Oecanthus pallidus Zefa

Zefa, Edison, Neutzling, Alexandre Schneid, Redü, Darlan Rutz, Oliveira, Gabriel Lobregat De & Martins, Luciano De Pinho, 2012, A new species of Oecanthus and Oecanthus lineolatus Saussure, 1897 from Southern Brazil: species description, including phallic sclerites, metanotal glands and calling song (Orthoptera: Gryllidae: Oecanthinae), Zootaxa 3360, pp. 53-67 : 55-56

Oecanthus pallidus Zefa , n. sp.

( Fig. 1, 2 )

Etymology. The specific epithet refers to pale body color.

Holotype. Male; Brazil, State of Rio Grande do Sul, Municipality of São Lourenço do Sul, district of São João da Reserva, 31º17’39.43’’S, 52º09’02.76’’W, 12/ii/2012, A. S. Neutzling leg.

Paratypes. 12 adult males, 12/ii/2012; Brazil, State of Rio Grande do Sul, Municipality of São Lourenço do Sul, district of São João da Reserva, 31º17’39.43’’S, 52º09’02.76’’W, A.S. Neutzling leg.

Description. Male ( Fig. 1 ). Body slender and pale green. Head pale-yellow and glabrous; clypeus and labrum whitish; maxillary palpi moderately elongate with five joint, first and second joints smaller then the other three, third to fifth joints subequal in size, latter fusiform and depressed at inner side ( Fig. 5 ); joints of labial palpi with gradual increase in size toward apex; scape and pedicel marked by a longitudinal black line outlined in white; moderately prominent greenish-white eyes ( Fig. 7 ), ocelli absent. Pronotum slightly pubescent with slender bristles on the border; tibiae I unarmed, swollen near base and mounted each side with an elongated-oval tympanum ( Fig. 9 , t); three-jointed tarsi I, basitarsus longer than two others together; tibiae and tarsi II same as tibiae I, without tympanum; femur III uniformly whitish green; tibiae III armed above on each margin with a row of small spines; three to five inner and three to five outer subapical spurs; there are spines between subapical spurs; three apical spurs at outer side ( Fig. 11 , a–c) and four at inner side of the tibiae ( Fig. 12 , d–g); spurs and spines tipped with black; proximal joint of the tarsi III longer than the two others, the middle joint is the smallest one. Tegmina little sclerotinized ( Fig. 13 ), projecting beyond the abdomen; dorsal field translucent allowing to see hindwings; three crossveins in the harp and two in the mirror; file teeth number 32.8±1.2 (31–34, n = 6); hindwings caudate. Scutum of the metanotal gland with two pairs of bristles tuft ( Fig. 15 , tb); posterior median lobe of scutum as Fig. 15 , pml; no bristles on scutum and scutellun at scutoscutellar suture ( Fig. 15 , ss); scutellun as Fig. 15 , St; greenish-white abdomen tergites, sternites lighter then tergites, cerci slender, pale-green, tipped with black; supra-anal and subgenital plates as Fig. 18, 20 , respectively.

Male phallic sclerites. Median ectophallic sclerite connected to the dorsal cavity; lateral endophallic sclerite posteriorly bilobed and anteriorly bifurcated, inner branch slightly connected to ectophallic sclerite; ectophallic sclerite posteriorly bifurcate with inner branch connected forming an ectophallic fold, and outer placed between posterior lobes of the endophallic sclerite; main lobe of pseudepiphallus triangular and projecting posteriorly ( Fig. 26 ), with a median U-shaped invagination; rami fused proximad, pseudepiphallic apodemes present.

Male body measurements (in mm, n = 9). Body length 10.9±0.8 (9.7–10.9); head width 1.5±0.05 (1.4–1.5); inter ocelli width 0.6±0.1 (0.5–0.6); pronotum length 1.7±0.1 (1.5–1.7); pronotum width 1.6±0.1 (1.5–1.6); hind femur length 7.6±0.4 (6.9–7.6); hind tibia length 8.5±0.5 (7.7–8.5); tegmen length 11.1±0.4 (10.6–11.6, n=6).

Holotype calling song ( Fig. 31, 33 ). 12.ii.2012, 0h02min; 16°C; field recorded; dominant frequency 2184 Hz; chirp duration 1.98 s; chirp period 5.29 s; pulses per chirp 83; pulse rate 43; chirp rate 11.4.

Paratypes calling song data, and relationship between frequency/pulse-rate and pulse-rate/temperature showed in Tab. 1 , Figs. 35–36 , respectively.

