Miogryllus itaquiensis Orsini & Zefa

Orsini, Marcelo Pinheiro, Costa, Maria Kátia Matiotti Da, Szinwelski, Neucir, Martins, Luciano De Pinho, Corrêa, Robson Crepes, Timm, Vitor Falchi & Zefa, Edison, 2017, new species of Miogryllus Saussure, 1877 and new record of Miogryllus piracicabensis Piza, 1960 (Orthoptera: Gryllidae) from State of Rio Grande do Sul, Brazil, with calling song and chromosome complement, Zootaxa 4290 (3), pp. 547-558 : 548-552

Miogryllus itaquiensis Orsini & Zefa , n. sp.

( Figs 1 , 3–11 )

Type material. Holotype ♂, code (MW02): Brazil, State of Rio Grande do Sul, municipality of Itaqui , 29°8’4.870”S, 56°32’27.190”W, 15.i.2015, M. Dias leg. MZUSP . Holotype condition: genitalia were detached and placed in a small Eppendorf, and right leg III was detached, both were maintained in holotype's tube. Paratypes: same data of Holotype (2♂ and 6♀, MZUSP) .

Etymology. Specific epithet refers to the type locality: municipality of Itaqui, State of Rio Grande do Sul, Brazil.

Diagnosis. Combination of the following characteristics: head with same width than pronotum; gena with a white spot punctuated in brown posteriorly; tegmen reaching 2/3 of the abdomen, and apical area developed; calling song alternating chirps and trills.

Description, Holotype ³ (Code MW02, Figs 1 , 3–11 ). Body black in dorsal, and whitish ventrally. Head: black, bright and glabrous, whitish spot contouring posteriorly the scape and following the inner margin of the eyes, becoming punctuated in brown, with a white strip before reaching occiput; black eyes outlined in white; three well developed ocelli arranged in line, with median ocellus slightly shifted down, lateral ones lighter and bigger; four occipital whitish stripes, lateral ones bifurcate; gena with a white spot punctuated in brown posteriorly; clypeus and labrum brown; mandibles yellow; antenna uniformly light brown; maxillary palpus whitish, five–jointed, moderately elongate, joints 1–2 same–sized, joints 3 slightly longer than 4, joint 5 claviform, ventrally compressed; labial palpus whitish, three–jointed, gradual increase in size toward the apex, third claviform. Thorax: pronotum black, pubescent, dorsal disc wider than long, bristles on the anterior and posterior margins; lateral lobe marked with a antero-ventral whitish spot, which becomes light brown posteriorly, lateral lobe dorsal slightly marked with whitish spot punctuated with dark brown; tegmina covering two thirds of the abdomen, and apical field well developed; mesothorax wings surpassing the abdomen tip; legs I and II punctuated in dark brown dorsally, and whitish ventrally; tibia I with two apical spurs on both outer and inner sides, the outer ones longer than inner, auditory tympanum present on both sides subequal, tarsomere 1 longer than tarsomeres 2–3 together; leg II slightly darker than leg I, with apical spurs longer than leg I; femur III robust, darker dorsally and striped on outer side; tibia III unserrulated, armed with five outer subapical spurs, the proximal one smaller, and four inner subapical spurs, three inner and four outer apical spurs, mesad longer, tarsomere 1 serrulated armed with two apical spurs, the inner longer than outer. Abdomen: Tergites black, sternites whitish, cerci light brown as long as femur, subgenital plate black, conic–shaped, supranal plate trapezoidal bearing median lateral pointed projections.

Phallic sclerites ( Figs 9–11 ). Main lobe of pseudepiphallus with an U–shaped indentation, with apex slightly bent inward; rami slightly sinuous, not fused proximad, apex bifurcated, pseudepiphallic apodemes present, pseudepiphallic parameres bilobed; ectophallic arc and ectophallic apodeme show a W–shaped at dorsal view, ectophallic fold tapers abruptly to a pointed apex; endophallic cavity large.

Calling song ( Figs 17–18 ). Recorded in laboratory, 18°C, 7 a.m., 08.xii.2016; calling song alternating chirps (section A) and trills (section B); section A: period, 0.14 ± 0.01s (0.124–0.17, n = 30); chirp rate, 8 chirps/s; 5 to 8 pulses per chirp, being 1.4% with five pulses, 15.5% with six pulses, 73.2% with seven pulses, and 9.86% with eight pulses; section B: pulse rate, 76 pulses/s. Dominant frequency, 7640Hz.

Measurements (mm). Body length, 15.9; pronotum width, 4.5; pronotum length, 2.1; head width, 4.2; interocular distance, 3.2; femur III length, 9.2; tibia III length, 6.5.

Observations of Paratypes. Hind legs. All paratypes possessed five inner and outer subapical spurs.

Phallic sclerites. Apex of the main lobe of the pseudepiphallus varying slightly in the inward bent; may occurs ectophallic fold not truncated at base, and tapering gradually.

