Research Article |
Corresponding author: Wolfram Graf ( wolfram.graf@boku.ac.at ) Academic editor: Marco Gottardo
© 2014 Wolfram Graf, Martin Konar, Dávid Murányi, Kirill Orci, Simon Vitecek.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Graf W, Konar M, Murányi D, Orci K, Vitecek S (2014) A new species of Isoperla (Insecta, Plecoptera) from the Karawanken, with considerations on the Southern Limestone Alps as centers of endemism. ZooKeys 448: 27-36. https://doi.org/10.3897/zookeys.448.8509
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A new species of the genus Isoperla (Plecoptera, Perlodidae), belonging to the oxylepis species-group is described, and the male mating call is characterized. Its range falls within a small region of the Southern Limestone Alps which is well known to be one endemism-centre of aquatic insects.
Isoperla , new species, endemism, Austria, Slovenia, Southern Alps
The genus Isoperla consists of about 150 species (
Recently a series of specimens were collected from the Karawanken Alps in southern Austria and the nearby Kamnik Alps in northern Slovenia deviating from all hitherto known species. In this paper we provide morphological descriptions of males, females and the larva. Additionally we illustrate drumming signals of one male.
Adult specimens were collected using sweep nets, larvae were collected by handpicking from cobbles (mesolithal), the dominant substrate type. Collected specimens were stored in 70% ethanol. Morphological characteristics of male terminalia were examined in KOH-treated, cleared specimens. Comparative material from the authors’ collections enabled the identification of the new species.
Vibratory signal recordings were made using a small, dynamic speaker (SAL YD78) as a vibration transducer. The speaker was connected to the microphone input socket of a solid state, digital recorder (Zoom H4n). The examined specimen was placed on the diaphragm of the speaker. To prevent the specimen from escaping the speaker was covered by a sheet of hobby glass. During the recordings ambient air temperature was measured using a P 300W thermometer. Vibration recordings were analysed and oscillograms produced using the software Adobe Audition 1.5 (Adobe Systems Incorporated, San Jose, California, USA). Drumming signal terminology follows
Holotype: 1 male, Austria, Carinthia, Dolintschitschach brook south-east of Feistritz ob Bleiburg (46°32'6"N, 14°45'52"E), 600m a.s.l., 30.5.2014, leg. W. Graf; Paratypes: 3 males, 2 females, same place, date and collector. The holotype is deposited at the Linzer Landesmuseum, Linz, Austria, paratypes are stored in the first author's collection.
Other material. 1 male (drumming call examined), 1 female (HNHM: PLP4333), Slovenia, Upper Carniola, Kamnik municipality, Kamnik Alps, small forest brook S of Podvolovljek Pass (46°16.250'N 14°41.325'E), 980m a.s.l., 09.07.2013, leg. D. Murányi, I. Sivec.
Austria, Carinthia, Feistriz ob Bleiburg, Dolintschitschach brook.
The species is named in honour of the second author’s wife Claudia.
An Isoperla exhibiting the following combination of characters: (1) a small medial penial armature in the form of an equilateral triangle, lacking lateral penial armatures; (2) yellow head and pronotum with a small horseshoe-like brown marking connecting the occelli.
Medium-sized species, macropterous. Body length: holotype 10.5 mm, allotypes 11–12 mm; forewing length: holotype 12 mm, paratypes 12–14 mm. Primary colouration yellow, head and pronotum mostly yellow with dark brown markings; pilosity short. Primary colouration of the head yellow, with a dark horseshoe-like brown patch connecting the three ocelli (Fig.
Male abdomen (Fig.
Penis (Fig.
Penis of Isoperla claudiae sp. n. A ventral view of the extruded penis B medial penial armature, scale bar 50 µm C medial penial armature, scale bar 50 µm D scales of the medial penial armature, scale bar 20 µm E scales found caudally the medial penial armature, scale bar 20 µm F medial penial armature of I. orobica, scale bar 200 µm. Photographs A–E by W. Lechthaler, Vienna.
Female abdomen (Fig.
Larva (Fig.
The species was collected in a small spring-brook at 535 m a.s.l. in the Karawanken, and a small forest brook at 980 m a.s.l. in the Kamnik Alps (Southern Limestone Alps).
Since only one signal from a single male could be recorded we cannot give any information on the variation range of the signal parameters in this species. The aim of this preliminary description is only to report the basic features of the signal, but even that should be treated with some caution since we cannot be sure whether or not the recorded signal shows some deviant features.
As it is observable in (Fig.
Oscillograms showing the drumming call of an I. claudiae sp. n. male (ambient air temperature 24.2 °C). A oscillogram showing rhythm and amplitude variation patterns of a call B a faster oscillogram of two bi-beats from the second half of the call C variation of interval duration between bi-beats during the call presented in A. Inter-beat intervals were measured from the amplitude peak of one bi-beat to the amplitude peak of the next bi-beat (measured on the same call presented in A).
The new species can be attributed to the oxylepis species-group sensu
Isoperla claudiae sp. n. is most similar to I. orobica, a species restricted to the south-western Alps, but can be easily distinguished from the latter species as the scales of the medial penial armature are shorter in I. claudiae sp. n., a higher density of uncoloured scales on the penis in I. claudiae sp. n., as well as yellow, hardly visible rugosities of the pronotum in I. claudiae sp. n.
The male drumming call of I. claudiae sp. n. is clearly different from the drumming call of I. oxylepis, which is the only species of the I. oxylepis species-group, where published information regarding the vibratory signals is available (
The southern slopes of the Alps from the Ligurian Prealps in the southwest to the Pohorje Mountains in the east are densely covered by microendemic species. Concentrations of endemic species in the south and south-eastern Alps are well known among Trichoptera species (
The western alpine slopes (Biellese, Graian and Cottian Alps) are another area of alpine endemism where a high diversity within the genus Leuctra is found (
The authors acknowledge support from the BioFresh EU project–Biodiversity of Freshwater Ecosystems: Status, Trends, Pressures and Conservation Priorities (contract No. 226874). The bioacoustic research in this study was supported by the Hungarian Scientific Research Fund (OTKA K 81929). This study further was morally supported by the Austrian Science Fund (FWF) (project number P23687-B17).