Research Article |
Corresponding author: Bruno Massa ( bruno.massa@unipa.it ) Academic editor: Susanne Randolf
© 2018 Bruno Massa, Klaus-Gerhard Heller, Elżbieta Warchałowska-Śliwa, Nicolas Moulin.
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:
Massa B, Heller K-G, Warchałowska-Śliwa E, Moulin N (2018) The tropical African genus Morgenia (Orthoptera, Tettigoniidae, Phaneropterinae) with emphasis on the spur at the mid tibia. Deutsche Entomologische Zeitschrift 65(2): 161-175. https://doi.org/10.3897/dez.65.26693
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The authors revised the genus Morgenia Karsch, 1890 which now consists of eight species, of which three are here newly described (Morgenia plurimaculata Massa & Moulin, sp. n., M. angustipinnata Massa, sp. n., and M. lehmannorum Heller & Massa, sp. n.). Six of the eight species occur in the Tri National Sangha (TNS) comprising Dzanga-Sangha Special Reserve and Dzanga Ndoki National Park (Central African Republic), whose high biodiversity has been recently highlighted. In particular the genus is characterised by the presence of a more or less long spur at the inner mid tibia, different in each species; in M. modulata, it moved lower down into a new position at about ¼ of tibia, which has a hollow underneath where the rest of the spur remains hidden. This is a unique known case in Phaneropterinae. Morphological characters distinguishing males of different species are presented. Bioacoustics of the new species M. lehmannorum are described. The patterns of the chromosome evolution in M. lehmannorum differ from other investigated African Phaneropterinae in terms of chromosome number and morphology, reduced ancestral chromosome number (2n = 25) implying a more derived condition.
Taxonomy, new species, bioacoustics, cytogenetics
The genus Morgenia was described by
Presently eight species of Morgenia are known in tropical Africa; six of them occur in the Tri National Sangha (TNS) comprising Dzanga-Sangha Special Reserve and Dzanga Ndoki National Park (Central African Republic). We should point out the remarkable importance of this area from the conservation and the biodiversity point of view. Recently different papers on insects of this area have been published, showing the high diversity of co-occurring species (
Some specimens were collected in the field during expeditions in tropical Africa. Most Orthoptera were collected at night with the aid of UV lamps, one installed above ground, the other placed under a canopy. Specimens were dried by smoke and preserved individually in paper bags each day. These bags were later sent to the Department of Agricultural, Food and Forest Sciences, Palermo University, Italy and were later mounted.
Central African Republic site: Dzanga-Ndoki National Park is part of the Sangha Trinational, a UNESCO World Heritage Site which covers an area of 4,520,000 ha and includes three national Parks: Loboke (Cameroon), Nouabale-Ndoki (Congo) and Dzanga-Ndoki (Central African Republic). Dzanga-Ndoki National Park is located in the Congo River basin, within an extensive tropical forest, approximately six days walk from the nearest inhabited village and constitutes a very rich sanctuary of biodiversity which is still poorly known. The park is bordered to the West by the Sangha River, which also borders with Cameroon and contains more than ten natural lakes of different size (from ca. 1 km by 400 m to 100 m by 150 m). Dzanga-Ndoki National Park is located in the extreme southwest of the Central African Republic, in a triangular-shaped part of the country. Established in 1990, it is divided into two non-continuous sectors: the northern Dzanga Park (49,500 ha) and the southern Ndoki Park (72,500 ha). The two are joined by the Dzanga-Sangha Rainforest Reserve (335,900 ha), where controlled hunting and other exploitation is allowed. The whole park is on