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Aquatic and Semiaquatic Beetles of the Great Smoky Mountains National Park (Coleoptera: Dytiscidae, Gyrinidae, Haliplidae, Helophoridae, Hydraenidae, Hydrochidae, Hydrophilidae, and Noteridae)
Guenter A. Schuster, Christopher A. Taylor, and John Johansen

Southeastern Naturalist, Volume 7, Number 3 (2008): 505–514

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2008 SOUTHEASTERN NATURALIST 7(3):505–514 Aquatic and Semiaquatic Beetles of the Great Smoky Mountains National Park (Coleoptera: Dytiscidae, Gyrinidae, Haliplidae, Helophoridae, Hydraenidae, Hydrochidae, Hydrophilidae, and Noteridae) Charles L. Staines1,* and Adriean J. Mayor2 Abstract - Aquatic and semiaquatic beetles in the families Dytiscidae, Gyrinidae, Haliplidae, Helophoridae, Hydraenidae, Hydrophilidae, and Noteridae of the Great Smoky Mountains National Park (GSMNP) were sampled from 2003 to 2006. Current and historic literature as well as the insect collections at GSMNP, Illinois Natural History Survey, Smithsonian Institution, and University of Tennessee were examined for GSMNP records. This is the first comprehensive effort at surveying the aquatic and semiaquatic beetles of GSMNP. A total of 115 species were recorded: 46 Dytiscidae, 7 Gyrinidae, 5 Haliplidae, 2 Helophoridae, 2 Hydraenidae, 2 Hydrochidae, 49 Hydrophilidae, and 2 Noteridae. Eighty species are reported from GSMNP for the first time. Hydaticus aruspex Clark, Hydrocolus defl atus, H. paugus, Liodessus affinis (Dytiscidae), and Dactylosternum abdominale (Hydrophilidae) are reported from Tennessee for the first time. Introduction The Great Smoky Mountains National Park (GSMNP) is located in North Carolina and Tennessee. It covers over 210,000 ha and contains one of the largest tracts of forest in the eastern United States. The Park is one of the most species-rich temperate areas in the world and has been designated as an International Biosphere Reserve (Sharkey 2001). The Park’s location in the southeastern United States gives it a generally mild climate with abundant moisture and a long, warm season. The elevation gradient and topographic complexity of the Park have resulted in the development of numerous microclimatic and habitat types which nearly span the range of climatic and habitat types found in the entire Appalachian Mountain range. The All Taxa Biodiversity Inventory (ATBI) of GSMNP began in 1997 with the goal of documenting the diversity of organisms within the boundaries of the Park (Sharkey 2001). The ATBI involves both traditional and structured sampling protocols involving specialists, students, and volunteers sampling specific habitats. With the recognized importance of water bodies and wetlands in conservation planning and resource management efforts, the assessment of water beetle inventories can be considered an essential task. The purpose of this 1Department of Entomology, MRC 187, National Museum of Natural History, Smithsonian Institution, PO Box 37012, Washington, DC 20013-7012. 2Great Smoky Mountains National Park, 107 Park Headquarters Road, Gatlinburg, TN 37738. *Corresponding author - stainesc@si.edu. 506 Southeastern Naturalist Vol.7, No. 3 study was to collect and identify aquatic and semiaquatic beetles in seven families in as many habitats as possible in GSMNP and thereby contribute to a baseline inventory upon which to monitor and manage the Park’s natural resources. Carlton (2002) reported 35 aquatic beetle species from GSMNP, but the seven families targeted in this study have not been previously inventoried in a systematic way. Aquatic beetles have been proposed as bio-indicators of water quality and indicators overall biodiversity (Ribera and Forster 1993, Sánchez- Fernández et al. 2006). The group has not been used partly because of the misconception that they are difficult to identify, the incomplete knowledge of their biology and ecology, and the entrenched idea that water beetle distributions are more influenced by chance colonization rather than habitat suitability. However, the publication