Gonamytta deboisselae, Guta & Macamo & Naskrecki, 2021

Guta, Ricardo, Macamo, Laura & Naskrecki, Piotr, 2021, A new Gonamytta katydid from central Mozambique (Orthoptera: Tettigoniidae: Meconematinae), Zootaxa 5027 (1), pp. 120-126 : 122-126

Gonamytta deboisselae sp. n.

( Figs. 1–3 )

Type locality. MOZAMBIQUE: Sofala, Gorongosa National Park, Mt. Gorongosa, Tambarara (-18.51161, 34.07949), 815 m, 5.ix.2020, coll. P. Naskrecki —male holotype ( EOWL)

Differential diagnosis. This new species appears to be most closely related to Gonamytta scrofina (Beier) stat. nov. from northern Zambia. It differs in the shape of the male cerci, which are proportionally thicker and significantly more curved upwards in G. scrofina (fig. 2G); the modification of the male 10th tergite, which is deeply and broadly recessed in G. scrofina but only moderately so in the new species; and the venation of the tegmen, which carries a bifurcated vein Rs in G. deboisselae (fig. 1C) but is forked 4 times in G. scrofina . From G. hintheliana , known only from the female holotype and the female holotype of its junior synonym Amytta planicollis Chopard ( Beier 1965) (fig. 1I), it differs in the shorter, more rounded female subgenital plate (fig. 1F); and from G. occidentalis it differs in the structure of the male cerci that are significantly less narrowed and curved apically (fig. 2H).

Genetic barcode. The sequence of the cytochrome c oxidase subunit I gene (COI) with 654 bp was submitted to GenBank with the accession number MZ398138

General. Body small, slender, cylindrical, macropterous (figs. 1G, H).

Head.— Fastigium of vertex triangular, blunt apically, almost reaching tip of scapus, flat dorsally; antennal scapus unarmed; antennae about twice as long as body; frons slightly convex, oblique; eyes globular, moderately protruding.

Thorax. Pronotum surface smooth, lateral lobe twice as long as high; humeral sinus of pronotum present, anterior margin of pronotum flat; metazona flat, its posterior edge narrowly rounded. Sternum flat, prosternum unarmed.

Legs. Legs slender. Front femur unarmed ventrally, in cross section round dorsally but flat ventrally; genicular lobes unarmed; front tibia unarmed dorsally, with 6 spines (including apical one) on posterior and 4 on anterior ventral margin; tympanum bilaterally open. Mid femur unarmed ventrally; genicular lobes unarmed; mid tibia not noticeably thickened in proximal section, unarmed dorsally, with 5 spines on posterior and 5 on anterior ventral margin. Hind femur unarmed ventrally; genicular lobes unarmed; hind tibia armed on both dorsal and ventral margins, spines on ventral margins smaller and more sparsely distributed; dorsal spines of hind tibia of equal size on both edges.

Wings. Tegmen surpassing apex of hind femur; anterior margin straight; hind wing slightly longer than tegmen. Costal field of tegmen wide, gradually narrowing towards wing tip, ending at 3/4 of tegmen; veins Sc and R close together, parallel along their entire length; Rs branching off before middle of tegmen, with 2 apical branches; vein R1 branching of in apical third of tegmen, with 2 apical branches (fig. 1C); right stridulatory area with small but well-developed mirror (fig. 1B); left stridulatory area with small, roughly trapezoidal mirror (fig. 1A). Stridulatory file elevated on thickened vein, weakly bent, with 72 teeth, 0.81 mm long, 0.038 mm wide (fig. 1D).

Abdomen.— Epiproct small, triangular; 10th tergite with posterior edge with shallow, triangular incision; cercus unarmed, long and slender, evenly bent inwards and upwards (figs. 2A–C); paraprocts unmodified; sclerotized epiphallus sclerotized, bulbous, covered with minute scales; its apical part visible externally (figs. 2D–F). Subgenital plate broadly trapezoidal; styli cylindrical, about 4 times as long as wide and as long as 1/5 of subgenital plate, slightly convergent.

Ovipositor. Ovipositor slender, straight, shorter than hind femur; dorsal edge of upper valvula smooth, parallel to lower valvula; apex pointed, with both valvulae smooth (fig. 1E).

Coloration. Coloration light green; antennal scapus without markings, antennae concolorous; eyes uniformly colored, brown; face without any markings; occiput without markings, prozona green. Tegmen green with brown posterior edge; hind wing hyaline; genicular lobes of front legs without markings; hind femur uniformly colored; abdominal sterna and subgenital plate without markings.

Bioacoustics. The call of G. deboisselae is high duty, consisting of a long, uninterrupted train of short syllables (mean syllable duration 0.01513 s, SD= 0.00135; n=140) at the rate of 35.5 syllables/sec (at 22°C), with the frequency peak at 38.2 kHz and a strong harmonic at 114.7 kHz (fig. 3). The call is largely ultrasonic and thus inaudible to the human ear.