Rigth tegmen ( Fig. 12–14 , n = 2). Dorsal field length, 9.43 ± 0.6mm (9–9.85), dorsal field width, 3.34 ± 0.23mm (3.18–3.5), lateral field length, 7.73 ± 0.86mm (7.12–8.34), lateral field width, 2.71 ± 0.12 mm (2.63–2.8), six accessory veins on lateral field, distal one rising from the subcostal vein; harp area, 6.33 ± 0.7mm 2 (5.83–6.82), with two cross veins; mirror area, 2.89 ± 0.15mm 2 (2.78–2.99) with one cross vein; file length, 2.17 ± 0.127mm (2.08–2.26); teeth number, 98.5 ± 7.78 teeth (93–104).

Calling song. Paratype MW03, recorded in laboratory, 21°C, 6 a.m., 29.xii.2016; section A: chirp period, 0.14 ± 0.229s (0.109–0.221, n = 30); chirp rate, 7.9 chirps/s; 5 to 8 pulses per chirp, being 14.5% of chirps with five pulses, 27.3% with six pulses, 34.5% with seven pulses, and 23.6% with eight pulses; section B, pulse rate 79 pulses/s; dominant frequency, 7127Hz.

Female ( Figs 2 , 15–16 ). Body shape and color pattern similar to Holotype; subgenital plate trapezoid; ovipositor slightly longer than femur III, apex lanceolated.

Measurements (mm). Male (n = 2): body length, 15.5 ± 1.51 (14.4–16.5); pronotum width, 4.1 ± 0.53 (3.7–4.5); pronotum length, 2.3 ± 0.39 (2–2.6); head width, 3.9 ± 0.31 (3.7–4.1); interocular distance, 2.7 ± 0.15 (2.6–2.8); femur III length 9.2 ± 0.17 (9.1–9.3); tibia III length 6.6 ± 0.47 (6.2–6.9). Female (n = 6). body length, 17.6 ± 1.26 (15.8–19.4); pronotum width, 4.8 ± 0.25 (4.4–5.1); pronotum length, 2.5 ± 0.38 (2.04–3.01); head width, 4.2 ± 0.37 (3.7–4.8); interocular distance, 3.1 ± 0,39 (2.6–3.7); femur III length, 9.6 ± 0.58 (8.8–10.3); tibia III length, 6.7 ± 0.37 (6.1–7.2); tegmen length, 8.7 ± 0.4 (8.1–9.3); tegmen width, 3.1 ± 0.26 (2.6–3.3); ovipositor length, 10.6 ± 0.88 (9.2–11.6).

Karyotype ( Fig. 35 ). Diploid chromosome number of 2n = 24 + X ♂ = 25, and 2n = 24 + XX ♀ = 26; two pairs of metacentric chromosomes (pair 1, ci = 50, with secondary constriction in p arm, which left a small satellite at the chromosome tip; pair 4, ci = 42.8), six pairs of submetacentric (pair 2, ci = 35.1; pair 3, ci = 36.4; pair 5, ci = 17.1; pair 6, ci = 34.6; pair 7, ci = 25; and pair 10, ci = 17.9), and four pairs of acrocentric (pair 8, ci = 12.1; pair 9, ci = 11.8; pair 11, ci = 12; and pair 12, ci = 10). The X chromosome is metacentric (ci = 50), and the largest of the complement.

Figures

FIGURES 1 – 2. Habitus of Miogryllus itaquiensis n. sp. in vivo. 1 — male Holotype; 2 — female paratype.

FIGURES 3 – 11. Morphological characteristics of Miogryllus itaquiensis n. sp. holotype. 3 – 5 — habitus after alcohol fixation, in dorsal, ventral and lateral views, respectively; 6 — head, lateral view; 7 — supranal plate; 8 — subgenital plate; 9 – 11 — phallic sclerites, ventral, dorsal and lateral view, respectively. Conventions: MLPs—main lobe of pseudepiphallus; Ect. F—Ectophallic Fold; Ect. Ap. — Ectophallic Apodeme; Arc—Ectophallic Arc; Ps. P—Pseudoepiphallic Paramere; Ps. Ap—Pseudepiphallic Apodeme; End. C—Endophallic Cavity; R—Ramus.

FIGURES 17 – 20. Calling songs of Miogryllus itaquiensis n. sp. and Miogryllus piracicabensis Piza, 1960. 17 – 18 — Holotype oscillogram and spectrogram, respectively; 19 – 20 — oscillogram and spectrogram of Miogryllus piracicabensis.

FIGURES 12 – 16. Morphological characteristics of Miogryllus itaquiensis n. sp. paratypes. 12 — male right tegmen; 13 – 14 — stridulatory file; 15 — female subgenital plate, cerci and ovipositor; 16 — female supranal plate.

FIGURES 35 – 36. Karyotype of Miogryllus. 35 — Miogryllus itaquiensis n. sp.; 36 — Miogryllus piracicabensis Piza, 1960.