alluvial sands; along streams, forest clearings can be found with marshy depressions. The Dzanga Bai (= the village of elephants) is a sandy salt lick that measures 250 m by 500 m. It is traversed through the middle by the Dzanga stream. There are three types of forest within Dzanga-Ndoki National Park: mainly dry-land, a semi-evergreen forest that contains swamp-forest areas along the rivers and a closed-canopy, mono-dominant Gilbertiodendron dewevrei forest. The dry-land forest is an open, mixed canopy that is dominated by Sterculiaceae and Ulmaceae; often associated with it is a dense understorey of Marantaceae and Zingiberaceae (
Gabonese site: Research Station on Gorilla and Chimpanzee (SEGC-CIRMF, Station d’Etudes des Gorilles et Chimpanzés, gérée par le Centre International de Recherches Médicales de Franceville) is situated in the northern part of Lopé National Park, about 10 km south from Lopé village and the Dr Alphonse Mackanga Missandzou Training Center (CEDAMM, Wildlife Conservation Society; coordinates: 0°12’09.62”S, 11°36’05.19”E; altitude 265m). Vegetation comprises a mosaic of forest and shrub savannah. Shrub savannah is dominated by Poaceae and Cyperaceae like Anadelphia arrecta, Andropogon pseudapricus, Schizachyrium platyphyllum, Hyparrhenia diplandra or Ctenium newtonii and by a shrub layer with Nauclea latifolia and Crossopteryx febrifuga (
Ivory Coast site: Research Station in the Taï Forest National Park. It is one of the last primary forests in western Africa, UNESCO Heritage, is bordered by the Sassandra river to the east, by Liberia to the west, by Peko and Saon Mts to the north and by Nieno Koué Mt. to the south. The park covers 3,300 km2. Some entomological expeditions to Taï Forest were carried out in 2015–2017, managed by Philippe Moretto.
A series of specimens were examined from collections housed in the museums or collections cited below. Abbreviations used in this paper:
BMPC Bruno Massa Collection, University of Palermo;
Some specimens were photographed with a Nikon Coolpix 4500 digital camera, mounted on a Wild M5 Stereomicroscope or Leica MZ75 and photographs were integrated using the freeware CombineZP (
The shape of the stridulatory file under the male’s left forewing and the number and arrangement of the teeth are useful characters that identify whether a species is bioacoustically separated from another one (
Bioacoustical methods and terminology. The male calling songs of one specimen of a new species from Uganda (Morgenia lehmannorum Heller & Massa sp. n.) were recorded in the laboratory using a digital bat detector (Pettersson D1000X; sampling rate 100 or 192 kHz). The sounds were analysed using the programmes Amadeus II (Martin Hairer; http://www.hairersoft.com) and Audacity (Audacity 2.1.0; http://audacity.sourceforge.net). For the frequency measurements, 8–12 ms sections were evaluated, using fast fourier transformation (FFT) analysis, hanning window, 512 points per frame, one or mean of several overlapping frames. Oscillograms of the songs were prepared using Turbolab (Bressner Technology, Germany). All recordings were made at temperatures between 20 and 21 °C. The singing insect was caged in a gauze cage with a microphone fixed at a distance of ca. 80 cm. Results are given as mean±standard deviation.
The following definitions describe the terminology used during this work:
Syllable: sound produced during one cycle of movements (opening and closing of the tegmina); syllable duration: time period measured from the first impulse to the last; impulse: a simple, undivided, transient train of sound waves (here: the damped sound impulse arising from the contact of one tooth of the stridulatory file with the scraper); pulse: undivided train of sound waves increasing in amplitude at the beginning and containing several similarly sized wave maxima and minima (cricket-like song structure).
