Baumann, R.W. &. B.P. Stark. 2013. The genus Megaleuctra Neave (Plecoptera: Leuctridae) in North America. Illiesia, 9(06):65-93. Available online: http://www2.pms-lj.si/illiesia/papers/Illiesia09-06.pdf http://zoobank.org/urn:lsid:zoobank.org:pub:6FA6F27D-DBC8-4F39-8063-8BA3C5508155 THE GENUS MEGALEUCTRA NEAVE (PLECOPTERA: LEUCTRIDAE) IN NORTH AMERICA Richard W. Baumann1 and Bill P. Stark2 1 Department of Biology and Monte L. Bean Life Science Museum, Brigham Young University, Provo, UT, U.S.A. 84602 E-mail: [email protected] 2 Box 4045, Department of Biology, Mississippi College, Clinton, Mississippi, U.S.A. 39058 E-mail: [email protected] ABSTRACT The extant Nearctic Megaleuctra are reviewed and five species are recognized: M. complicata Claassen, M. flinti Baumann, M. kincaidi Frison, M. stigmata (Banks), and M. williamsae Hanson. Diagnostic illustrations and SEM images are provided for the male and female of all species. The females of M. complicata and M. flinti are described for the first time and M. sierra Fields is placed as a synonym of M. stigmata. Keywords: Plecoptera, stonefly, Leuctridae, Megaleuctra, North America INTRODUCTION Leuctridae has not always been secure. Illies (1967), The genus Megaleuctra Neave was established on primarily on the basis of internal male reproductive the basis of four female specimens collected in the morphology and female ovipositor structure, placed Kootenay Lake area of southeastern British the genus in the subfamily Notonemourinae (at that Columbia, Canada by Neave (1934). The genus is time considered part of the Capniidae). However, considered one of the rarest of stonefly genera this position was not accepted by Nelson and (Jewett 1959, Baumann et al. 1977, Scudder 1994, Hanson (1973), who continued to treat it as a Stagliano and Maxell 2010) and is usually associated primitive member of Leuctridae, and (Zwick 2000), with spring seeps and rheocrenes of the Appalachian who stated “Transformations of the paraproct base Mountains, Pacific Northwest, and the northern confirm that the genus Megaleuctra...belongs to Rocky Mountains. Two fossil species are known: M. Leuctridae; it is not a notonemourid…” and he jewetti Lewis, from Miocene deposits of the Latah includes it in this family in his paper on family larval Formation near Juliaetta, Idaho (Lewis 1969), and M. characters Zwick (2006). Terry (2003) suggests that neavei Ricker, described from a Prussian Baltic Amber the inclusion of Megaleuctra in Leuctridae renders the specimen from the Lower Oligocene (Ricker 1935; family paraphyletic and advocates recognition of a Illies 1967). Hynes (1988) postulated that Pleistocene new family, Megaleuctridae, to accommodate this ice ages caused the extinction of Megaleuctra in the enigmatic genus. Palearctic realm. However, recently Ham & Bae Adults of Megaleuctra can be distinguished from (2002) described the first Asian species from the all known Leuctridae by their large size, dark colored Republic of Korea, and Zwick (2010) and Zwick & stigma in the costal space of the forewing beyond the Baumann (2011) provide additional records. cord, six longitudinal veins in the hind wing, an The position of Megaleuctra as a genus within elaborate epiproct, which can appear in three Illiesia – http://www2.pms-lj.si/illiesia/ Volume 9 – Number 6 – Page 65 Baumann, R.W. &. B.P. Stark. 2013. The genus Megaleuctra Neave (Plecoptera: Leuctridae) in North America. Illiesia, 9(06):65-93. Available online: http://www2.pms-lj.si/illiesia/papers/Illiesia09-06.pdf positions on tergum 10: basal, midlength or Raleigh, NC completely extended, an elongate subanal probe OSUC Oregon State University Collection, which curves upward over the abdomen and fits in a Corvallis, OR dorsal groove in the epiproct, and a large ovipositor PMSL Slovenian Museum of Natural History, structure projecting beyond the abdominal apex in Ljubljana, Slovenia the female. RLBC Richard L. Bottorff Collection, Placerville, The Nearctic species form two distinct clades. The CA tips of the subanal probe of the Pacific Northwest RFSC Rebecca F. Surdick Collection, White Post, and Northern Rocky Mountain species, M. complicata VA Claassen, M. kincaidi Frison and M. stigmata (Banks) ROMC Royal Ontario Museum Collection, are similar, having an enlarged apically lobed Toronto, ON process which bears a subapical notch (Baumann et SAGC Scott A. Grubbs Collection, Western al. 1977; Claassen 1937; Fields 1977; Frison 1942; Kentucky University, Bowling Green, KY Jewett 1959). In contrast, the two Appalachian SEMC Snow Entomological Museum Collection, species, M. flinti Baumann and M. williamsae Hanson, Lawrence, KS have cylindrical, apically acute subanal probes UIIC University of Idaho Insect Collection, (Baumann 1973). Moscow, ID UMBS