Org Divers Evol (2015) 15:471–488 DOI 10.1007/s13127-015-0216-8 ORIGINAL ARTICLE Review of the Plangia graminea (Serville) complex and the description of new Plangia species from East Africa (Orthoptera: Phaneropteridae, Phaneropterinae) with data on habitat, bioacoustics, and chromosomes Claudia Hemp1 & Klaus-Gerhard Heller2 & Elżbieta Warchałowska-Śliwa3 & Beata Grzywacz3 & Andreas Hemp4 Received: 3 February 2015 /Accepted: 15 April 2015 /Published online: 24 May 2015 # Gesellschaft für Biologische Systematik 2015 Abstract The Plangia graminea complex is partly Introduction reviewed and two new species of Plangia are described, Plangia multimaculata n. sp. from savanna habitats and Plangia belongs to a group of canopy dwellers restricted to Plangia satiscaerulea n. sp. from the submontane zones Africa often occurring syntopically with other fully alate in northern Tanzania. Plangia compressa (Walker 1869) bushcrickets such as Eurycorypha Stål, the most species-rich is synonymized with P. graminea (Serville, 1838). Data group in African Phaneropterinae, or Arantia Stål, medium to on habitat, bioacoustics, and chromosomes are provided. large-sized species that are often widespread with almost 30 Both analyzed Plangia species showed the same chro- species described at present. Although numerous species have mosomal number. Compared to other investigated Afri- been described from these taxa, for most species little or noth- can Phaneropterinae, Plangia had a reduced chromo- ing is known about distribution, habitat, ecology, biology, and some number and thus shows a derived condition in their phylogenetic relationships. First studies on Eurycorpyha its genome. The sex chromosomes differed morphologi- (Hemp et al. 2013a) showed that groups of obviously closely cally in both investigated species of Plangia suggesting related species exist exhibiting morphological differences, different mechanisms leading to these differences. Niche spe- e.g., in the male genitalic system, with increasing geographi- cialization and the male calling song are discussed as drivers cal distance from each other suggesting that this for speciation in fully alate and thus mobile taxa. phaneropterine genus is under recent radiation while others such as the monotypic genus Euryastes Ragge are confined to small areas and are probably relicts of a former wider dis- Keywords New species . Bioacoustics . Chromosomes . tribution or remnants of taxa that once were more species-rich Speciation . Tanzania . Mt Kilimanjaro . Eastern Arc (Hemp et al. 2013b). Latter taxon may be trapped on the Mountains mountain range of the West Usambara Mountains in northern Tanzania probably due to its low mobility since it is a flight- less species and/or has a specialized habitat demand while taxa such as Eurycorypha or Plangia, being highly mobile * Claudia Hemp since they are fully alate, are under recent radiation also due [email protected] to their ability to adapt to a wide range of habitats. In case of taxa such as Arantia fasciata (Walker) or Plangia graminea 1 Department of Animal Ecology and Tropical Biology (Zoology III), reported to occur over large parts of tropical Africa also cov- University of Würzburg, Würzburg, Germany ering southern Africa, the question arose how fully alate 2 Magdeburg, Germany Phaneropterines cope with an obviously wide ecological niche 3 Institute of Systematics and Evolution of Animals, Polish Academy while others seem to be in recent radiation with numerous of Sciences, Kraków, Poland species present and species groups closely morphologically 4 Department of Plant Systematics, University of Bayreuth, related to each other. In this study, we focused on the Plangia Bayreuth, Germany graminea complex, an array of probably closely related 472 C. Hemp et al. species with only slight morphological differences. In Materials and methods entomological collections, BPlangia graminea^ speci- mens were collected from almost all over tropical Africa Identification The material was checked against the entomo- and southern Africa. A sound data set on their distribu- logical collections of the Natural History Museum, London, tion, the morphology, habitat, acoustics, and chromo- UK; the entomological collection of the Muséum National somes was obtained for two Plangia species occurring D'histoire Naturelle, Paris, France; the Museo Nacional de in eastern Africa and compared to P. graminea original- Ciencas Naturales, Madrid, Spain; and the Naturkunde Muse- ly described from the Cape Province of South Africa to um, Vienna, Austria. delimitate them and bring some light to large-scale spe- P. graminea specimens from the Cape Region of South ciation patterns of fully alate African Phaneropterinae Africa were studied and stored in the