of reliable identification aides and a greater understanding of their biology now make this group more acceptable to natural area managers. Methods This survey focused on developing an inventory of seven families of aquatic and semiaquatic beetles in GSMNP. Sampling methodology was not designed to address questions of abundance, biodiversity, or habitat quality. Directed sampling was conducted from May to August in 2003 to 2006. Samples were generally taken in readily accessible portions of the Park. Techniques used were aquatic nets (D-frame), fl oatation (see Staines and Staines 2005), visual survey of dung and decaying organic matter, and 15- watt black lights. The primary focus was on the undersampled vernal pools, ditches, fl ooded meadows, and ponds. In small to medium-sized ponds, sampling was often done at various points around the entire perimeter. In larger bodies of water, only the shallower areas were sampled. No formal attempt was made to sample for a specific time period. Volunteers and science educators were trained in survey techniques and contributed in the number of sites surveyed. Other researchers conducting aquatic insect inventories provided specimens from their work that focused primarily on streams. Specimens of a representative sample of the material found at each site was collected and used for identification. Structured sampling efforts consisted of two Malaise/fl ight intercept traps, ten pitfall traps, and two Lindgren funnel canopy traps at eleven sites (Fig. 1). These sites were selected to represent a cross-section of habitat types found in GSMNP (see Petersen et al. 2005 for detailed site descriptions). The pilot structured sampling project was conducted from October 2000 to October 2002. Traps were run year round and emptied biweekly. Samples from the structured sampling are located at Louisiana State University; aquatic and semiaquatic beetles from sorted samples were identified. Current and historic literature was examined for GSMNP records. The insect collections at GSMNP, Illinois Natural History Survey, Smithsonian Institution, and University of Tennessee were examined for GSMNP records. 2008 C.L. Staines and A.J. Mayor 507 Figure 1. Location of the eleven structured ATBI survey sites. 508 Southeastern Naturalist Vol.7, No. 3 Given the limited funding and large geographical area, few locations were sampled intensively. Most sites were visited one time. Our focus was on the distribution of species rather than their abundance or diversity, which allowed us to use a variety of sampling techniques at most sites. While some methods are more effective in capturing aquatic and semiaquatic beetles, no single method is efficient for all species. By using several methods we improved our chance of detecting all species present. We chose this sampling approach with the understanding that our results provide preliminary estimates, not definitive answers. Results We surveyed a total of 255 sites and collected 109 species; there are six additional species reported from the literature which brings the total number of species from GSMNP to 115. These include 46 Dytiscidae, 7 Gyrinidae, 5 Haliplidae, 2 Helophoridae, 2 Hydraenidae, 2 Hydrochidae, 49 Hydrophilidae, and 2 Noteridae (Appendix 1). Eighty species are new records for the Park, and five species are new records for the State of Tennessee. Voucher specimens of each species collected by the authors are deposited in the GSMNP insect collection. In order to protect rare organisms found in many of the surveyed habitats, summary locality data is intentionally general, but more precise locality data are included in the GSMNP database. Significant Records Dytiscidae Agabetes acuductus (Harris) is a seldom collected woodland pool species found among dense leaf litter (Spangler and Gordon 1973). Park specimens were taken in temporary ponds from March to July at Cades Cove. Hydaticus aruspex Clark is most commonly found in permanent ponds with deep detritus and emergent aquatic plants, but occurs in a wide variety of aquatic habitats (Hilsenhoff 