Oecanthus pictus Milach & Zefa

Milach, Elisa Machado, Martins, Luciano De P., Costa, Maria Kátia Matiotti Da, Gottschalk, Marco Silva, Oliveira, Gabriel Lobregat De, Redü, Darlan Rutz, Neutzling, Alexandre Schneid, Dornelles, José Eduardo Figueiredo, Vasconcellos, Lucas Azevedo & Zefa, Edison, 2015, A new species of tree crickets (Orthoptera, Gryllidae, Oecanthinae) in tobacco plantation from Southern Brazil, with body color variation, Zootaxa 4018 (2), pp. 266-278 : 268-274

Oecanthus pictus Milach & Zefa , n. sp.

Type material. Holotype ♂: Brazil, Rio Grande do Sul, São Lourenço do Sul, São João da Reserva, 31º17’39.43’’S, 52º09’02.76’’W, 19.iii.2011, D.R. Redü leg., calling song R07 (OSF), MZUSP. Paratypes: same data of Holotype (10♂, 5♀, MZUSP). Same data 19.iii.2011. A.S. Neutzling, D.R. Redü & G.L. Oliveira leg. / R01, R04, R05, R18 (4♂, MZUSP). Same data 20.iii.2011. A.S. Neutzling, D.R. Redü & G.L. Oliveira leg. / GG05, GG07, GG09, R06, R08, R09, R11, R12, R13, R14, R15, R17, R19, R20, R21, R22, R25, R26, GG06, GG10, GG11, GG12, GG14 (23♂, MZUSP). Same data 21.iii.2011. A.S. Neutzling, D.R. Redü & G.L. Oliveira leg. / R29 (1♂, MZUSP). Same data 26.iii.2011, A.S. Neutzling, D.R. Redü & G.L. Oliveira leg. / W01, W02, W03, W04, W06, W07, W08, W09, W10, W11 (10♂, MZUSP). Same data 27.iii.2011. Neutzling, D.R. Redü & G.L. Oliveira leg. / W12, W14 (2♂, MZUSP). Same data 19.iii.2011. Neutzling, D.R. Redü & G.L. Oliveira leg. / (41♂, 5♀, INPA).

Etymology. The specific epithet refers to the black dots on body and appendages (from latim pictus = dotted).

Diagnosis. Combination of the following characteristics: paired postocular lines; L-shaped pedicel mark; tibia I and II proximal to distal marked with three dots, followed by an incomplete ring, plus three dots and four pairs of dots; abdomen tergites with a pair of transversal strips reducing in intensity backward; scutum posterior median lobe indented; pseudepiphallic main lobe V-shaped indented; endophallic sclerite anteriorly bifurcated, outer branch truncated; ectophallic sclerite posteriorly V-shaped.

Description, male holotype ( Figs 5–12 ). Body slender, light green, punctulated; Head glabrous; clypeus and labrum whitish; gena with pigmentar strips; frons with bristles; ecdysial suture pigmented, with short bristles; group of bristles above the eyes; occiput with a pair of parallel stripes posterior each eyes; green eyes in vivo, but black eyes outlined of depigmented ommatidia when fixed in alcohol, depigmented ommatidia where lies the scape; ocelli absent; J-shaped marked scape, L-shaped marked pedicel, antennae flagellum alternating four times two thinner pingmentar ring with a thicker one, pattern is lost toward apex; maxillary palpi moderately elongate with five joints, first and second subequal, smaller than the other three, marked with an incomplete pigmentar ring, third to fifth subequal, third with ventral strip, fourth with incomplete basal ring, and ventral strip, fifth fusiform, depressed at inner, with incomplete basal ring, and an apical diagonal complete ring; labial palpi three-jointed, gradual increase in size toward apex, pigmentar mark at apex, third claviform, incomplete pigmentar ring at base and apex. Thorax: pronotum slightly pubescent, pigmented, translucent, longer as wider, bristles on the border; tegmina translucent, longer than the abdome; hindwings short, reaching first two abdominal tergites; femur I dotted in dorsal face; tibia I proximal to distal marked with three dots, followed by an incomplete ring, plus three dots and four pairs of dots, unarmed, swollen near base and mounted each side with an elongated-oval tympanum, inner longer (0.44mm) than the outer (0.35mm); tarsus I three-jointed, basitarsus lighter and longer than two others together; leg II with the same pattern of leg I, without tympanum; femur III dotted in dorsal face; tibia III same marks pattern of tibia I, serrulated, armed with three pairs of subapical spurs tipped with black; there are black spines between subapical spurs; three apical spurs at outer and four at inner face of the tibia III; basitarsus longer than the two others together, armed with two subequal, apical, tipped with black spurs; the median tarsus the smallest. Abdomen: tergites with a pair of transversal strips reducing in intensity backward; cerci slender, shorter (2.25mm) than the abdomen (5.86mm), marked with a subapical light brown ring; supranal plate translucent, rounded posteriorly, margin with long bristles; subgenital plate rounded posteriorly, with short lateral protuberance.