entomological collec- taxa. Since a sound climatical data set exists for the tions of Vienna and London since the type of this species is area of northern Tanzania, we were also able to deter- lost and compared to the East African specimens. mine the exact ecological niche in which these two species occur. Measurements Total body length, lateral aspect, refers to the Plangia is a rather nondescript genus, characterized mainly midline length of the insect from fastigium verticis to the tip of by negative features (Ragge 1980). From the similar genera the abdomen including the subgenital plate. In females, the Eurycorpyha, Oxygonatium,andMonteiroa, it is distin- ovipositor is not included in the measurement of the body guished by a narrow fastigium broad in the other genera. From length. Measurements of ovipositors were taken laterally from Plangiodes, it is distinguished by the frontogenal carinae and tip to base not regarding the curvature. elongate eyes (Ragge 1980). Recently, Massa (2014)erected an own genus Pseudoplangia with Plangia laminifera as the Depositories MfN: Museum für Naturkunde, Zentralinstitut sole species on grounds of a broader fastigium verticis, com- der Humboldt-Universität zu Berlin. BMNH: British Mu- pressed fore and mid tibiae, and the type of spines on the hind seum, Natural History, London, UK. ZMUC: Zoological tibiae which are different in Plangia. Museum, Copenhagen, Denmark. NMW: Naturkunde Mu- Plangia currently contains 11 species, distributed over the seum Wien. All other material remains in the collection of whole of tropical and southern Africa and Madagascar. Only C. Hemp. P. graminea is recorded from East African localities. Type species of the genus is P. graminea described from the Cape Field work and ecological analysis Plangia satiscaerulea n. Region of South Africa. sp. specimens were recorded at two locations on Mt. Kiliman- Plangia is characterized by a broad fastigium verticis jaro, and at one each in the North Pare and the East Usambara which is smooth or sulcate and often broader than the first Mountains. Plangia multimaculata n. sp. specimens were col- antennal segment; it is mostly slightly laterally com- lected at nine localities on Mt. Kilimanjaro and at one in the pressed and meets the equally broad fastigium of frons North Pare Mountains. Ecological data on Kilimanjaro have along a well-developed horizontal line with a deep medi- been collected since 1996 along 30 transects disposed across an sulcus. The antennae are long and very thin but do not wide ranges in elevation; these data include climatic parame- surpass the posterior tips of the tegmina. The eyes are ters, i.e., rainfall (mainly using funnel gauges, annual means, oval. The pronotum has a smooth, even, and broad disc; Hemp 2006a, b), temperature (using StowAway Tidbit data the anterior margin is straight or slightly in-curved while loggers with an accuracy of ±0.4 °C at 20 °C; annual means of the posterior margin is broadly rounded. The pronotal hourly measurements, Hemp 2006a), and vegetation parame- lobes are deeper than long with a broadly rounded ventral ters (over 1500 sampling plots=relevés, using the method of margin. All Plangia species are fully winged with tegmi- Braun-Blanquet, 1964). The altitudinal range of the transects na mostly elongated with broad posterior margin and extended from 760 m (Rau forest near Moshi) to 5.895 m acute tipped hind wings surpassing the tegmina. The ra- (Kibo peak). Climatic data for the East Usambaras were taken dial and subcostal veins are continuous for most of their from Hamilton (1989) and Iversen (1991). For estimates of length. There is little variation in the male genitalic sys- environmental humidity, mean annual temperatures tem. The tenth abdominal tergite is unmodified or little (MAT) and mean annual precipitation (MAP) were enlarged with normal shaped decussate rather stout cerci. scaled to obtain four humidity categories. In a first step, The subgenital plate also shows little variation, being MATandMAPwerescaledwith1°C/25mmtoestab- longish with small styli. The ovipositor of the females is lish a ratio between evaporation as determined by MAT well developed, up-curved, and with fine teeth. and water input as determined by MAP (Holdridge In splitting up Amblycoryphae/-ini, Cadena-Castañeda 1967; Lauer et al. 1996; Walter and Lieth 1967) (2015) placed Plangia and Monteiroa in the species group (Fig. 1). The 1:25 ratio roughly corresponds to the tran- Plangiae, based on unspecified morphological similarities. sition from semiarid to subhumid conditions in the East African Plangia species 473 Fig. 1 Habitat selection and altitudinal distribution of Plangia species in relation to climatic parameters. Line a:linear regression of mean annual temperature