Surveys of Arkansas Dung Beetles (Coleoptera: Scarabaeidae and Geotrupidae): Phenologies, Mass Occurrences, State and Distributional Records
Fiene, Justin G., Connior, Matthew B., Androw, Robert, Baldwin, Brian, McKay, Tanja, The American Midland Naturalist
We present the results of an 18 mo survey of the seasonal activity and species composition of dung beetles (Scarabaeidae: Scarabaeinae and Aphodiinae and Geotrupidae: Geotrupes) from a cattle pasture on Crowley's Ridge, Arkansas, and of 17 additional surveys, at various localities and habitats across Arkansas. Collections at the cattle pasture comprised 236,880 beetles, representing 22 species. Labarrus pseudolividus Balthasar comprised 97.7% of the total trap catch, with the majority being collected in Jun., Jul. and Aug. 2007 which involved two separate mass occurrences during that time. From all surveys, we documented 22 state records, of which Colobopterus erraticus (Linnaeus) and Onthophagus taurus (Schreber) represented subtle range extensions to their known distributions, while the remaining 20 species were projected to occur in Arkansas. A checklist, distributional record and bibliography of the 64 species of dung beetles that are now known to occur in Arkansas are presented.
By fragmenting and burying excrement, dung beetles (Scarabaeidae: Scarabaeinae and Aphodiinae and Geotrupidae) are an important ecological component in both natural and artificial ecosystems (Bornemissza, 1960; Fincher, 1981; Nichols et al., 2008). Therefore, there is general interest among ecologists and cattle producers in research that aims to conserve and manage these beneficial beetles. Towards this end, to survey dung beetles and catalog their phenologies within a geographic region are the first necessary efforts. Surveys of Scarabaeoidea, which include dung beetles, have been conducted in a number of states (see Kriska and Young, 2002 for review; Riley and Wolfe, 2003). For example, in Texas, the diversity of dung beetles collected in each of seven regions ranged from 44-91 species (Riley and Wolfe, 2003). Limited niche specific surveying has been done in Arkansas (e.g., Ozark pocket gopher, Geomys hirsarius ozarkensis Elrod, Zimmerman, Sudman & Heidt, burrows, Kovarik et al, 2008). For the six physiographic regions in Arkansas, only 43 species of dung beetles have been documented to date. Thus, there seemed to be potential to increase the known dung beetle fauna of Arkansas through further surveying efforts of both natural (e.g., forests) and artificial (e.g., cattle pastures) habitats.
We surveyed dung beetles at various localities and habitats across Arkansas to document the dung beetle species and their distributions within the state. The primary study presents the results of an 18 mo survey of dung beetles on Crowley's Ridge. This study is important because it was the first effort to identify dung beetles on Crowley's Ridge in Arkansas, while also being the first survey to document the phenologies and species composition of an assemblage of pasture-inhabiting dung beetles in all of Arkansas.
MATERIALS AND METHODS
Primary locality description. - The primary study was conducted at the Arkansas State University (ASU) Farm Complex in Jonesboro, Craighead County, Arkansas. The loessal soil type at the ASU Farm Complex is classified as Loring-Grenada-Henry and is characterized as deep, well- to poorly-drained and slowly permeable (Crow, 1974). The ASU Farm Complex is located on Crowley's Ridge, which is an area of rolling hills that rises abruptly 60-90 m from the flat delta land surrounding it. The Ridge ranges from 1.6 to 16 km wide and runs from southern Missouri to Helena, Arkansas (240 km-long), encompassing portions of Clay, Greene, Craighead, Poinsett, Cross, St. Francis and Lee Counties. Crowley's Ridge is an erosional remnant of a higher plain from which the present alluvial plain was carved during the Pleistocene interglacial periods when the Mississippi River meandered to the west of the ridge and the Ohio River to the east (Crow, 1974). The vegetation that occurs on Crowley's Ridge is more closely related to the flora (e.g., tulip tree-oak forests) of Tennessee than to the oak hickory forests of the Ozarks, indicating that the biota of Crowley's Ridge had a more recent connection with the Tennessee biota than with the biota of the Ozark/ Ouachita area in Arkansas (Robison and Allen, 1995). …