Arthropods of Steel Creek, Buffalo National River, Arkansas. III. Heteroptera (Insecta: Hemiptera)

Abstract Background This is the third 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 using twelve trap types – Malaise traps, canopy traps (upper and lower collector), Lindgren multifunnel traps (black, green, and purple), pan traps (blue, purple, red, white, and yellow), and pitfall traps – and Berlese-Tullgren extraction of leaf litter. New information We provide collection records for 54 species of Heteroptera, 11 of which were new state records for Arkansas: (Aradidae) Aradus approximatus, Aradus duzeei, Aradus ornatus, Neuroctenus elongatus, Neuroctenus pseudonymus, Notapictinus aurivilli; (Cydnidae) Sehirus cinctus; (Lygaeidae) Nysius raphanus; (Miridae) Prepops insitivus; (Reduviidae) Zelus tetracanthus; (Rhyparochromidae) Kolenetrus plenus.


Introduction
The Ozarks are a biodiversity hotspot that has been relatively understudied compared to similar areas, such as the Southern Appalachians (Skvarla et al. 2015). This is the third in a series of papers that detail the arthropod fauna collected during a nine month survey conducted in the Boston Mountain subsection of the Ozarks near the Buffalo National River in northwest Arkansas and highlight species newly recorded from the state (for select Coleoptera see Skvarla et al. 2015 and for "Symphyta" see Skvarla et al. 2016). The geologic and biogeographic history of the region and collection methodology of the study were covered in detail by Skvarla et al. 2015Skvarla et al. . et al. 2014. Insect escape was impeded by the addition of unscented, hypoallergenic 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 to easily identifiable levels (generally family, occasionally order or genus) 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 in 2 mL microtubes in 70% ethanol.
Specimens were identified with the use of published keys (Table 1). Crasswell 2014) was consulted when the authors were unfamiliar with Heteroptera-specific morphological terms.
Aradus approximatus (Aradidae) is known from Quebec south to Georgia and west to Indiana and Mississippi (Froeschner 1988a). The specimens reported here represent a western range extension.
Aradus duzeei (Aradidae) is known from Quebec and Ontario south to Virginia and west to Missouri (Froeschner 1988a).
Aradus ornatus (Aradidae) is known from New York and Pennsylvania, south to Georgia, and west to Indiana (Froeschner 1988a (Froeschner 1988a).
Notapictinus aurivilli (Aradidae) is known from Florida, Georgia, and Louisiana (Froeschner 1988a, Taylor andGill 2009). The specimens reported here represent a northern range extension and the first inland records away from Gulf Coastal states.

Sehirus cinctus (Cydinidae) is widespread in North America and occurs from
Newfoundland and Quebec south to Florida, west to California and south into Mexico (Froeschner 1988b). It has been previously recorded from all states surrounding Arkansas and its occurrence in the state is unsurprising.
Nysius raphanus (Lygaeidae) is widespread, being found in North America from Ontario, south to Florida, west to British Columbia, California, and New Mexico; it is also known from Mexico and the West Indies (Ashlock and Slater 1988). It has been previously recorded from Missouri, Kansas, and Texas and its occurrence in Arkansas is unsurprising.
Preopos insitivus (Miridae) is widespread in eastern North America, from New Hampshire and Ontario south to Florida, and west to Colorado; it has previously been reported from Missouri (Henry and Wheeler 1988 (Slater and Baranowski 1978, Ashlock and Slater 1988, Scudder 1993, Maw et al. 2000. The specimens reported here likely represent a disjunct population that is restricted to the Ozarks or Interior Highlands. Xestocoris nitens (Rhyparochromidae) is known from Quebec, Nova Scotia, and Ontario south to Virginia, west to Michigan, Missouri, andNebraska (Ashlock andSlater 1988, O'Donnell 2007). Scudder 2010 was the first to record it from Arkansas (Logan County). An unpublished specimen of X. nitens, collected in Hempstead County on 5 February 1954 is housed in the University of Arkansas Arthropod Museum and a second unpublished Xestocoris from Pulaski County, which is likely X. nitens, is housed in Texas A&M University Insect Collection (Quinn 2015).
Acalypta susanae (Tingidae) is known from two specimens collected from Mt. Magazine in Arkansas (Allen et al. 1988). The specimens reported here extend the species range northwest into the Boston Mountains and increase the number of specimens in collections. Nymphs, which are undescribed for this species, were collected, although a formal description of immature lifestages is beyond the scope of this work.

Discussion
The relative abundance of Acalypta susanae (33 specimens) collected in this study, when compared to the number of previously known specimens (2), is striking. The species is obviously more widespread than previously thought, but it is unclear without additional sampling effort whether it is locally abundant and the sampled site was particularly good habitat or if they are abundant throughtout their range. As the species is a rather distinctive tingid and easily identified, future leaf litter studies in the Interior Highlands and surrounding area should be observent for additional specimens.
Kolenetrus plenus is an interesting species becuase the it has an apparently disjunct range and is restricted to cool, xeric fields in mountainous areas. The specimens reported here are not totally unexpected as the Interior Highlands is the only mountainous region that occurs between the eastern populations in North Carolina and western and southern populations in Arizona and Mexico.
Most of the species newly recorded from Arkansas are widespread in eastern North America and many are known from states that border Arkansas. While their presence in the state is therefore unsurprising, the fact that have have not been previously recorded highlights how under surveyed the state is, especially compared with other biodiversity hotspots.

Author contributions
Michael Skvarla performed all responsibilities associated with collecting the specimens, including trap maintenance and sample collection; sorted samples; and prepared the manuscript. Danielle Fisher sorted samples and coarse-sorted specimens to higher taxa (order/family). Ashley Dowling supervised the lab in which Skvarla and Fisher performed the work, provided financial support by securing funding, and commented on the manuscript prior to submission.