Leuctra hippopus Kempny, 1899 (Plecoptera: Leuctridae): studies on a species problem, with notes on related species. Torfinn 0rmen CAND. SCIENT. THESIS IN SYSTEMATIC ZOOLOGY UNIVERSITY OF OSLO, ZOOLOGICAL MUSEUM 1991 0rmen, Torfinn "Le~ictra hippopus Kempny, 1899 (Plecoptera: Leuctridae): studies on a species problem, with notes on related species." Cand. scient. thesis, systematic zoology. University of Oslo, Zoological Museum, 1991. Keywords: stonef!ies, speciation, taxonomy, eco-species, drumming, copulation, morphometry, iso-electric focusing, reproductive isolation, zoogeography, immi­ gration routes. Lay-out and type-setting (with TEX) by the author. Where not stated otherwise the illustrations are originals. © Copyright Torfinn 0rmen 1991. Verbatim copies of this document may be freely distributed on a non-profit basis, provided that this notice and the copyright notice is included. To Titti & M oniqtie for making the lab a pleasant place to be I would like to express my gratitude to all those at the Zoological Museum in Oslo who contributed to this work, directly-or indirectly by creating the milieu. For the former a list of acknowledgements is given on page 68, but I want especially to mention my supervisors, doctors and head curators Albert Lillehammer and Tor Andreas Bakke at the Zoological Museum for help and guidence. In addition I would like to thank my friends and fellow students for not booting me out of their company because of excessive tall' about rather uninteresting animals and problems. Some comments must be made on the form of this document: This work is devided into three analytical parts with greatly different methods and I therefore found it impractical to use the "usual" set-up with chapters on "Introduc­ tion", "Material and methods", "Results", "Discussion", and "Conclusion". Instead, after the normal introductory chapter, the localities are given a chapter on their own and, so are the methods shared between the analytical parts, while the three analytical parts are given one chapter each, each with sections on introduction, material, meth­ ods, results, and discussion. The final discussion and conclusion is given in a separate chapter. Torfinn 0rmen T¢yen, 5/6-91 List of contents Part page Resyme ..................................................................... 1 Summary ................................................................... 2 Chapter 1: Introduction .................................................. 3 1.1 The animals in question ................................................. 3 1.1.1 Plecoptera - stonefl.ies ............................................. 3 1.1.2 Leuctra - needlefl.ies ............................................... 3 1.1.3 Leuctra hippopus Kempny, 1899 - the "horse-foot fl.y" .............. 4 1.2 The problem ........................................................... .4 1.3 How to solve the problem ............................................... 5 1.3.l Definition of the applied species concept ............................. 5 1.3.2 Species confirmation vs. species description .......................... 6 1.3.3 The question of reproductive isolation ............................... 7 1.3.4 Application of the concept .......................................... 8 Chapter 2: Localities and populations ................................... 9 2.1 Introduction ............................................................ 9 2.2 N¢klevann ............................................... '.............. 10 2.3 Suldalslagen ........................................................... 10 2.4 Isterfoss ............................................................... 11 2.4.1 History and geomorphology ...................... .' ................. 11 2.4.2 Animal life ........................................................ 12 2.4.3 Wind exposure ......... ·........................................... 13 2.4.4 The threat of the flood ............................................ 13 2.4.5 Gene-fl.ow ................................. : ....................... 14 2.5 Additional localities ................................................... 15 2.5.1 "Non-hippopus" localities .......................................... 15 2.5.2 "hippopiis" localities ............................................... 15 Chapter 3: Shared materials and methods ............................. 16 3.1 Introduction ........................................................... 16 3.2 Sampling .............................................................. 16 3.3 Keeping the animals alive .............................................. 16 3.4 Determination of sex in live adults ..................................... 17 3.5 Determination of specific identity ...................................... 17 3.6 A mating experiment .................................................. 17 3. 7 Practical problems ..................................................... 17 Chapter 4: Pre-mating: ethological isolation? ......................... 18 4.1 Introduction ........................................................... 18 4.2 Evaluation of possible mechanisms ..................................... 18 /4.2.1 Long range ........................................................ 18 4.2.2 Short range ........................................................ 19 · 4.3 Stonefly drumming .................................................... 19 4.4 Equipment, material and methods ..................................... 20 4.4.1 Equipment ........................................................ 20 4.4.2 Material ........................................................... 21 4.4.3 Method ............................................................ 21 4.5 Results ................................................................ 22 4.5.l General. ........................................................... 22 4.5.2 Isterfoss ........................................................... 23 4.5.3 Suldalslagen ....................................................... 24 4.5.4 N¢klevann ......................................................... 24 4.5.5 Sreterbekken ....................................................... 25 4.5.6 Lukedammen ............................................... , ...... 25 4.6 Observation from the mating experiment ............................... 25 4.7 Conclusion ............................................................ 26 4.7.l Long range ........................................................ 26 4.7.2 Short range ........................................................ 26 Chapter 5: Mating: mechanical isolation? ............................. 27 5.1 Introduction ........................................................... 27 5.2 Descriptive: Copulation in Leuctra . .................................... 27 5.2.1 Introduction ....................................................... 27 5.2.2 Material and method .............................................. 28 5.2.3 Definitions ......................................................... 29 5.2.4 Leuctra in general ................................................. 32 5.2.5 Leuctra hippopus . .................................................. 33 5.3 Analytical: Method .................................................... 35 5.4 Analytical: Results .................................................... 36 5.4.1 General. ........................................................... 36 5.4.2 On a Norwegian scale .............................................. 36 5.4.3 On a larger geographic scale ....................................... 38 5.5 Related described species .............................................. 42 5.5.l Leuctra hippopoides Kacanski & Zwick, 1970 ....................... 42 5.5.2 Leuctra elisabethae Ravizza, 1985 .................................. 42 5.5.3 Lrnctra collaris Martynov, 1928 & L. pseudohippopus Rauser, 1965 . 43 5.5.4 Leuctra vaillanti Aubert, 1956 ..................................... 43 5.5.5 Leuctra fraterna Morton, 1930 & L. andafosiaca Aubert, 1962 ...... 43 5.5.6 Leuctra delamellata & L. mimtta Zhil'tsova, 1960 & L. anatolica Kazanci, 1986 ....................................... 44 5.5.7 Leuctra aculeata Zwick, 1982 ....................................... 44 5.6 Observation from the mating experiment .............................. .45 5.6.1 Regarding body-weight ............................................ 45 5.6.2 Regarding body-length ............................................ .45 5.6.3 Regarding genitalia ................................................ 45 Chapter 6: Post-mating: biochemical isolation? ....................... 47 6.1 Introduction ........................................................... 47 6.2 MateriaJ ............................................................... 48 6.3 Method ............................................................... .48 6.3.1 Preservation of material ........................................... 48 6.3.2 !so-electric focusing, theory ........................................ 48 6.3.3 Preparation of gel solution ......................................... 48 6.3.4 Gel casting ........................................................ 49 6.3.5 Preparation of samples ............. : .............................. .49 6.3.6 Application ........................................................ 49 6.3.7 Running ........................................................... 50 6.3.S Fixing ............................................................. 50 6.3.9 Staining ........................................................... 51 6.3.10