Xenogryllus mozambicus Robillard, 2019

Jaiswara, Ranjana, Dong, Jiajia, Ma, Libin, Yin, Haisheng & Robillard, Tony, 2019, Taxonomic revision of the genus Xenogryllus Bolívar, 1890 (Orthoptera, Gryllidae, Eneopterinae, Xenogryllini), Zootaxa 4545 (3), pp. 301-338 : 328-331

Xenogryllus mozambicus Robillard n. sp.

( Figs 2 A–D, 3K–L, 4H, 5F, 7J–K, 8F, 9D, 11H–J, 12C, 15, 16)

Xenogryllus eniopteroides (wrong spelling of X. eneopteroides )—Toms 1984: 309.

Type material. Holotype, ♂, Mozambique: Cabo Delgado, Pantanos de Nhica, zone herbacée à l’Est du camp [herbaceous area E of camp], 10°45’19,1"S 40°13’00"E, 122 m, 29.xi.2009, T. Robillard, nuit, enregistrement appel [call recording MNHN-SO-2018-140] (TR475) (MNHN-EO-ENSIF1517) . Allotype, ♀, Mozambique: Cabo Delgado, mare SE de Nhica, bras mort de la Rovuma [pond SE Nhica, dead arm of Rovuma river ], 10°45’41,9"S 40°13’31,7"E, 124 m, 27.xi.2009, T. Robillard, mort en élevage [dead in captivity] (MNHN-EO- ENSIF1539) . Paratypes (8♂, 4♀): Mozambique: Cabo Delgado, same information as holotype: 1♂, 1♀, morts en élevage [dead in captivity] (MNHN-EO-ENSIF1576-ENSIF1556). Same information as allotype: 2♂, mort en élevage [dead in captivity] (MNHN-EO- ENSIF1557, ENSIF1508). Mare SE de Nhica, bras mort de la Rovuma [pond SE Nhica, dead arm of Rovuma river], 10°45’41,9"S 40°13’31,7"E, 124 m, nuit, zone herbacée en bord de piste [herbaceous area near track] T. Robillard: 22.xi.2009, 1♂ (MNHN-EO-ENSIF1554), 3♀ (MNHN-EO- ENSIF1502, ENSIF1503, ENSIF1505); 23.xi.2009, 1♂ (TR208), enregistrement appel Take 224 [call recording MNHN-SO-2018-133] (MNHN-EO-ENSIF3079); 1♂ (TR206), enregistrement appel Take 222 [call recording MNHN-SO-2018-134], molecular sample X7 - XenMoz (MNHN-EO-ENSIF1515). Mare SW de Nhica, bras mort de la Rovuma [pond SW Nhica, dead arm of Rovuma river], 10°52’09,5"S 40°06’47,1"E, 122 m, 24.xi.2009, nuit, zone herbacée en bord de piste [herbaceous area near track] T. Robillard: 1♂ (TR224), hautes herbes (h=1.3 m) [on high grass], enregistrement appel Take 228 [call recording MNHN-SO-2018-135], molecular sample X23 (MNHN-EO-ENSIF1559); 1♂, mort en élevage (MNHN-EO-ENSIF1581) .

Additional material examined. Mozambique: Delagoa [Maputo Bay], xii.1898, 1 ♂, identified Phormincter species nova by A. Finot (MNHN). South Africa: Zululand, Mtunzini , 8.i.1952, R. Toms, 1♂, R146, identified Xenogryllus eneopteroides by B. C. Townsend, 1984, B.M.1983-166 ( NHMUK 010926568 ) . Malawi: Fish Eagle Bay Lodge, herbaceous area near lake Malawi ( Mal 7), S13°02'21.1" E34°19'34.8", 503 m, 6.x.2018, night, 2♂, call recording, 1♀, T. Robillard, K. Salazar & R. Murphy ( MNHN) .

Type locality. Mozambique, Cabo Delgado, Pantanos of Nhica , 10°45’19,1"S 40°13’00"E .

Distribution. Mozambique, South Africa, Malawi.

Etymology. Species named after the type locality.