1993). This species is found from Newfoundland and Labrador west to British Columbia and Alaska, extending south to Pennsylvania, Missouri, Colorado, and northern California (Larson et al. 2000). Park specimens were taken in temporary pools from July to September at Cades Cove (Tennessee). New state record. Hydrocolus defl atus (Fall) has been found in spring seepages, swamps, and at lights (Ciegler 2003). This uncommonly collected coastal species is known from New York to Florida, extending up the Mississippi River basin to Illinois (Larson et al. 2000). Park specimens were taken in temporary pools and seeps in May and June at Cades Cove and Sugarlands (Tennessee). New state record. Hydrocolus paugus (Fall) has been found among moss, in dense emergent vegetation, and in debris along the margins of small pools, ponds, and springs (Larson et al. 2000). This species is known from Newfoundland west 2008 C.L. Staines and A.J. Mayor 509 to Alaska and British Columbia, extending south into the New England states, Iowa, Colorado, and Utah (Larson et al. 2000). Park specimens were taken in woodland pools in August in Cades Cove. New state record. Liodessus affinis (Say) has been found mostly in ponds, but is also collected along the banks of streams (Larson et al. 2000). This species is known from Newfoundland to Ontario and south to Virginia, Ohio, Illinois, and Indiana (Larson et al. 2000). Park specimens were taken in temporary ponds in May and June in Cades Cove. New state record. Hydraenidae Ochthebius contains 43 North American species. This genus is widespread except for the Appalachian Mountains (Perkins 2001). Our Ochthebius specimen does not key in Perkins (1980) and does not match the description of any species; it may represent a species new to science. A single specimen was taken in June at black light at Sugarlands (Tennessee). Hydrophilidae Dactylosternum abdominale (Fabricius) has been found in decaying organic debris (Smetana 1978). The species has been reported from Alabama, California, Florida, North Carolina, and Texas (Smetana 1978). A single specimen was taken in bear dung in May at Tremont (Tennessee). New state record. Sperchopsis tessellatus (Ziegler) is associated with fast-fl owing streams with sand or gravel bottoms; the most productive area for this species is under exposed roots at the margin of streams (Spangler 1961). A single specimen of this uncommon species was collected in April along Abrams Creek (Cades Cove). Discussion The major goal of the ATBI is to identify all forms of life within the borders of the Great Smoky Mountains National Park. Toward this end, this project has increased four-fold the number of species representing eight aquatic beetle families known from GSMNP (115 in 2006, up from 35 in 2003). The total number of species in GSMNP is probably higher, and species will be added to the Park list as the less accessible areas are inventoried. Due to sampling constraints, it is likely some cryptic species were also missed. Most of the species found in this study are taxa that are relatively widespread in occurrence. The only uncommon species collected were Agabetes acuductus, Hydroculus defl atus (Dytiscidae) and Sperchopsis tessellatus (Hydrophilidae). The Ochthebius species (Hydraenidae) is the first record of this genus from the Appalachian Mountains. There are few comparable Nearctic studies of aquatic beetles. Young (1955) reported 55 species in six families from springs in the Panhandle of Florida. Lillie and Hilsenhoff (1992) reported 38 species in five families on the Lower Wisconsin River. Chapman (1998) reported 145 species in seven families from a 10,327-km2 area in northeastern Ohio. Staines and 510 Southeastern Naturalist Vol.7, No. 3 Staines (2005) reported 42 species in three families from a 925-ha island in Maryland. Williams et al. (2007) reported 111 species in six of the families covered in this report from a 8672-ha military base in Ohio. One possible reason for the higher number of species found in the two Ohio projects is the greater number of lentic