Perlodes mortoni Klapalek 1906
Creators: name: Zwick, Peter
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Perlodidae
Perlodes
Perlodes mortoni

description: <i>Perlodes mortoni</i> Klapálek 1906, species propria <b>Material examined</b>. <i>Syntypes.</i> The complete original material sent by K. J. Morton seems to be in Klap {lek's collection in the Natural History Museum at Praha Kunratice. Most specimens are from "Uddington, 13.iv.1902, K.J. Morton " or very similar collecting dates, plus several specimens from Carluke, Scotland, K.J. Morton (several dates; one &amp;female; with " <i>Dictyopteryx microcephala</i> Pict. " in Morton's hand). There are also 1&amp;male;, 1&amp;female; from "3.v.80 Gotha Dr. Müller " mentioned in Klap{lek (1906). Several Scottish specimens are labelled "Cotype", only 2&amp;female; from "Uddington, 13.iv.1902, K. J. Morton " are labelled "Type". For lack of time, biometry was not performed and only one of the latter two females was studied for eggs. Its abdomen is detached and on a card pinned with the fore body, several eggs are in Euparal on a plastic slide pinned with the specimen, plus a few eggs on a glass slide presently in my collection. <b>Additional material.</b> Scotland: R. Tweed at Innerleithen, 1.v.2010, D. Pryce, under stones, 25&amp;male;, 15&amp;female;; Perthshire, Dunkeld, R. Tay, late April 1990, Andreas Zwick, 1&amp;male;, 1&amp;female;; Wales: R. Dee at Pen-y-Lan, Clwyd / Shropshire border, iii.2004, Malaise trap, D. Pryce, 4&amp;male;, 3&amp;female;; <b>Brachypterism.</b> Very similar to <i>P. dispar</i>, male wings between 1.4 and 1.8 times as long as head width, peaking at a RWL of 1.6 (Fig. 4). <b>Egg structure</b> (Fig. 5). Sclerites on the anchor disc margin differ extremely between specimens taken together, ranging from relatively large plates longer than wide and in one case also with a clockwise twist (<i>mo-3</i>) to irregularly shaped sclerites placed at distances from each other along the disc periphery, to a single row of short, transverse sclerites (<i>mo-5</i>), and ultimately, numerous small sclerites which on their medial edge may not be clearly separate from very small sclerotized patches (<i>mo-6, mo-7</i>). The spectrum of observed character expressions was similar between British rivers, there were more specimens with relatively small than with large sclerites. There are no clear differences from the presumed aberrant population of <i>P. microcephalus</i> from Medingen, N. Germany. Unlike in <i>P. dispar</i>, brown pigmentation and sclerotization of structures along the anchor disc margin were always expressed. <b>Notes.</b> Illies (1955) formally synonymized <i>P. mortoni</i> with <i>P. microcephalus.</i> Evidence for this decision was not mentioned. Historical specimen labels reveal that K. J. Morton had felt the same. Other students also agreed that the single British - Irish <i>Perlodes</i> is indeed <i>P. microcephalus</i> (for example, Hynes 1967, 1977, Costello 1988a, Elliott 1992, Ashe, O'Connor &amp; Murray 1998). Short-wingedness of the Irish Plecoptera received special attention but no male <i>P. mortoni</i> was available (Costello 1988b). I abstain from the originally intended lectotype designation because: 1, not all of the evident syntypes could be adequately studied; 2, fresh material shows that egg anchor sclerites vary too much for any single specimen to represent a reference specimen characteristic of the species.
description: Published as part of <i>Zwick, Peter, 2011, Polymorphism And Taxonomic Problems In The Perlodes Microcephalus Group (Plecoptera: Perlodidae); Perlodes Mortoni Removed From Synonymy, pp. 291-296 in Illiesia 7 (26)</i> on pages 293-295, DOI: 10.5281/zenodo.4758218
description: {"references": ["Illies, J. 1955. Steinfliegen oder Plecoptera. In: Dahl, F. (ed.) 1955. Die Tierwelt Deutschlands und der angrenzenden Meeresteile 43: I-IV; 1 - 150.", "Hynes, H. B. N. 1967. A key tot he adults and nymphs oft he British stoneflies (Plecoptera) with notes on their ecology and distribution. Scientific Publications - Freshwater Biological Association, 2 nd extended ed., 17: 1 - 91", "Hynes, H. B. N. 1977. A key to the adults and nymphs of the British stoneflies (Plecoptera) with notes on their ecology and distribution. Scientific Publications - Freshwater Biological Association, 3 rd ed., 17: 92 pp.", "Costello, M. J. 1988 a. A review of the distribution of stoneflies (Insecta, Plecoptera) in Ireland. Proceedings of the Royal Irish Academy, 88 B (1): 1 - 22.", "Elliott, J. M. 1992. The effect of temperature on egg hatching for three populations of Perlodes microcephala (PICTET) and three populations of Diura bicaudata (LINNAEUS) (Plecoptera: Perlodidae). Entomologists' Gazette, 43: 115 - 123.", "Ashe, P., J. P. O'Connor, &amp; D. A. Murray. 1998. A Checklist of Irish Aquatic Insects. Occasional Publications of the Irish biogeographical Society, 3, 80 pp.", "Costello, M. J. 1988 b. Preliminary observations on wing-length polymorphism in stoneflies (Plecoptera: Insecta) in Ireland. Irish Naturalists' Journal, 22 (11): 474 - 478."]}