Metanotal Gland ( Figs 9 , 13–14 ) pit wide, scutum with a pair of inflated protuberance, each including a tuft of bristles projected medio-anteriorly ( Fig. 13 , a), a dense tuft of long bristles projected medio-posteriorly ( Fig. 13 , b), and a tuft of short bristles projected dorso-posteriorly ( Fig. 13 , c); posterior median lobe with median indentation, pubescent ( Fig. 14 , pml); scuto-scutellar suture slightly sinuous, without bristles ( Fig. 13 , ss); scutellum with latero-posterior bristles. Measurements cavity area 0.47mm ²; scutum area 0.89mm ²; scutellum area 0.34mm ²; total gland length 1mm; total gland width 1.43mm; scutum lenght 0.75mm; scutum width 1mm; scutellum length 0.25mm; scutellum width 1.28mm.

Right Tegmen ( Fig. 10 ). Lateral field width, 3.42mm; lateral field length, 6.83mm; 12 acessory veins; dorsal field projected beyond abdomen; basal area reduced, including veins 1A, 2A, 3A and Cu2, last forming the file with 47 teeth ( Fig. 7 ); file length, 0.86mm; chordal area bearing the veins 2A, 1A e Cu2; harpa area, 3.42mm ², harp with three cross veins slightly sinuous; mirror area, 8.65mm ², mirror with two straight cross veins; apical area reduced.

Calling song ( Figs 15–17 ). Field recorded in 19.iii.2011, at 19h30, ambient temperature at 14ºC; trill with dominant frequency of 2422 Hz, pulse period of 0.037s, and pulse rate of 28 pulses/second.

Observations in Paratypes. There were four groups of body color pattern in O. pictus n. sp.: group 1, light yellow-green, and very light dotts ( Fig. 1 ); group 2, light green, and dark dotts ( Fig. 2 ); group 3, green, and dotts darker than group 2 ( Fig. 3 ); and group 4, green-brown, and dotts more intense than the group 3 ( Fig. 4 ).

Legs I, II and III punctulated ( Figs 23–25 ); tibiae I and II proximal to distal (dorsal view) with three marks forming, followed by an incomplete ring, plus three marks, and then three or four pairs of marks ( Fig. 25 , a–g), some individuals showed failures in the pair marks formation.

Antennae. Scape and pedicel marks varying in the shape and pigmentation marks ( Fig. 27 ).

Phallic sclerites ( Figs 28–38 ). Pseudepiphallic main lobe slightly inflated with V-median indentation; pseudepiphallic apodemes present; rami prolonged laterally, and fused posteriorly; lateral endophallic sclerite posteriorly bilobed, anteriorly bifurcated, with outer branch truncated ( Figs 29, 30, 37, 38 , arrow); ectophallic sclerite posteriorly V-bifurcate with inner branches forming an ectophallic fold, and outer placed between endophallic lobes.

Male and Female body Measurements. Tab. 1 .

Right Tegmen Measurements. Dorsal field length 7.8mm ±0.33 (7.1–8.7, n=47); dorsal field width 3.6mm ±0.17 (3.3–4, n=47); lateral field acessory veins 11.2±0.97 veins (9–13, n=36); mirror area 10.1mm ²±0.93 (8.2–12.2, n=47); harp area 4.3mm ²±0.39 (3.2–5 n=41); file length 1.1mm ±0.06 (0.8–2.6, n=50); file teeth number 46±3.64 (39–49, n=45). The table 2 presents right tegmen measurements comparing the four groups of O. pictus n. sp. We carried out a Principal Component Analysis comparing of the tegmen measurements in the four groups deffined by the body colour of specimens, and no differences were seen (component one 90.7%, and component two 7.6%) ( Fig. 39 ).

Structure/Groups 1, n=12 2, n=12 3, n=11 4, n=6 Average Metanotal Gland Measurements (n=86). Metanotal gland length, 1.2mm ±0.07 (1.1–1.4); metanotal gland width, 1.5mm ±0,08 (1.2–1.7); cavity area 0.57mm ²±0,15 (0.45–0.65); scutum area 1.1mm ²±0.08 (0.9–1.3mm ²); scutellum area 0.42mm ²±0.04 (0.31–0.52); scutum length 0.88mm ±0.06 (0.76–1.11); scutum width 1.5mm ±0.08 (1.2–1.7); scutellum length 0.36mm ±0.03 (0.28–0.45); scutellum width 1.3mm ±0.06 (1.1–1.5). The table 3 presents metanotal gland measurements comparing the four groups of O. pictus n. sp. The comparison of the tegmen measurements shows no difference in the four groups (Principal Component Analysis: component one 68.8%, and componente two 19.7%) ( Fig. 40 ).