Diagnosis. Species of average to large size, close to X. eneopteroides and X. maniema n. sp. From X. eneopteroides , the new species differs by rather larger size, face more rounded, almost globular in lateral view, absence of T-shaped median band on pronotum (also absent in X. maniema ), larger mirror, and slight differences in male genitalia. From X. maniema n. sp., X. mozambicus mostly differs by male genitalia with larger lophi ( Fig. 8F ) and presence of transverse carina on ventral face of lophi (also present in X. eneopteroides ). As X. maniema and X. eneopteroides , X. mozambicus differs from X. lamottei n. sp. and Asian species by strongly carinated lateral angles of pronotum.

Description. Species of average size ( Fig. 2 A–D), coloration light brown little contrasted. Eyes little prominent laterally ( Fig. 3K ), higher than long, occupying almost half of head height in lateral view. Face globular in lateral view ( Fig. 3L ), with typical whitish mask underlined by a black line below eyes and on mandibles. Pronotum dorsal disc strongly carinated laterally, coloration light brown, with a median dark brown band, not extended laterally near anterior margin; lateral lobes almost homogeneously dark brown. First article of antennae dark brown.

Male. FWs very wide, longer than abdomen; dark coloration anterior to 1A including angle of 1A ( Fig. 5F ). Stridulatory file with 505 teeth (n=1) on transverse part of 1A. FW venation as in X. eneopteroides , mirror wider and apical field longer, forming a long triangle including 5–6 (n=8) cell alignments.

Male genitalia ( Fig. 7 J–K): Similar to X. eneopteroides , except longer pseudepiphallic lophi ( Fig 8F ); transverse carina on ventral face of lophi present but weak.

Female ( Fig. 2 C–D) FW dorsal field elongate, with 8–9 longitudinal veins (m = 9, n = 6). Subgenital plate with a shallow apical indentation ( Fig. 9D ). Ovipositor short, about 0.6 times FIII length.

Female genitalia: Copulatory papilla ( Fig. 11 H–J) as in X. eneopteroides , conical and narrow, well-sclerotized except base and apex.

Life history traits. X. mozambicus lives in areas of wet savannah ( Fig. 15 ) or on the edge ponds and lakes. Individuals of both sexes are found only at night in herbaceous vegetation, and males sing at night from the vegetation (ca. 30–80 cm high). Toms (1984) demonstrated that this species has directional calls and turs while calling, giving rise to changes in sound intensity.

Calling song ( Figs 12C , 16 ). At 21.5 °C, males of X. mozambicus emit almost continuously long bouts of highly musical calling songs. After a warming phase, call bouts are made of successions of echemes of 23 ± 2 syllables, barely separated from each other (echeme duration = 3.13 ± 0.29 s; echeme period 3.21 ± 0.30 s, echeme duty cycle = 97.6 %), with a regular amplitude profile, except for the last syllable, which is more intense. Within echemes, syllables are initially organized in 4 ± 1 doublets, which are followed by a series of similar syllables. Syllables are very long (syllable duration = 126 ± 5 ms), with a relatively short syllable period of 137 ± 8 ms (syllable duty cycle = 92%). All syllables are characterized by a large amplitude modulation: in initial doublets within echemes, the first syllables are less intense than the second ones and they start with a lower amplitude than their end (initial amplitude <ending amplitude), contrary to the second syllables of the doublets (initial amplitude> ending amplitude); the rest of the syllables have a higher starting amplitude, except for the last syllable of each echeme, which has a higher ending amplitude. The frequency spectrum shows a pure-tone dominant frequency at 3.3 ± 0.01 kHz, followed by a rich harmonic content including three powerful harmonics at ca. 6.6, 9.9, 13.2 kHz, especially visible in ending syllables.

Measurements. See Table 7.

Taxonomic discussion. The specimens observed by Toms (1984) and identified Xenogryllus eniopteroides (wrong spelling for X. eneopteroides ) from Zululand (Mtunzini and Eastern Transvaal (Clanor)), South Africa, belong to X. mozambicus n. sp. according to one male specimen observed from the series of Toms (NHMUK 010926568).

Figures

FIGURE 2. (A–D) Xenogryllus mozambicus n. sp.: male in dorsal (A) and lateral (B) views, female in dorsal (C) and lateral (D) views; (E–H) Xenogryllus transversus: male in dorsal (E) and lateral (F) views, female in dorsal (G) and lateral (H) views; (I–L) Xenogryllus ululiu: male in dorsal (I) and lateral (J) views, female in dorsal (K) and lateral (L) views. Scale bar: 1 cm.