habitats available in that region. Most GSMNP aquatic habitats are lotic; the lentic habitats are concentrated in Cades Cove, Cataloochee, and Metcalf Bottoms areas, but only one of these habitats is a permanent pond, the rest are temporary pools and ponds. This study serves as a starting point for assessing the aquatic and semiaquatic beetle fauna of GSMNP and to monitoring future changes in the fauna. To aid in this work, webpages with habitus photographs, descriptions, and habitat preferences have been developed and posted for 114 of the species found in this survey (http://www.dlia.org). Acknowledgments We thank Michelle Prysby and the staff and students at the Great Smoky Mountains Institute at Tremont, Jan Ciegler, Susan L. Staines, Will Merritt, and M.J. Wetzel and R.E. DeWalt, Illinois Natural History Survey, for collecting specimens. We thank P. Lambdin (University of Tennessee), and C. Favet (Illinois Natural History Survey) for access to the collections under their care. Susan L. Staines provided editorial assistance. The manuscript was greatly improved by the comments of two anonymous reviewers. This project was funded in part by a grant from Discover Life in America. Publication costs were funded by National Science Foundation grant DEB-0516311 (C. Carlton and V. Bayless, Co-PI’s). Literature Cited Carlton, C.E. 2002. Beetles of the Smokies. Available online at http://www.agctr.lsu. edu/arthropodmuseum.smokieschecklist.htm. Accessed 16 December 2002. Chapman, E.G. 1998. Aquatic beetles (Insecta: Coleoptera) of northeastern Ohio (Haliplidae, Dytiscidae, Noteridae, Gyrinidae, Hydrophilidae, Psephenidae, Dryopidae, Elmidae, Ptilodactylidae). Ohio Biological Survey Miscellaneous Contribution No. 4. 117 pp. Ciegler, J.C. 2003. Water Beetles of South Carolina (Coleoptera: Gyrinidae, Haliplidae, Noteridae, Dytiscidae, Hydrophilidae, Hydraenidae, Scirtidae, Elmidae, Dryopidae, Limnichidae, Heteroceridae, Psephenidae, Ptilodactylidae, and Chelonariidae). Biota of South Carolina. Volume 3. Clemson University, Clemson. 207 pp. Hilsenhoff, W.L. 1993. Dytiscidae and Noteridae of Wisconsin (Coleoptera). II. Distribution, habitat, life cycle, and identification of Dytiscinae. Great Lakes Entomologist 26:35–53. Larson, D.J, Y. Alarie, and R.E. Roughley. 2000. Predacious Diving Beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with Emphasis on the Fauna of Canada and Alaska. NRC Press. Ottawa, ON Canada. 982 pp. Lillie, R.A., and W.L. Hislenshoff. 1992. A survey of the aquatic insects of the Lower Wisconsin River, 1985–1986, with notes on distribution and habitat. Wisconsin Department of Natural Resources Technical Bulletin 178. 43 pp. Perkins, P.D. 1980. Aquatic beetles of the family Hydraenidae in the Western 2008 C.L. Staines and A.J. Mayor 511 Hemisphere: Classification, biogeography, and inferred phylogeny (Insecta: Coleoptera). Quaestiones Entomologicae 16:3–554. Perkins, P.D. 2001. Family Hydaenidae Mulsant 1844. Pp. 228–232 In R.H. Arnett and M.C. Thomas (Eds.). American Beetles Volume 1: Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia. CRC Press. New York, NY. Petersen, M.J., C.R. Parker, and E. Bernard. 2005. The crane fl ies (Diptera: Tipuloidea) of Great Smoky Mountains National Park. Zootaxa 1013:1–18. Ribera, I., and G.N. Foster. 1993. Uso de Coleópteros acuáticos como indicadores biológicos (Coleoptera). Elytron 6:61–75. Sánchez-Fernández, D.,P. Abellán, A. Mellado, J. Velasco, and A. Millán. 2006. Are water beetles good indicators of biodiversity in Mediterranean aquatic ecosystems? The case of the Segura river basin (SE Spain). Biodiversity and Conservation 15:4507–4520. Sharkey, M.J. 2001. The All Taxa Biodiversity Inventory of Great Smoky Mountains National Park. Florida Entomologist 84:556–564. Smetana, A. 1978. Revision of the subfamily Sphaeridiinae of America north of Mexico (Coleoptera: Hydrophilidae). Memoirs of the Entomological Society of Canada 105:1–292. Spangler, P.J. 1961. Notes on the biology of Sperchopsis tessellata (Ziegler) (Coleoptera: Hydrophilidae). Coleopterists Bulletin 15:105–112. Spangler, P.J., and R.D. Gordon. 