Calling song ( Figs 18–19 ). Individuals recorded: Group 1: R04 and R05; Group 2: SP04, GG06, GG10, GG11, GG12, R01, R11, R13, R18, R21, R25, R29, W02, W07, W08, W11, W12 and W14; Group 3: GG05, GG07, GG09, R06, R09, R12, R15, R17, R19, R20, R22, R26, W01, W03, W04, W06, W09 and W10; Group 4: SP06, GG14, R08 and R14. There were significant positive effect of temperature on pulse rate (F1,39=717.58, p<0.001, R²=0.95), and of pulse rate on dominant frequency (F1,39=627.88, p<0.001, R²=0.94). For both models we did not detect any difference of pulse rate and dominant frequency between groups (pulse rate x temperature: F3,36=2.32, p = 0.07; dominant frequency x pulse rate: F3,36=0.16; p=0.92).

Female ( Figs 41–49 ). Body color and dotts pattern similar to males; supranal and subgenital plates as Figures 48 and 49 , respectively; ovipositor apex denticulated ( Figs 42–47 ); Measurements, Tab. 1 .

Habitat. Same as O. lineolatus and O. pallidus ( Zefa et al. 2012) .

Figures

FIGURE 27. Oecanthus pictus n. sp. Variation found in scape and pedicel marks, in ventral view. Conventions: a—pedicel; b—scape.

FIGURES 5 – 12. Oecanthus pictus n. sp. holotype male. 5 — habitus in lateral view; 6 — habitus in dorsal view; 7 — stridulatory file; 8 — head and pronotum, dorsal view; 9 — Metanotal gland; 10 — right tegmen; 11 — subgenital plate; 12 — supranal plate.

FIGURES 13 – 14. Metanotal gland of Oecanthus pictus n. sp paratype. 13 — whole gland, dorsal view; 14 — posterior median lobe. Conventions: Sc—scutum; St—scutellum; ss—scutoscutellar suture; pml—posterior median lobe; a—tuft of bristles projected medio-anteriorly; b—bristles projected medio-posteriorly; c—bristles projected dorso-posteriorly.

FIGURES 15 – 19. Calling songs of Oecanthus pictus n. sp. 15 — Holotype spectrogram; 16 — oscillogram of two pulses; 17 — oscillogram of the trill; 18 — regression lines showing the effect of temperature on pulse rate; 19 — relationship between dominant frequency and pulse rate.

FIGURES 1 – 4. Male habitus of Oecanthus pictus n. sp. paratypes representing the groups according color pattern. 1 — Male of the group 1. 2 — Male of the group 2. 3 — Male of the group 3. 4 — Male of the group 4.

FIGURES 20 – 25. Head, pronotum and legs of Oecanthus pictus n. sp. paratypes. 20, 21, 22 — head and pronotum, lateral view, increasing pigmentation; 23 — legs I and II, respectively, lateral view, inner and outer faces; 24 — legs III, lateral view; 25 — Tibia III, lateral view. Conventions: L—left leg outer side; R—right leg inner side; a, c—set of three marks; b—ring; d – gpairs of marks.

FIGURES 28 – 38. Male genitalia of Oecanthus pictus n. sp. 28 — ventral view with membranes; 29 — phallic sclerites, dorsal view; 30 — phallic sclerites, ventral view; 31 — main lobe of pseudepiphallus, dosal view; 32 — pseudepiphallus, ventral view; 33 — pseudepiphallus, dorsal view; 34 — phallic sclerites, diagonal view; 35 — pseudepiphallus, diagonal view; 36 — ectophallic sclerite; 37 — ectophallic and endophallic sclerites; 38 — endophallic sclerite. Conventions: MLPs—main lobe of pseudepiphallus; 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; Ec—endophallic cavity; R – rami.

FIGURES 39 – 40. Comparison of the metanotal glands and tegmina by Principal Component Analysis (PCA) using linear variables. 39 — Metanotal gland; 40 — Tegmina. Group 1, red; Group 2, green; Group 3, blue; Group 4, yellow.

FIGURES 41 – 49. Oecanthus pictus n. sp. female. 41 — habitus; 42, 44, 46 — cerci and ovipositor, lateral, dorsal and ventral views, respectively; 43, 45, 47 — ovipositor apex, lateral, dorsal and ventral views, respectively; 48 — supranal plate; 49 – subgenital plate.

Tables

TABLE 1. Oecanthus pictus n. sp. Male and female measurements (mm).

Structure	Male	Female (n=10)
body length	10.2±0.66 (9–11.5, n=40)	11±0.6 (10–11.6)
pronoto length	1.6±0.12 (1.4–1.8, n=64)	1.7±0.06 (1.6–1.8)
pronoto width	1.7±0.12 (1.5–2, n=63)	1.7±0.06 (1.6–1.8)
head width	1.4±0.06 (1.2–1.5, n=65)	1.5±0.05 (1.4–1.5)
interocular distance	0.57±0.07 (0.48–0.71, n=66)	0.59±0.03 (0.53–0.62)
femur III length	5.5±0.29 (5–6, n=64)	4.2±0.23 (4–4.4)
tibia III length	6.1±0.29 (5.5–6.6, n=61)	5.7±0.34 (5.3–6.7)
ovipositor length	-	4.2±0.14 (4–4.4)