is little vegetation on the trail, and overstory forest canopy cover averages 20%.  Soils are channery and silty loam with some rocky areas.  The 486-hectare Rogers Shack wildfire burned within 400 m of this site during the survey period.  The elevation of this site is 1400 m.

Rifle Pit Road (Custer County, ELU #02) runs through upland meadow habitats.  This dry meadow includes islands of ponderosa pine.  Grasses and forbs dominate the area.  Soils are loam, rocky in places. The elevation of this site is 1400 m.

The Cold Brook site (Fall River County, ELU #40), like McNenny, is in the Red Valley.  The transect follows a foot path along an archery range and passes through open, eroded red clay banks and gypsum formations.  The site has an open canopy of ponderosa pine with an understory of grasses, forbs and low-growing shrubs.  Collections were also made along foot trails near Cold Brook reservoir. The elevation at this site is 1090 m.

Whitney Preserve (Fall River County, ELU #51) is held by The Nature Conservancy.  The transect follows a lightly graveled, little-used road on clay and sand through a dry upland meadow with scattered islands of ponderosa pine.  Transect length is approximately 1200 m. Grass and forbs are the dominant vegetation.  Elevation at this site is 1340 m.

The Cheyenne River site (Fall River County, ELU #70) consists of rocky sandbars in the river and a sandy, sparsely vegetated area along the bank.  The transect is less than 400 m long.  Elevation here is 975 m.

The Angostura Reservoir site (Fall River County, ELU #50) is in the short-grass prairie/sage steppe habitats of the southern Black Hills.  The transect follows a dirt road along the west side of the reservoir for about 1100 m.  Recreational traffic is heavy during summer and fall.  Vegetation is primarily grasses and forbs, with some shrubs.  Much of the vegetation consists of weedy species such as crested wheatgrass (Agropyron cristatum), and vegetation cover is very dense and continuous.  Collecting also took place along the lakeshore, although not until September when water levels dropped.  Elevation is 975 m.

 

 

Results and Discussion

 

Survey Results

A total of 140 specimens were collected within the study area during the summer of 2001.  We also collected a total of 82 specimens within the study area during the summers of 1999 and 2000.  These 222 specimens represent a total of 16 species.  Historical records include an additional 2 species we did not find, as discussed below.  Data on representative specimens was added to a database of all known tiger beetle records from the Black Hills area (Backlund et al. 2001).  Where we collected more than one individual of a given species at a site, only one was entered into the database.  The final database contains 232 records, representing 2 genera and 19 species.   

Two species historically reported from the Black Hills were not included in the database.  The sole Black Hills record of C. hirticollis was made from the Tinton area in 1964 (Glassel et al. 1964).  This species generally inhabits the beds of moist, sandy creeks and rivers (Carter 1989).  Habitat in the Tinton area, however, is dry pine/aspen forest with a few small, mostly intermittent streams nearby.  The lack of appropriate habitat and the evidence of strong dispersal ability (Larochelle and Larivière 2001) lead us to believe that there is probably not a population of this species in the study area.  Knisley and Schultz (1997) reported wind events as having an effect on dispersal of certain tiger beetle species.  This may have been the cause of the 1964 record, as C. hirticollis has been reported from northern Nebraska and Martin, South Dakota.

C. terricola cinctipennis has been reported twice in the study area:  once in the Custer area (Gilbertson 1929) and once in Cascade Valley (McIntosh 1928).  Larochelle and Larivière (2001) report this species to inhabit grassland prairies, roads, dry creek beds, and edges of ponds, creeks and rivers.  Carter (1989) indicates that soil salinity and alkalinity may affect distributions of this species.  Nebraska records show that C. t. cinctipennis is found in less saline habitats than other types of C. terricola.  Based on this information, it appears that Cascade Valley does have suitable habitat for this species, though the area around Custer probably does not.  We surmise that since there is appropriate habitat, there was or possibly still is a population of this species somewhere in the far southern Black Hills.  Dispersal from populations in the Nebraska panhandle would also be possible.  Further surveys are needed to determine the status of this species.

For the purposes of this report, 2 genera and 17 species will be considered to inhabit the Black Hills area.

Table 1 shows species observed at each survey site.

 

   Table 1.  Species observed by survey site