The Great Lakes Entomologist Volume 53 Numbers 3 & 4 - Fall/Winter 2020 Numbers 3 & Article 4 4 - Fall/Winter 2020 December 2020 A Synopsis of the Flat Bugs (Heteroptera: Aradidae) of Michigan Daniel R. Swanson University of Illinois at Urbana-Champaign, [email protected] Follow this and additional works at: https://scholar.valpo.edu/tgle Part of the Entomology Commons Recommended Citation Swanson, Daniel R. 2020. "A Synopsis of the Flat Bugs (Heteroptera: Aradidae) of Michigan," The Great Lakes Entomologist, vol 53 (2) Available at: https://scholar.valpo.edu/tgle/vol53/iss2/4 This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. For more information, please contact a ValpoScholar staff member at [email protected]. A Synopsis of the Flat Bugs (Heteroptera: Aradidae) of Michigan Cover Page Footnote The majority of this study was carried out during my time in the University of Michigan Museum of Zoology, Ann Arbor, Michigan. I thank Mark O’Brien (UMMZ) for his sponsorship regarding loaned material as well as his constant support in my entomological pursuits. I am grateful to Gary Parsons (MSUC) for accommodating several visits to the collection in East Lansing to study the material under his care. I was able to photograph the specimen of Aradus uniannulatus from the American Museum of Natural History, New York, under a Collections Studies Grant awarded to me, and I thank David Grimaldi for sponsoring my visit and Toby Schuh and Ruth Salas for allowing me to study specimens in the Hemiptera Collection. I also thank Robert Zuparko (CAS) for information regarding a Parshley’s paratype. I also express my appreciation to two anonymous reviewers, whose comments greatly improved the manuscript. This peer-review article is available in The Great Lakes Entomologist: https://scholar.valpo.edu/tgle/vol53/iss2/4 Swanson: Michigan Aradidae Synopsis 2020 THE GREAT LAKES ENTOMOLOGIST 83 A Synopsis of the Flat Bugs (Heteroptera: Aradidae) of Michigan Daniel R. Swanson Department of Entomology, University of Illinois at Urbana-Champaign, 320 Morrill Hall, 505 South Goodwin Avenue, Urbana, IL 61801 Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 1816 South Oak Street, Champaign, IL 61820-6960 urn:lsid:zoobank.org:author:1F74F4E6-DA35-4A90-8572-EDC8F6660B43 https://orcid.org/0000-0002-0830-2383 (e-mail: [email protected]). Abstract An overview of the 28 species of Aradidae found in Michigan is presented, along with an identification key, distribution maps, and relevant literature. Eleven new state records are presented for the following species: Aradus approximatus Parshley, Aradus duzeei Bergroth, Aradus falleni Stål, Aradus insolitus Van Duzee, Aradus intectus Parshley, Aradus montanus Bergroth, Aradus proboscideus Walker, Aradus shermani Heidemann, Aradus uniformis Heidemann, Quilnus niger (Stål) (all Aradinae), and Neuroctenus simplex (Uhler) (Mezirinae). Keywords. true bugs, faunistics, distribution, checklist Aradidae, commonly called flat bugs or ruficeps Hussey, 1953, was described based bark bugs, is a family of strongly flattened on a single specimen from Michigan. mycophagous true bugs comprising 126 In an effort to compile the knowledge species in 11 genera in the United States and expose the diversity of these cryptic in- (updated from Froeschner 1988). These in- sects are cryptic both in habitus and habitat, sects, I herein present the results of my study having a granular integument that adheres of the Aradidae of Michigan, my seventh bits of substrate and being found most often synoptic family-level contribution studying under the bark of dead or dying trees or logs. the heteropteran fauna of the state. They also tend to be slow-moving insects, Materials and Methods. Methods and this habit, coupled with habitus and parallel previous installments of this series habitat, can make them difficult to see, even (Swanson 2011, 2012a, b, 2013, 2015, 2016): when (unknowingly) encountered. Thus, The aradid holdings of the two major despite being a diverse group, aradids are uncommonly found, especially compared to university collections in southern Michigan other Heteroptera, and this phenomenon is were examined. County records were com- apparent in the holdings of entomological piled, identification keys were modified, and research collections. the existing natural history information, both Michiganian and extralimital, was The group has never been treated for summarized. Notes on additional species of Michigan, although O’Brien’s (1983, 1988) potential relevance to Michigan follow the lists of literature concerning the terrestrial primary species accounts. arthropods of Michigan contain sources with a few records of Aradidae. Townsend The identification of the 282 specimens (1890) and Hussey (1922) contributed to included in this study was rendered or the knowledge of the Aradidae of Michigan, confirmed by the author, and all specimens each having catalogued the Heteroptera reside in one of the collections listed below found in the vicinity