Female ( Fig. 2 ). Similar to male with the following exceptions: slightly larger in size, ovipositor rather robust, tipped with black ( Fig. 37 ); subgenital and supra-anal plates as Fig. 39, 40 , respectively; body measurements (in mm, n = 3): body length 11.1±0.7 (10.3–11.8); head width 1.5±0.01 (1.52–1.55); inter ocelli width 0.7±0.05 (0.6–0.7); pronotum length 1.8±0.2 (1.7–2); pronotum width 1.6±0.1 (1.6–1.7); femur III length 7.9±0.45 (7.3–8.2); tibia III length 8.9±0.42 (8.5–9.4); ovipositor length 4.7±0.31 (4.4–4.9).

Diagnosis. Resulting from the combination of characteristics that follow: head pale-yellow and subtly contrasting with whitish-green body color, greenish-white eyes; scape and pedicel both marked by a white spot bearing a longitudinal black line; metanotal gland features as Fig. 15 ; file teeth number 32.8±1.2 (31–34, n = 6); calling song at 16°C (dominant frequency 2184 Hz; chirp duration 1.98 s; chirp period 5.29 s; pulses per chirp 83; pulse rate 43; chirp rate 11.4), considering relationship between dominant frequency/pulse-rate and pulse rate/temperature; hindwings caudate.

Depository. Holotype male and six paratypes will be kept at Museu de Zoologia da Universidade de São Paulo (MZUSP). Six paratypes will be deposited at collection of the Departamento de Zoologia e Genética, Instituto de Biologia, Universidade Federal de Pelotas (UFPel).

Figures

FIGURES 1 – 2. Oecanthus pallidus n. sp. 1 — holotype male, habitus, dorsal view; 2 — female, habitus, dorsal view

FIGURES 5 – 8. Male head, dorsal. 5, 7 — Oecanthus pallidus n. sp.; 6, 8 — Oecanthus lineolatus. Arrow: maxillary palpi fifth joint depression.

FIGURES 9 – 14. Legs and tegmina. 9 t— Oecanthus lineolatus tympanum, 10 — hind femur, 11 a, b, c—outer apical spurs, 12 d, e, f, g—inner apical spurs; 13 — Oecanthus pallidus n. sp. right tegmen, dorsal; 14 — Oecanthus lineolatus right tegmen, dorsal.

FIGURES 15 – 16. Metanotal glands. 15 — Oecanthus pallidus n. sp.; 16 — Oecanthus lineolatus. Conventions: Sc—scutum; St—scutellum; ss—scutoscutellar suture; tb—tuft of bristles; pml—posterior median lobe.

FIGURES 17 – 20. Male subgenital and supra-anal plates. 17 — Oecanthus lineolatus supra-anal plate, 19 — subgential plate; 18 — Oecanthus pallidus n. sp. supra-anal plate, 20 — subgential plate.

FIGURES 26 – 30. Oecanthus phallic sclerites. 26 — Oecanthus pallidus n. sp. pseudepiphallus, dorsal; 27 — Oecanthus lineolatus pseudepiphallus, dorsal, 28 — posterior lobes of the endophallic sclerite, diagonal, 29 — endophallic sclerite, dorsal, 30 — ectophallic sclerite, dorsal. Conventions: End. Sc. p—posterior lobes of the endophallic sclerite; MLPs—main body of pseudepiphallus; R—rami; Ps. Ap—pseudepiphallic apodemes; arrows—ectophallic sclerite outer branch settled between posterior lobes of endophallic sclerite.

FIGURES 31 – 36. Calling songs of Oecanthus pallidus n. sp and Oecanthus lineolatus. 31 — spectrogram of Oecanthus pallidus n. sp.; 32 — spectrogram of Oecanthus lineolatus; 33 — oscillograms of Oecanthus pallidus n. sp., a – chirp beginning with two isolated pulses (arrow), b – amplitude variation in the first pulse (arrow), c – broken chirp (arrow); 34 — oscillograms of Oecanthus lineolatus, a – broken chirp (arrow), b – regular train of pulses, c – amplitude variation in the first pulses (arrow), A – chirp first pulse, B – chirp last pulse, C – chirp duration, D – chirp period; 35 — regresson lines showing the effect of temperature on pulse rate for both species; 36 — relationship between pulse rate and frequency in both species.

FIGURES 37 – 42. Ovipositor, subgenital and supra-anal plates. 37 — Oecanthus pallidus n. sp. ovipositor, dorsal, 39 — subgenital plate, 40 — supra-anal plate; 38 — Oecanthus lineolatus ovipositor, dorsal, 41 — subgenital plate, 42 — supra-anal plate.