FIGURE 3. Heads of Xenogryllus in facial (left panel) and lateral views (right panel): (A–B) Xenogryllus eneopteroides; (C–D) Xenogryllus lamottei n. sp.; (E–F) Xenogryllus maichauensis; (G–H) Xenogryllus maniema n. sp.; (I–J) Xenogryllus marmoratus. (K–L); Xenogryllus mozambicus n. sp.; (M–N) Xenogryllus ululiu; (O–P) Xenogryllus transversus. Scale bar: 1 mm.

FIGURE 5. Male FW venation in dorsal view: (A) Xenogryllus eneopteroides; (B) Xenogryllus lamottei n. sp.; (C) Xenogryllus maichauensis; (D) Xenogryllus maniema n. sp.; (E) Xenogryllus marmoratus; (F) Xenogryllus mozambicus n. sp.; (G) Xenogryllus transversus; (H) Xenogryllus ululiu. Scale bar: 5 mm.

FIGURE 7. Male genitalia: (A–C) Xenogryllus eneopteroides, dorsal (A), ventral (B) and lateral (C) views; (D–E) Xenogryllus lamottei n. sp., ventral (D), lateral (E) views; (F–G) Xenogryllus maniema n. sp., ventral (F), lateral (G) views; (H–I) Xenogryllus marmoratus, ventral (H), lateral (I) views; (J–K) Xenogryllus mozambicus n. sp., ventral (J), lateral (K) views; (L– N) Xenogryllus maichauensis, pseudepiphallic lophi in ventral (L–M) and lateral (N) views, male from South China (L), male from Thailand (M, N); (O–P) Xenogryllus transversus, dorsal (O), ventral (P) views; (Q–R) Xenogryllus ululiu, pseudepiphallic lophi in dorsal (Q) and ventral (R) views. Scale bar: 1 mm.

FIGURE 8. Right pseudepiphallic lophi of male genitalia in dorsal view: (A–B) Xenogryllus eneopteroides, male from Central African Republic (A), male from Ivory Coast (B); (C) Xenogryllus lamottei n. sp.; (D) Xenogryllus maichauensis; (E) Xenogryllus maniema n. sp.; (F) Xenogryllus mozambicus n. sp.; (G) Xenogryllus marmoratus; (H) Xenogryllus ululiu; (I) Xenogryllus transversus. Symbols: Preapical hook-like expansion figured in gray or with a black arrow; dotted parts represent membranous areas; thin lines represent folds and reliefs in sclerites. Scale bar: 1 mm.

FIGURE 9. Apex of female subgenital plate and base of ovipositor in ventral view: (A) Xenogryllus eneopteroides; (B) Xenogryllus marmoratus; (C) Xenogryllus maichauensis; (D) Xenogryllus mozambicus; (E) Xenogryllus transversus; (F) Xenogryllus ululiu. Scale bar: 1 mm.

FIGURE 11. Female copulatory papilla: (A–B) Xenogryllus eneopteroides, in ventral (A) and lateral (B) views; (C–D) Xenogryllus marmoratus, in ventral (C) and lateral (D) views; (E–G) Xenogryllus maichauensis, in ventral (E), dorsal (F) and lateral (G) views; (H–J) Xenogryllus mozambicus n. sp., in ventral (H), dorsal (I) and lateral (J) views; (K–L) Xenogryllus ululiu, in ventral (K) and lateral (L) views; (M–O) Xenogryllus transversus, in ventral (M), dorsal (N) and lateral (O) views. Scale bar: 0.5 mm.

FIGURE 12. Comparison of calling songs, oscillogram of five echemes: (A) Xenogryllus maichauensis; (B) Xenogryllus marmoratus; (C) Xenogryllus mozambicus n. sp.; (D) Xenogryllus transversus; (E) Xenogryllus ululiu. Scale bar: 1 s.

FIGURE 15. (A–D) Xenogryllus mozambicus n. sp.: Savannah habitat in Mozambique (A), male (B) and female (C) in bushy vegetation at night; male (D) predated by Reduviidae sp.

FIGURE 16. Calling song of Xenogryllus mozambicus n. sp.: (A) oscillogram of 5 echemes; (B) detailed oscillogram (upper panel), amplitude envelope (middle panel) and sonogram (lower panel) of 1 echeme; (C) detailed oscillogram (upper panels) and sonograms (lower panels) of one the two initial syllables (left) and of the final syllable (right); (D) frequency spectrum.