One male (CH7840) of Morgenia lehmannorum Heller & Massa sp. n. was used for cytotaxonomic analyses. The testes were incubated in a hypotonic solution (0.9% sodium citrate) and fixed in ethanol : acetic acid (3:1). The fixed material was stored in 70% ethanol at 2 °C until use. Subsequently, the testes were macerated in 45% acetic acid and squashed. The cover slips were removed using the dry ice procedure and the preparations were air dried. The C-banding examination was carried out according to
DNA barcoding, the analysis of a standardised segment of the mitochondrial cytochrome c oxidase subunit I (COI) gene, was performed on three specimens from Gabon in the project context: “ORGAA – Orthoptera of Gabon – Project 1 [ECOTROP 2014]” on Barcode of Life Data System (BOLD, Biodiversity Institute of Ontario, Canada; boldsystems.org). Tissues were sent to the Canadian Institute for DNA extraction, polymerase chain reaction (PCR) and sequencing. PCR was performed using the PCR primers C_LepFolF/C_LeFolR (
Characters of the genus Morgenia Karsch, 1890 (Tribe Poreuomenini Brunner von Wattenwyl, 1878)
Fastigium of vertex quite acuminate, not contiguous with fastigium of frons. Pronotum narrow, superiorly flat, anterior margin concave, posterior margin rounded, humeral sinus rounded, lateral lobes as wide as high, inferior margin rounded. Tegmina with rounded margins, wide mirror in the right tegmen. Wings exceeding tegmina a little. Legs slender, fore coxae armed, femurs inferiorly armed, fore tibiae with inner tympanum conchate, outer open; fore and mid tibiae superiorly sulcate, with spinules. Mid tibiae of males provided with an inner ventral moving spur before the apex, not exceeding the first tarsal article, longer or shorter depending on the species (with the exception of M. modulata, where it has a different shape); in the females, this spur is absent. Supra-anal plate nearly concave, cerci stout, curved and provided with an apical spine. Subgenital plate deeply concave, wide, without styli (
The species of the genus Morgenia have one of two types of cerci: a) club-shaped, with concave internal and rounded external part, armed at the apex; b) stout and incurved, with concave internal and rounded external part, armed at the apex. In addition, four lesser known facts have been highlighted: c) tegmina may be more or less wide and differences in the ratio length/width allow the separation of some species; d) costal area of tegmina may have a pattern with regularly spaced crossveins or a net of small cells; e) the inner ventral spur of the mid tibia has three different patterns; f) the stridulatory file is very characteristic for each species. Here the species are arranged by the type of cerci, according to their affinities.
The two final tables and relative photographs summarise the main characters of the species.
Karsch, 1890a. Entom. Nachricht. 16: 263.
Type locality: Kribi (Cameroon) (
Cameroon, Kribi (holotype ♂) (
M. hamuligera was the first species described in the genus Morgenia, from Kribi (Cameroon) and later reported from Barombi Station (Cameroon) (
The short description by
Measurements of tegmina length and width and ratio of tegmina length/width of the eight species currently known in the genus Morgenia.
Species | Tegmina length | Tegmina width | Tegmina length/width |
---|---|---|---|
Morgenia hamuligera (n = 10)1 | 33.2±1.4 (30.3–34.9) | 8.3±0.4 (8.0–9.2) | 4.0±0.3 (3.5–4.2) |
Morgenia rubricornis (n = 10) | 29.4±1.1 (27.5–30.2) | 7.5±0.5 (7.0–8.5) | 3.9±0.2 (3.3–4.2) |
Morgenia spathulifera (n = 5) | 29.6±1.4 (27.9–31.4) | 4.5±0.1 (4.3–4.6) | 6.6±0.2 (6.4–6.8) |
Morgenia plurimaculata sp. n. (n = 10) | 34.1±0.9 (33.0–35.7) | 8.0±0.2 (7.8–8.5) | 4.2±0.1 (4.1–4.4) |
Morgenia lehmannorum sp. n. (n = 1) | 32.5 | 5.4 | 6.0 |
Morgenia angustipinnata sp. n. (n = 4) | 32.0±1.7 (30.5–33.9) | 5.0±0.4 (4.7–5.4) | 6.4±0.1 (6.3–6.5) |
Morgenia melica (n = 10) | 34.3±2.2 (29.0–36.9) | 7.6±0.3 (7.0–8.0) | 4.5±0.2 (4.1–4.8) |
Morgenia modulata (n = 10) | 30.4±0.9 (29.1–31.4) | 6.7±0.5 (6.0–7.6) | 4.5±0.2 (4.1–4.9) |
Sjöstedt, 1913. Ark. Zool. 8 (6): 4.
