Oecanthus lineolatus Saussure

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 : 56-58

Oecanthus lineolatus Saussure

Oecanthus lineolatus Saussure, 1897: 254 . Type locality: Brazil, Rio Grande do Sul. A male labeled as syntype in Muséum d'histoire naturelle de Genève.

Male ( Fig. 3 ). Differs from O. pallidus n. sp. by body color, being slightly darker as pale-green, pale-green head with yellow eyes ( Fig. 6, 8 ); femur III translucent/pale-green variegated ( Fig. 10 ); file teeth number 47±2.2 (42–51, n = 18); hindwings non caudate; metanotal gland scutum with two pairs of bristles Fig. 16 , tb; posterior median lobe of scutum as Fig. 16 , pml; no bristles on scutum and scutellun at scutoscutellar suture ( Fig. 16 , ss); scutellun as Fig. 16 , St; supra-anal and subgenital plates as Fig. 17, 19 , respectively; main lobe of pseudepiphallus lenticularshaped, projecting posteriorly ( Fig. 27 ).

Male body measurements (in mm, n = 32). Body length 12.4±1.3 (10.4–15.1); head width: 1.7±0.05 (1.6–1.8); inter ocelli width: 0.7±0.1 (0.5–0.8); pronotum length 2.2±0.1 (2.02–2.5); pronotum width: 2±0.1 (1.8–2.2); hind femur length: 7.8±0.3 (7.4–8.4); hind tibia length–8.3±0.3 (7.7–8.9); tegmen length 12.1±0.3 (11.4–12.6, n = 15). Male phallic sclerites ( Fig. 21–25 ; 27–30). Similar to O. pallidus n. sp., differing in main body of pseudepiphallus.

Calling song ( Fig. 32, 34 ). 20.ii.2011, 21h; 16°C; field recorded; dominant frequency 2570 Hz; chirp duration 0.88 s; chirp period 2.91 s; pulses per chirp 34; pulse rate 39; chirp rate 20.4. Individuals data, and relationship between frequency/pulse-rate and pulse-rate/temperature showed in Tab. 1 , Figs. 35–36 , respectively.

Note: calling song of O. lineolatus and O. pallidus n. sp. showed intraspecific and individual variation in the chirp structure, including amplitude differences in the first pulse and/or failures along the chirp; some were highlighted in Figs. 33 , a, b, c; 34, a, b, c).

Female ( Fig. 4 ). Similar in color to male, slightly larger in size; ovipositor rather robust, tipped with black ( Fig. 38 ); subgenital and supra-anal plates as Fig. 41–42 , respectively; body measurements (in mm, n = 10): body length 11.9±1.2 (10.1–13.3); head width 1.7±0.1 (1.5–1.8); inter ocelli width 0.7±0.04 (0.6–0.8); pronotum length 2.1±0.1 (1.9–2.2); pronotum width 1.8±0.1 (1.6–2.1); hind femur length 7.7±0.2 (7.4–8.2); hind tibia length 8.4±0.3 (7.7–8.9); ovipositor length 5±0.2 (4.7–5.2).

Specimens examined. 36 males and 10 females, municipality of São Lourenço do Sul, district of São João da Reserva, State of Rio Grande do Sul, Southern Brazil 31º17’39.43’’S, 52º09’02.76’’W, 13/ii/2011. A.S. Neutzling leg.

Voucher specimes. 26 males and five females will be kept at collection of the Departamento de Zoologia e Genética, Instituto de Biologia, Universidade Federal de Pelotas (UFPel) and, 10 males and five females at Museu de Zoologia da Universidade de São Paulo (MZUSP).

Habitat and behavior of O. pallidus n. sp. and O. lineolatus . Both species were found in the boundary between tobacco plantation and native shrubs ( Fig. 43 ), preferably dwelling plants of tobacco ( Nicotiana tabacum ) and erva-lanceta ( Solidago chilensis ); hiding immobile during day among the tobacco sprouting leaves and S. chilensis abaxial leaf surface; they were active at night, performing an omnivorous diet, including tobacco leaves, aphids and pollen, latter sometimes was accessed by chewing a hole in the corolla settled at anther position ( Fig. 44 ); they also showed preference for inflorescence, fruits, as well as aphids from leaves of S. chilensis ; males began their calling song at dusk, peaking between 21h to 1h, and reducing activity towards at dawn; preferentially folded tobacco leaves were used as calling song perch ( Fig. 45 ); males also clewed an oval-shaped hole in the center of leaf setting the forewings against its edges to stridulate ( Fig. 46 ); other species of trees and shrubs were also used as perch to stridulate.

Figures

FIGURES 3 – 4. Oecanthus lineolatus. 3 — male, habitus, dorsal view; 4 — 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 21 – 25. Oecanthus lineolatus genitalia. 21 — genitalia, diagonal, 22 — lateral; 23 — phallic sclerites, dorsal; 24 — ventral, 25 — lateral. Conventions: M-End. Sc—Median endophallic sclerite; L-End. Sc—lateral endophallic sclerite; End. Sc. p—endophallic sclerite posterior lobes; Ect. Sc—ectophallic sclerite; Ect. F—ectophallic fold; Dc—dorsal cavity; MLPs—main lobe of pseudepiphallus; R—rami; ss—spermatophore sac; amp—spermatophore ampulla; st—spermatophore

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.

FIGURES 43 – 46. Habitat of O. pallidus n. sp. and Oecanthus lineolatus. 43 — native trees and shrubs bordering tobacco plantation; 44 — Tobacco’s flowers, arrows indicate hole in the corolla; 45 — Oecanthus lineolatus stridulating in the tobacco leaf border, 46 — Oecanthus lineolatus stridulating in a chewed oval-shaped hole in the center of the leaf.