1973. Descriptions of the larvae of some predaceous water beetles (Coleoptera: Dytiscidae). Proceedings of the Biological Society of Washington 86:261–278. Staines, C.L., and S.L. Staines. 2005. The Dytiscidae and Hydrophilidae (Insecta: Coleoptera) of Eastern Neck National Wildlife Refuge. Maryland Naturalist 47:14–20. Wolfe, G.W. 1979. A zoogeographic and taxonomic analysis of the Dytiscidae of Tennessee with an emphasis on the pulcher-undulatus species group of Hydroporus (Adephaga: Coleoptera). Ph.D. Dissertation. University of Tennessee, Knoxville, TN. 153 pp. Young, F.N. 1955. A preliminary study of the water beetle fauna of Glen Julia Springs, Florida. Journal of the Florida Academy of Sciences 18:59–66. 512 Southeastern Naturalist Vol.7, No. 3 Appendix 1. List of species collected at Great Smoky Mountains National Park (GSMNP). Collecting methods (CM) is coded: Berlese (B), dip net (N), fl otation (F), black light (L), Malaise trap (M), hand (H), pitfall trap (PT), and fl ight intercept trap (FIT). Habitat is coded: ditch (D), dung (DU), fl ooded meadow (FM), light (L), pond (P), puddle (PU), river (R), seep (S), sewage lagoon (SL), sphagnum bog (SB), and temporary pool or pond (TP). Distribution is coded: Big Cove (BC), Big Fork (BF), Big Meadows (BM), Cades Cove (CC), Cataloochee (C), Chilogatee Creek (CH), Cosby (CO), Deep Creek (DC), Foothills Parkway (FP), Greenbrier (G), Indian Gap (IG), Metcalf Bottoms (MB), Noland Creek (NC), Oconaluftee (O), Purchase Knob (PK), Ravensford (R), Smokemont (SM), Sugarlands (S), Tremont (T), Twin Creek (TC), Smetana [1978] (Sm), and Wolfe [1979] (W). ? = unknown. Family Genus/species CM Habitat Distribution Dytiscidae Acilius fraternus (Harris) D, F TP, FM CC Dytiscidae Acilius mediatus (Say) D TP CC, C Dytiscidae Agabetes acuductus (Harris) D TP CC Dytiscidae Agabus disintegratus (Crotch) D TP CC Dytiscidae Agabus erythropterus (Say) D FM CC, DC Dytiscidae Agabus fl avovittata Larson & Wolfe D TP CC Dytiscidae Agabus gagates Aubé D, L S, D, CC, MB TP, L Dytiscidae Agabus obtusatus (Say) D, F FM, TP C, DC, PK, S Dytiscidae Agabus punctatus Melsheimer D PU CC Dytiscidae Bidessonotus inconspicuus (LeConte) D P CC Dytiscidae Celina hubbelli Young D P CC Dytiscidae Copelatus glyphicus (Say) D, F, P, TP, BM, BC, L FM, D CC, C, DC, MB, O, PK, S, T Dytiscidae Coptotomus longulus lenticus Hilsenhoff D TP CC Dytiscidae Desmopachria convexa (Aubé) D P CC Dytiscidae Heterosternuta wickhami (Zaitzev) F TP CC Dytiscidae Hydaticus aruspex Clark D, F TP CC Dytiscidae Hydaticus bimarginatus (Say) D P CC Dytiscidae Hydrocolus defl atus (Fall) D, F TP CC, S Dytiscidae Hydrocolus filiolus (Fall) D, F TP, S DC, S Dytiscidae Hydrocolus oblitus (Aubé) ? S W Dytiscidae Hydrocolus paugus (Fall) D TP CC Dytiscidae Hydrocolus persimilis (Crotch) D, F FM, P, CC, C PT Dytiscidae Hydroporus niger (Say) D, F, TP, S, CC, MB, L L, SL PK, T Dytiscidae Hydroporus rufilabris (Sharp) ? ? W Dytiscidae Hydrovatus pustulatus (Melsheimer) D P CC Dytiscidae Hygrotus nubilus (LeConte) D TP CC Dytiscidae Ilybius biguttatus (Germar) D, L P, R, CC, C, DC, L O, S Dytiscidae Laccophilus fasciatus rufus Melsheimer D, L, P, TP, BC, CC, C F D, FM Dytiscidae Laccophilus maculosus maculosus Say D, F FM, TP CC, C Dytiscidae Laccophilus proximus Say D, F TP BC, CC, C Dytiscidae Liodessus affinis (Say) D, F TP CC Dytiscidae Liodessus fuscatus (Crotch) D, F TP CC, O 2008 C.L. Staines and A.J. Mayor 513 Family Genus/species CM Habitat Distribution Dytiscidae Matus bicarinatus (Say) D TP CC Dytiscidae Matus ovatus Leech D TP CC Dytiscidae Neobidessus pullus (LeConte) ? ? W Dytiscidae Neoporus blanchardi (Sherman) D, F TP, S CC Dytiscidae Neoporus carolinus (Fall) D, F, M TP, S, BC, BM, M CC, O Dytiscidae Neoporus clypealis (Sharp) D, F TP CC, MB Dytiscidae Neoporus lobatus (Sharp) D SL CC Dytiscidae Neoporus mellitus (LeConte) ? ? W Dytiscidae Neoporus vittatipennis Gemminger D TP CC & Harold Dytiscidae Rhantus calidus (Fabricius) D, F, L TP, S, CC, C L Dytiscidae Thermonectes