Type locality: Mukimbungu (Democratic Republic of the Congo) (
Central African Republic, Dzanga-Ndoki National Park, (light) 22.X.2008 (light), P. Annoyer (1♂); same data 24.II.2012 (light), P. Annoyer (1♂); 31.I.–29.II.2012 (11♂, 1♀) (light), Sangha2012 team; Gabon, Lope National Park Res. Station, Ogooue-Ivindo 28–31.III.2014 (light), (2♂, BOLD LopeORT14-617 and -673) (light), ecotrop 2014 team; Ivory Coast, Korhogo, Kogo 21.VII.2014 (1♂) (light), P. Moretto; Man Mt. Tonkoui (1200 m) 28.VI-1.VII.2014, 18–20.VI.2015 (2♂) (light), P. Moretto; Touba, Biémasso 10–11.VII.2013 (1♂) (light), P. Moretto; Täi National Park, Res. Station 20.III.2017 (light), B. Massa (1♂) (BMPC).
M. rubricornis was known only from the type locality; however, it has also been found in Central African Republic, Gabon and Ivory Coast (see material examined). Thus, its distribution probably covers central and western tropical Africa.
According to
Griffini, 1908. Mem. Soc. entom. Belgique, Bruxelles 15: 209.
Type locality: Bussanga (Democratic Republic of Congo) (
Democratic Republic of the Congo, Bussanga 14.XI.1905 (1♂ syntype); Ngowa 9.I.1939 (1♂), J. Mertens; Cameroon, Mukonje Farm, R. Rohde (1♀ syntype); Mt Koupé 31.I-8.II.1983 (1♂), J. van Stalle (
M. spathulifera is presently known from Cameroon, Democratic Republic of the Congo and Ivory Coast (
M. spathulifera may be easily separated from other known species by the ratio length/width of the tegmina (6.4–6.8). It is also characterised by the presence of small grey dots on the tegmina and costal area of the tegmina with a net of small cells (Figs
Central African Republic, Dzanga-Ndoki National Park, Lakes Region (02°28’40.5”N, 16°13’02.6”E) 31.I.–29.II.2012 (light), Sangha2012 team (1♂ holotype, 19♂ and 3♀ paratypes); Mboki (5°18’31”N, 25°57’16”E) 24.I.2012 (2♂ paratypes) (♂ holotype and 1♀ paratype in the
At the present time, known only from the type locality, Dzanga-Ndoki National Park (Central African Republic).
Head and pronotum yellow-green with scattered brown spots, antennae yellowish, abdomen yellow-brown, cerci yellow-blackish, tegmina with a black spot at their base, green with black stridulatory area and small brown spots between cells; in some specimens, the black area is lacking. One black spot between tympana of fore tibiae is found only in males.
Males. Head and antennae. Fastigium of vertex narrow, sulcate above, not contiguous with fastigium of frons. Eyes rounded, well projecting. Antennae longer than body. Legs. Fore coxae armed with a fine spine. Fore tibiae furrowed on upper margin, distinctly widening above tympanum, conchate on inner, open on outer side. Fore femora armed on inner ventral side with 6 small spines, fore tibiae with 4 spines + 1 spur on inner side and 3 spines + 1 spur on outer ventral side, mid femora unarmed, mid tibiae with 4–5 outer and 2–3 inner ventral spines. The inner ventral spur of mid tibiae is short and does not exceed the first tarsal article; its length is about 5.0–5.5% the length of tibia. On the outer ventral margin of mid tibiae, three closely set short spines are present (Fig.
Females. Same characters of the males except for the following. The colour of fore legs is yellow without the black spot between tympana. Also, tegmina lack the black area but have small brown spots between cells. Interestingly, the costal area of tegmina differes from that of males by the regularly spaced crossveins. Ovipositor gently up-curved, 6.8–7.0 mm long, tips finely toothed. Cerci long and pointed, subgenital plate narrow and pointed.
M. plurimaculata sp. n. is characterised by club-shaped cerci, a short spur on the mid tibia, the stridulatory area with a small dark spot, many small dark spots scattered on tegmina in most specimens, pattern of the costal area of tegmina with a net of small cells and a stridulatory file that is 2.8 mm long, arched and composed of ca. 90 widely spaced teeth. The stridulatory area is composed of the stridulatory file and of a raised parallel posterior bulge. Differences to other species of the genus are summarised in Table
From Latin plus pluris = many and maculata = provided with spots.