of Constantine, Saint unless otherwise noted. Collection dates indi- Joseph County and Berrien County, respec- cate the earliest and latest adults examined tively. Additionally, Pettit (1901) recorded and refer specifically to specimens collected an Aradus sp. from Munising Junction in Michigan. In the instances where provid- (Alger County), and Adams (1909) recorded ed, label data are not transcribed verbatim, a single species of Aradus from Isle Royale but complete locality information is includ- (Keweenaw County). One species, Aradus ed. Any additions, changes, or interpretive Published by ValpoScholar, 2020 1 The Great Lakes Entomologist, Vol. 53, No. 2 [2020], Art. 4 84 THE GREAT LAKES ENTOMOLOGIST Vol. 53, Nos. 3–4 Figure 1. The counties of the State of Michigan. elements provided by the author are shown ever, comparison with the plates will not in brackets. Locations of Michigan counties serve as a replacement for keying out from which specimens were collected are specimens. depicted in Fig. 1. In the keys, certain characters are The habitus plates (Figs. 2–4) are occasionally set apart using brackets. These intended to provide a visual reference for brackets signify that the contrasting charac- the diversity found in Michigan. Several ter is not in that particular couplet but ap- forms are distinctive in general habitus or pears in one of the immediately successive particular morphological characters. How- couplets attained through the opposite lead. https://scholar.valpo.edu/tgle/vol53/iss2/4 2 Swanson: Michigan Aradidae Synopsis 2020 THE GREAT LAKES ENTOMOLOGIST 85 Figure 2. Aneurinae and Mezirinae of Michigan, dorsal habitus. Regarding host records, I have com- Lansing, Michigan (MSUC); and Universi- piled those previously mentioned in the ty of Michigan Museum of Zoology Insect literature for the aradid species found in Collection, Ann Arbor, Michigan (UMMZ). Michigan (Table 2), with a few caveats. First, I have reduced records of trees to Results and Discussion genus-level only; this means that tree spe- cies might be listed in the original citation. Family ARADIDAE Spinola, 1837 Second, I have included only tree genera Flat bugs are generally unmistakable that occur in Michigan. For example, in ad- in their oval to rectangular, strongly-flat- dition to the five genera listed in the table, tened habitus. Additionally, members in the Aneurus fiskei Heidemann, 1904a also has Nearctic may be characterized by a short, been recorded from Oxydendrum [arboreum stout four-segmented rostrum, absence of (L.) DC.] (Blatchley 1926); yet, this record ocelli, two-segmented tarsi, and a rough or is herein excluded, because sourwood does granular integument (Slater and Baranows- not occur in Michigan. In the case where an ki 1978, Schuh and Slater 1995). Aradids aradid has been recorded from a tree species also possess distinctive coiled mandibular absent in Michigan but with congeners that stylets, thereby allowing long structures to are present in the state, I have included the be stored in a small head capsule (Spooner generic level record. For example, Quilnus 1920, Lee and Pendergrast 1976). Aradids niger (Stål, 1873) has been recorded from are usually found under the bark or on longleaf pine (Pinus palustris Mill.) (Parsh- fungus associated with dead or dying trees ley 1921), and even though longleaf pine or in leaf litter. However, some members of does not occur in Michigan, Pinus is still the family are found in the nests of birds marked in the table, regardless of whether and rodents, as well as termites (Kormilev records for other Pinus spp. exist for Q. and Froeschner 1987, Schuh and Slater niger (they do!). Presence of tree genera 1995). Some species are gregarious (Cassis and species in Michigan was assessed using and Gross 2002), with many individuals of Barnes and Wagner (2004). The compilation various life stages found in groups under a of this table should not be construed as a single patch of bark. Others go beyond simple definitive statement on the hosts of aradids. gregariousness: McClure (1932), Takahashi On the contrary, there is little evidence to (1934), and Taylor (1988a) described paren- suggest that aradids are restricted to par- tal care in three different aradid species. ticular species of trees, and many of these However, it is not known how widely this records represent at best (1) trees that can phenomenon occurs in the family. Strid- host fungal species consumed by aradids ulation also is documented in the group or (2) incidental captures, especially if (Bergroth 1892, Usinger 1954). Leston (1955) occurring during seasonal flights. Lastly, generally described the male and female records of fungal hosts, being much more genitalia. Vásárhelyi (1986) investigated sparse (and perhaps more meaningful) are the utility of the pretarsus as a taxonomic listed under the species accounts. character. Schuh and Slater (1995) provided Collections are designated as follows: a concise general family-level treatment in Daniel R.