University of Montana Biological Station, MATERIALS AND METHODS Polson, MT The following personal and institutional UNTC University of North Texas Collection, collections were accessed as part of this study. Denton, TX USNM United States National Museum Collection, ABRC Austin Brady Richards Collection, Chico, Washington, D. C. CA USUC Utah State University Collection, Logan, BPSC Bill P. Stark Collection, Mississippi UT College, Clinton, MS UWVC University of West Virginia Collection, BYUC Brigham Young University Collection, Morgantown, WV Provo, UT VPIC Virginia Polytechnic Institute Collection, CASC California Academy of Science Collection, Blacksburg, VA San Francisco, CA ZCSC Zach Crete Stonefly Collection, Lolo, MT CHNC Charles H. Nelson Collection, Chattanooga, TN CNCI Canadian National Collection of Insects, Adult genitalia were studied with a WILD M8 or Ottawa, ON an Olympus SZH 10 stereomicroscope. Scanning CSUC Colorado State University Collection, Fort electron micrographs (SEM) were taken using a Collins, CO Philips XL30 ESEM FEG microscope at Brigham CUCC Clemson University Collection, Clemson, Young University, Provo, Utah, or an Amray 1810D SC microscope at Mississippi College, Clinton, CUIC Cornell University Collection, Ithaca, NY Mississippi. The SEM egg images were prepared at DBDC David B. Donald Collection, Regina, SK VPI&SU in Blacksburg, Virginia. The color FMNH Field Museum of Natural History, Chicago, photograph of the live male of M. stigmata was taken IL by Bob Newell using a Nikon D 300 camera with a INHS Illinois Natural History Survey, 105mm macro lens, that of the brachypterous male of Champaign, IL M. complicata by Brady Richards using a Sonyshot ISUI Iowa State University Collection, Ames, IA DSC-W80 camera and the macropterous female of M. JJLC Jonathan J. Lee Collection, Eureka, CA complicata by Greg Courtney with a Nikon D7000 MCZC Museum of Comparative Zoology DSLR camera with a Mikro-Nikkor 105mm lens and Collection, Cambridge, MA combination SB-800/R1 flash system. The line NCSU North Carolina State University Collection, drawings were constructed using a Wild M-7 Illiesia – http://www2.pms-lj.si/illiesia/ Volume 9 – Number 6 – Page 66 Baumann, R.W. &. B.P. Stark. 2013. The genus Megaleuctra Neave (Plecoptera: Leuctridae) in North America. Illiesia, 9(06):65-93. Available online: http://www2.pms-lj.si/illiesia/papers/Illiesia09-06.pdf Fig. 1. Megaleuctra stigmata, Talking Water Creek, Montana. Male, Live, habitus, dorsal, macropterous. (Photo courtesy of R.L. Newell). stereomicroscope with a camera lucida attachment. lobes (Figs. 21, 28); subanal probe expanded Previously published figures of Megaleuctra species above base and about mid length, tip thread-like from Baumann (1973) and Baumann et al. (1977) (Figs. 21, 22, 25, 29); known from Maryland, were used in some of the figure plates and Pennsylvania, West Virginia and Shenandoah permission was granted by the American National Park, Virginia ……………..…… M. flinti Entomological Society. 2’ Tergum 9 without median process or low lateral lobes (Figs. 74, 78); lateral aspect of subanal probe RESULTS AND DISCUSSION relatively uniform in diameter throughout, tip truncate (Fig. 75, 81); known from North and Key to the Adults of Extant Nearctic Megaleuctra South Carolina, Tennessee and the Mount Rogers area of southwestern Virginia ..….. M. williamsae Males 3 Tergum 9 bearing large pair of rounded dorsal processes near posterior margin, anterior margin 1 Tip of subanal probe acute or threadlike (Figs. 21- of process rounded, posterior margin angled 22, 25, 29, 75, 77, 81); known distribution abruptly downward, lateral profile forming a Appalachian Mountains region of eastern North broad arc (Figs. 55, 67), cerci short … M. stigmata America .………………………………….…….… 2 3’ Tergum 9 bearing smaller pair of processes near 1’ Tip of subanal probe enlarged and bearing a posterior margin, processes thinner and pointed subapical notch (Figs. 3, 10, 16, 36, 64, 68); known at apex, cerci long (Figs.3, 5, 36, 42) ..................… 4 distribution northern Rocky Mountains, Sierra 4 Processes on tergum 9 relatively symmetrical, Nevada and Cascades of western North broad basally, narrowed apically and bluntly America ……………………………..……..….... 3 pointed or conical at tip (Figs.6, 13), dorsal lobe of 2 Tergum 9 bearing a small, darkly sclerotized, subanal probe long, thin and pointed at tip (Fig. median, toothed process between low lateral 14), epiproct large, bearing large downward Illiesia – http://www2.pms-lj.si/illiesia/ Volume 9 – Number 6 – Page 67 Baumann, R.W. &. B.P. Stark. 2013. The genus Megaleuctra Neave (Plecoptera: Leuctridae) in North America. Illiesia, 9(06):65-93. Available online: http://www2.pms-lj.si/illiesia/papers/Illiesia09-06.pdf