Stridulatory area of left tegmen and mirror of right tegmen of the male of Morgenia hamuligera (9), M. rubricornis (10), M. spathulifera (11), M. lehmannorum sp. n. (12); habitus of M. hamuligera after
Uganda, Semliki Forest National Park (00°49’30”N, 30°03’40”E) 1–31.VIII.2014, A. and G. Lehmann (♂ holotype) (
Presently known only from the type locality, Semliki Forest (Uganda).
Green, with the exception of tympana of fore legs that are brown and one black spot between tympana. Stridulatory area brownish. Black spots at the base of tegmina.
Males. Head and antennae. Fastigium of vertex narrow, sulcate above, not contiguous with fastigium of frons. Eyes rounded, well projecting. Legs. Fore coxae armed with a fine spine. Fore tibiae furrowed on upper margin, distinctly widening above tympanum, conchate on inner, open on outer side. Fore femora armed on inner ventral side with 4 small spines, fore tibiae with 2 spines + 1 spur on inner ventral side and 1 spine + 1 spur on outer ventral side, mid femora unarmed, mid tibiae with 2 outer and 2 inner ventral spines, inner ventral spur of mid tibiae long, up-curved, exceeding ¾ of the first tarsal article; its length is about 10% the length of tibia. On the outer ventral margin of mid tibiae, three close short spines are present (Fig.
M. lehmannorum sp. n. is characterised by narrow tegmina (Table
Main characters that allow the separation of males of the eight species of the genus Morgenia.
Spot on stridulatory area | Costal area of tegmina | Stridulatory file | Cerci | Subgenital plate (ventral) | Subgenital plate (lateral) | Spur of mid tibia | |
---|---|---|---|---|---|---|---|
Morgenia hamuligera | Blackish, rectangular (Figs |
Spaced crossveins (Fig. |
3.5 mm long (80 dense + 70 widely spaced teeth) (Fig. |
Club-shaped (Fig. |
Widely concave (Fig. |
Rather straight (Fig. |
Long and pointed (Fig. |
Morgenia rubricornis | Blackish, triangular (Figs |
Spaced crossveins (Fig. |
2.2 mm long (60 dense + 50 widely spaced teeth) (Fig. |
Club-shaped (Fig. |
Widely concave (Fig. |
Tips up-curved (Fig. |
Long and more or less up-curved (Fig. |
Morgenia spathulifera | Very few small spots on tegmina (Fig. |
Net of small cells (Fig. |
1.2 mm long (60 densely spaced teeth) (Fig. |
Club-shaped (Fig. |
Concave, interior margins undulate (Fig. |
Rather straight (Fig. |
Very short and up-curved (Fig. |
Morgenia plurimaculata sp. n. | Few scattered spots on tegmina in most specimens (Figs |
Net of small cells (Fig. |
2.8 mm long (90 widely spaced teeth) (Fig. |
Club-shaped (Fig. |
Widely concave (Fig. |
Tips down-curved (Fig. |
Short and pointed (Fig. |
Morgenia lehmannorum sp. n. | Very few (Figs |
Net of small cells (Fig. |
1.8 mm long (ca. 100 teeth, distal more widely spaced than proximal) (Fig. |
Club-shaped (Fig. |
Small apical concavity (Fig. |
Rather straight (Fig. |
Long and up-curved (Fig. |
Morgenia angustipinnata sp. n. | Very few, brownish (Fig. |
Net of small cells (Fig. |
1.7 mm long (70 widely spaced teeth) (Fig. |
Club-shaped (Fig. |
Long and narrow, small concavity, interior margins undulate (Fig. |
Rather straight (Fig. |
Very short and up-curved (Fig. |
Morgenia melica | Blackish, more or less square (Fig. |
Spaced crossveins (Fig. |
2.3 mm long (70 widely spaced teeth) (Fig. |
Slender, apically flattened (Fig. |
Widely concave, tips divergent (Fig. |
Tips up-curved (Fig. |
Long and pointed (Fig. |
Morgenia modulata | Very few, nearly absent (Fig. |
Spaced crossveins (Fig. |
3.0 mm long (100 dense, + ca. 20 widely and ca. 30 evenly spaced) (Fig. |
Slender, apically flattened (Fig. |
Widely concave with right base (Fig. |
Tips gently up-curved (Fig. |
Long but enclosed inside the tibia (Fig. |
We have the pleasure to dedicate this species to the German orthopterologists Arne and Gerlind Lehmann, who collected the only known specimen.