Measurements (1 male, 3 females). body w/wings: male 29.62, female 29.57–30.43 (30±.6); body w/o wings: male 16.26, female 23.65–23.71 (23.7±0); pronotum: male 4.47, female 4.3–5.55 (4.9±.6); tegmen: male 21.72, female 21.05–22.24 (21.8±.7); hind femur: male 11.92, female 11.97–12.52 (12.2±.3); ovipositor: 10.4–11.33 (10.9±.5) mm.

Distribution and natural history. This new species is currently known only from Serra Gorongosa, a large mountain covering approximately 700 km 2 and with the highest peak at 1,863 m, and whose relict montane rainforest is isolated from the nearest similar habitats in the Eastern Highlands of Zimbabwe by over 100 km. Considering the level of isolation of the mountain and its forest habitat, the newly described species is potentially endemic to that area. It has been collected from elevations between 815 and 1,134 m, primarily in riverine forests along Rio Murombodzi and at the edges of shade-grown coffee plantations on the lower slopes of the mountain. It is likely that this species also occurs in the remaining stands of the evergreen moist forest higher on the mountain slopes. Adults of G. deboisselae start appearing shortly before the end of the dry season and the onset of first rains, which usually start in early September on Serra Gorongosa, thus at least two months before the onset of first rains in the lowlands of Gorongosa N.P. ( Tinley, 2020).

Etymology. This species is named in honor of Ms. Camille Granger Joly de Boissel for her help in acquiring the specimens used in this study and for her contribution towards restoration of natural habitats on Mt. Gorongosa.

Material examined (9 specimens). Mozambique: Sofala, Gorongosa, PNG, Mt. Gorongosa, coffee plantation, Plot 2_1 year, elev. 925 m (-18.28522, 34.02448), 1.xi.2020, coll. R. Guta — 1 female (paratype) ( EOWL) ; PNG, Mt. Gorongosa , forest trail, elev. 1,112 m (-18.46519, 34.05173), 21.vii.2015, coll. P. Naskrecki & M. Prager —1 nymph female, 2 nymph males ( MCZ) ; PNG, Mt. Gorongosa, Tambarara , elev. 1134 m (-18.512062, 34.090258), 15.viii.2020, coll. C. de Boissel — 1 female (paratype) ; same locality, 5.ix.2020, coll. P.Naskrecki — 1 male (holotype) ( EOWL) ; PNG, Murombodzi Waterfall, nr. Mt. Gorongosa , elev. 842 m (-18.483361, 34.042944), 21.vii.2015, coll. P. Naskrecki —1 nymph female, 1 nymph male ; same locality, 17.x.2018, coll. P. Naskrecki — 1 female (paratype) ( MCZ) .

Other material examined. Anepitacta scrofina Beier : Zambia [N. Rhodesia], Abercorn 6.vii.1952 (holotype) ( BMNH) ; Gonamytta occidentalis (Karsch) : Cameroon: Kribi , xii.1888, coll. Morgan — 1 female (holotype) ( ZMBH) ; Ghana: Eastern Region, Ajenjua Bepo Forest Reserve , elev. 300–320 m (6.366667 -1.016667), 26– 30.viii.2006, coll. P. Naskrecki, V.Awotwe-Pratt and M. Bakowski — 14 females, 13 males ; Mamang Forest Reserve , elev. 130 m (6.250233 -1.033333), 30.viii.–5.ix.2006, coll. P. Naskrecki, V. Awotwe-Pratt and M. Bakowski — 1 male ( MCZ) ; Amytta planicollis Chopard : Guinea: Mount Nimba , elev. 1000 m, 11.vi.1942, coll. M. Lamotte — 1 female (holotype) ( MNHN) .

Figures

FIGURE 1. Gonamytta deboisselae sp. n.: A. male left stridulatory area; B. right stridulatory area; C. male left tegmen; D. stridulatory file; E. ovipositor; F. female subgenital plate; G. male; H. female; I. subgenital plate of the female holotype of Amytta planicollis Chopard.

FIGURE 2. Gonamytta deboisselae sp. n.: A. male cerci, dorsal view; B. ditto, ventral view; C. ditto, lateral view; D. sclerotized epiphallus, ventral view; E. ditto, lateral view; F. male abdominal apex, posterior view; G. G. scrofina, male cerci, lateral view (from Beier 1965); H. G. occidentalis, male cerci, ventral view.

FIGURE 3. Sonograms of Gonamytta deboisselae sp. n.: A. waveform of 5 sec call; B. waveform of a 0.5 sec call fragment; C. spectrogram of a 0.5 sec song fragment; D. frequency spectrum.