basillaris (Harris) D, F TP CC, C, T Dytiscidae Thermonectes ornaticollis (Aubé) D, F TP CC Dytiscidae Uvarus lacustris (Say) D, F FM, S, CC, C, O D, TP Dytiscidae Uvarus suburbanus (Fall) ? ? W Gyrinidae Dineutus americanus (Linnaeus) D SL CC Gyrinidae Dineutus carolinus LeConte D TP CC Gyrinidae Dineutus discolor Aubé D S CC, S Gyrinidae Dineutus horni Roberts D P CC Gyrinidae Dineutus nigrior Roberts D P CC Gyrinidae Gyrinus analis Say L L CC Gyrinidae Gyrinus gibber LeConte L L CC Haliplidae Haliplus annulatus Roberts H TP CC Haliplidae Haliplus fasciatus Aubé D, F TP CC Haliplidae Peltodytes muticus (LeConte) D, L P, L CC Haliplidae Peltodytes sexmaculatus Roberts D TP CC Haliplidae Peltodytes shermani Roberts D TP CC Helophoridae Helophorus linearis LeConte F FM C Helophoridae Helophorus lineatus Say D FM C Hydraenidae Hydraena marginicollis Kiesenwetter L L S Hydraenidae Ochthebius sp. L L S Hydrochidae Hydrochus inaequalis LeConte L L CH Hydrochidae Hydrochus rufipes Melsheimer L L CH Hydrophilidae Anacaena limbata (Fabricius) D, F FM, TP T Hydrophilidae Anacaena suturalis (LeConte) D, F D O, T Hydrophilidae Berosus aculeatus LeConte D TP CC Hydrophilidae Berosus exiguus (Say) L L CO Hydrophilidae Berosus fraternus LeConte D, F TP CC Hydrophilidae Berosus infuscatus LeConte D, F TP CC Hydrophilidae Berosus pantherinus LeConte D, F TP CC Hydrophilidae Berosus striatus (Say) D, F TP CC Hydrophilidae Cercyon assecla Smetana H DU BF, CC, G, NG, O, TC Hydrophilidae Cercyon atricapillus (Marsham) L L CC Hydrophilidae Cercyon haemorrhoidalis (Fabricius) H DU BF, CC, C, PK, TC Hydrophilidae Cercyon indistinctus Horn ? ? Sm Hydrophilidae Cercyon lateralis (Marsham) H DU BC, BF, CC, S, TC 514 Southeastern Naturalist Vol.7, No. 3 Family Genus/species CM Habitat Distribution Hydrophilidae Cercyon occallatus (Say) PT PT BM, CC, R, TC Hydrophilidae Cercyon praetextatus (Say) H, FIT, DU, AG, BC, BF, B B, FIT CC, C, CH, CO, G, LF, NG, PK, TC Hydrophilidae Cercyon pygmaeus (Illiger) H, FIT DU, BF, CC, C, FIT PK Hydrophilidae Cercyon quisquilius (Linnaeus) H DU BF Hydrophilidae Cercyon variegatus Sharp M M IG, T Hydrophilidae Cercyon versicolor Smetana H, L DU CC, O, S Hydrophilidae Cryptopleurum minutum (Fabricius) H, L DU, L AC, BF, C Hydrophilidae Cryptopleurum subtile Sharp L L CH Hydrophilidae Cymbiodyta blanchardi Horn F S CC, S, T Hydrophilidae Cymbiodyta chamberlaini Smetana F TP O Hydrophilidae Cymbiodyta rotunda (Say) D, F TP CC, C, DC Hydrophilidae Cymbiodyta semistriata (Zimmerman) D, F TP CC, T Hydrophilidae Cymbiodyta vindicata Fall D, F TP CC Hydrophilidae Dactylosternum abdominale (Fabricius) H DU T Hydrophilidae Enochrus cinctus (Say) D, F D, TP CC, C, R Hydrophilidae Enochrus consortus Green D, F SB, D BM Hydrophilidae Enochrus ochraceus (Melsheimer) D, F S, FM, CC, C, G TP Hydrophilidae Enochrus pygmaeus nebulosus (Say) D, F, L FM, TP, BM, CC, C, SB, L G, TC Hydrophilidae Helochares maculicollis Mulsant D SL T Hydrophilidae Hydrobius fuscipes (Linnaeus) D TP BC Hydrophilidae Hydrobius melaenum Germar D, L TP, L C Hydrophilidae Hydrochara soror Smetana D FM C Hydrophilidae Hydrophilus triangularis Say D TP CC Hydrophilidae Oosternum pubescens (LeConte) PT PT R Hydrophilidae Paracymus confusus Wooldridge D, F FM C Hydrophilidae Paracymus subcupreus (Say) D, F TP, S CC, C, CO, G, T, TC Hydrophilidae Phaenonotum exstriatum (Say) L L CC Hydrophilidae Sperchopsis tessellatus (Ziegler) D ST CC Hydrophilidae Sphaeridium bipustulatum Fabricius H DU BF, CC, C, O, TC Hydrophilidae Sphaeridium lunatum Fabricius H DU BF, C Hydrophilidae Sphaeridium scarabaeoides (Linnaeus) H DU C Hydrophilidae Tectosternum navicularis (Zimmerman) H DU CC, G Hydrophilidae Tropisternus blatchleyi d’Orchymont D, F TP, FM CC, C Hydrophilidae Tropisternus collaris (Fabricius) D SL, TP CC, C, NC, S Hydrophilidae Tropisternus lateralis nimbalis (Say) D TP CC, C, CO, FP, G, NC, SM, S Hydrophilidae Tropisternus natator d’Orchymont D TP, FM CC, C Noteridae Hydrocanthus iricolor Say D TP CC Noteridae Susphellius bicolor punctipennis (Sharp) D TP CC