Central African Republic, Dzanga-Ndoki National Park, Mboki (5°18’31”N, 25°57’16”E), 24.I.2012 (light), Sangha2012 team (1♂ holotype,
At the present time, known only from the type locality, Dzanga-Ndoki National Park (Central African Republic).
Head and pronotum yellow-green, antennae yellowish, abdomen yellow-brown, cerci yellow, tegmina with a black line at base, green with brownish stridulatory area. One black spot between tympana of fore tibiae.
Males. Head and antennae. Fastigium of vertex narrow, sulcate above, not contiguous with fastigium of frons. Eyes rounded, well projecting. Antennae longer than body. Legs. Fore coxae armed with a small spine. Fore tibiae furrowed on upper margin, distinctly widening above tympanum, conchate on inner, open on outer side. Fore femora armed on inner ventral side with 3–4 small spines, fore tibiae with 3 spines + 1 spur on inner side and 3 spines + 1 spur on outer ventral side, mid femora with 4–5 spines on outer ventral side, mid tibiae with 6–7 spines on outer and 3–4 on inner ventral sides. The inner ventral spur of mid tibiae is more apically located, short, up-curved and does not exceed the base of the first tarsal article; its length is about 2.5–3.0% the length of tibia. On the outer ventral margin of mid tibiae, three close short spines are present (Fig.
Tegmina of M. angustipinnata sp. n. are very narrow (Table
From Latin angusta = narrow, and pinnata = winged.
Stridulatory area of left tegmen and mirror of right tegmen of the male of Morgenia plurimaculata sp. n. (15), M. angustipinnata sp. n. (16), M. melica (17) and M. modulata (18). Arrows in M. plurimaculata sp. n. and M. angustipinnata sp. n. show the net of small cells in costal area of their tegmina, while in M. modulata the protruding stridulatory area.
Karsch, 1893. Entom. Nachricht. 19 (13): 196.
Type locality: Victoria (Cameroon) (
Cameroon, Victoria (holotype ♂) (
M. melica is known from Cameroon, Democratic Republic of the Congo, Central African Republic, Uganda, Gabon and Ivory Coast (
The left tegmen of M. melica has a small brown spot covering only the stridulatory area, costal area of tegmina has regularly spaced crossveins (Fig.
Karsch, 1896. Stett. Entomol. Z. 57: 340.
Type locality: Lolodorf (Cameroon) (
Cameroon, Lolodorf, L. Conradt (♂, ♀ syntypes, labeled as Morgenia maculata); Johann Albrechtshöhe, L. Conradt (♂, labeled as M. maculata) (
M. modulata is known from Gabon, Cameroon, Central African Republic, Ivory Coast and Togo (Karsch, 1896,
We know very little about morphological differences of the females of species of the genus Morgenia. However, according to
Generally, females are rarely collected; however, it may be the method of collecting these insects (by artificial light during the night) that attracts mainly males and only rarely some females are captured. Overall, both by means of studying material preserved in museums or by collecting in the field, males are always much more numerous than females.
The presence of a spur on the mid tibia of males is already known in other genera of Phaneropterinae (in tropical Africa genera Atlasacris Rehn, 1914, Monticolaria Sjöstedt, 1909, Odonturoides Ragge, 1980 and Meruterrana Sjöstedt, 1912; in tropical America Centrofera bimaculata Brunner von Wattenwyl, 1878). Its origin could be a modified apical spur and probably it appeared several times independently. In the genus Morgenia, the spur may be an apical, very short and up-curved spur in M. angustipinnata sp. n. and M. spathulifera or a sub-apical spur, long and pointed or up-curved in M. hamuligera, M. melica, M. rubricornis and M. lehmannorum sp. n., and short and pointed in M. plurimaculata sp. n.; only in the case of M. modulata, it is very long, not sub-apical or apical located, but enclosed inside the mid tibia. The remarkable difference, evolving in M. modulata, has not been previously noticed.
Where spurs are present on the forelegs of insects, these are generally used to clean antennal segments.
A possible relation between the colour of the stridulatory area and the shape of the spur has been observed: four species with a blackish stridulatory area (M. hamuligera, M. rubricornis, M. melica, M. plurimaculata sp. n.) and only one with a less coloured stridulatory area (M. lehmannorum sp. n.) have a more or less long and pointed or up-curved, sub-apical spur, while the two species with less coloured stridulatory areas (M. angustipinnata sp. n., M. spathulifera) have a short and up-curved apical spur; the sole species with a nearly colourless stridulatory area (M. modulata) has a very modified spur at the mid tibiae. Within the tribe Poreuomenini, other genera may have a blackish coloured stridulatory area (e.g. Cestromoecha Karsch, 1893, Poreuomena Brunner von Wattenwyl, 1878); thus, we can consider that this pattern could be ancestral, even if it appeared independently at different times. If this interpretation is correct, the long and pointed spur at the mid tibiae in Morgenia species could be the ancestral character, while the short and up-curved spur could be a more recent adaptation, a sort of reduction of the character. The very singular shape of the spur in M. modulata remains seemingly inexplicable. It does not seem an adaptation; it changed very probably the original apical position of a modified spur and moved lower down into a new position, where probably it has maintained its function. We were unable to find this kind of modified spur in other genera of Phaneropterinae.
The calling song of the male was recorded only during daytime, from 6 a.m. to 5 p.m. It consisted of isolated, very short syllables (less than 100 ms: 71±6 ms; n=12) which were produced at intervals of about 10 s or longer (Fig.
Comparing the syllable structure with the stridulatory file (Fig.
Analysis of the standard karyotype of Morgenia lehmannorum Heller & Massa sp. n. revealed a diploid chromosome number (2n) of 25 for the male with the X0 sex determination system. Study of the mitotic metaphase showed one large and one small biarmed submetacentric pairs, four medium and six small acrocentric pairs; the X chromosome is metacentric and the largest element in the set. So, the FN (Fundamental Number, the number of chromosome arms including of the X chromosome) of this species = 30. The C-heterochromatin was characterised by paracentromeric C-bands of similar size (Figs
The modal karyotype of Phaneropterinae consists in the male of 31 acrocentric chromosomes, with the X0 sex determination system probably plesiomorphic for the whole Tettigoniidae (e.g.
Barcoding diagnoses separate species from gabonese specimens. The male of M. rubricornis (LopeORT14-617) with BIN: BOLD: ACO0217 has a sequence different from the male of M. melica (LopeORT14-618) with BIN: BOLD: ACN9970. Sequencing of a specimen, LopeORT14-673 did not work but was identified as M. rubricornis by one of the authors (BM). There is not enough data in BOLD or public data for the sequences of Morgenia to be compared with each other. The construction of a neighbour-joining tree of DNA barcodes (COI) was not possible.
Chromosomes of Morgenia lehmannorum sp. n.; C-banded mitotic metaphase (A) and diakinesis (B) as well as silver nitrate staining of diakinesis (C) of male complement. Arrows indicate secondary construction region in the largest arm of biarmed chromosome (b) which correspond to the presence of one active NOR (c). An asterisk indicates biarmed medium and small pairs. X, sex chromosome. Scale bars = 10 µm.
Living specimens of Morgenia hamuligera from Central African Republic, Dzanga-Ndoki National Park (54; photo by P. Annoyer), M. plurimaculata sp. n. from Central African Republic, Dzanga-Ndoki National Park (55; photo by S. Danflous) and M. lehmannorum sp. n. from Uganda, Semliki Forest National Park (56; photo by K-G Heller).
We wish to thank all persons of Sangha Expedition “SANGHA2012 Biodiversité en Terre Pygmée Expedition Team”, Philippe Moretto, who kindly allowed BM to study the material collected during 2012–2017 from central and western African countries, Philippe Annoyer, Président de l’Association Insectes du Monde, et Organisateur de l’expédition Sangha 2012, Matias Loubes, President of the Association Tout là-Haut, Jean-Louis Fijalkowski, for his logistic help in Bangui, the porters and guides who, from Bayanga, accompanied the expedition, the Central African population, partners and all persons who directly or indirectly supported the Sangha project team, Biodiversité en Terre Pygmée, Dieu béni Bongola Omonoma, local collector of insects within the forest during the expedition Sangha 2012 and Cyrille Perez, who participated to the expeditions Sangha in 2010 and 2012. BM very much thanks Philippe Annoyer, Samuel Danflous, Matias Loubes and Philippe Moretto for their collaboration and help during the collecting nights in the Taï National Park (Ivory Coast) in March 2017, both on the ground and at 40 m over a tree of Klainedoxia gabunensis. Philippe Moretto kindly allowed BM to study the material collected during 2012–2017 from central and western African countries. Our thanks also go to Gerlind and Arne Lehmann who collected and presented to K-GH the specimen of a new species from Uganda. For Gabon, fieldwork was supported by University of Rouen, French Embassy at Libreville, Gabon (“Service de Coopération et d’Action Culturelle”) and IRD. Logistical support was provided by WCS (Libreville, Gabon) and CEDAMM (La Lopé, Gabon), Research Station on Gorilla and Chimpanzee (La Lopé, Gabon), the Gabonese Agency for National Parks (Libreville, Gabon).
This research received support to BM from the Synthesys Project, which is financed by European Community Research Infrastructure Action under the FP7 “Capacities” Programme at the Museo Nacional de Ciencias Naturales, Madrid (CSIC) (2013: ES-TAF-2438), the Museum für Naturkunde, Berlin (2014: DE-TAF-4109), the Naturhistorisches Museum, Vienna (2016: AT-TAF-5324), the National Museum, Prague (2016: CZ-TAF-5559) and the Royal Belgian Institute of Natural Sciences, Bruxelles (2017: BE-TAF-6319). BM is especially indebted to Mercedes Paris (Museo Nacional de Ciencias Naturales of Madrid), Michael Ohl (Museum für Naturkunde of Berlin), Susanne Randolf and Harald Bruckner (Naturhistorisches Museum, Vienna), Jérôme Constant (Royal Belgian Institute of Natural Sciences, Bruxelles), Martin Fikáček (National Museum Natural History, Prague), Roberto Poggi, Maria Luisa Tavano and Giuliano Doria (Museo Civico di Storia Naturale ‘G. Doria’ of Genoa), Emanuela Palmisano (Museo Regionale di Palazzo D’Aumale, Terrasini, Palermo), who facilitated the study of specimens preserved in their museums. We are especially indebted to Jürgen Deckert (Museum für Naturkunde, Berlin) for his advice about the types of M. modulata. We thank also Philippe Annoyer and Samuel Danflous, who provided photographs of live specimens.
Collecting authorisations were obtained as follows: 019/UB/DSV2012 of 16.I.2012 from Bangui University, Central African Republic; AE0001/14/MESRS/CENAREST/CG/CST/CSAR of 08.IV.2014 from the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique of Gabon; 135/MESRS/DGRSIT/mo of 12.VI.2015, 238/MESRS/DGRSIT/mo of 13.X.2015, 040/MESRS/DGRSIT/mo of 8.III.2016 from the Ministère de l’Enseignement Superieur et de la Recherche Scientifique of Ivory Coast; 0429/MINEDD/OIPR/DG of 14.VII.2016, 0505/MINEDD/OIPR/DG of 18.VIII.2016 from the Ministère de l’Environnement et du Développement Durable of Ivory Coast; 021/MESRS/DGRI of 15.II.2017 from the Ministère de l’Enseignement Superieur et de la Recherche Scientifique of Ivory Coast.