Hygronemobius dialeucus Martins & Pereira

Martins, Luciano De P., Pereira, Marcelo R., Henriques, Augusto L. & Zefa, Edison, 2014, Two new species of Hygronemobius Hebard, 1913 (Orthoptera, Grylloidea, Nemobiinae) from Brazilian Amazon, Zootaxa 3794 (3), pp. 469-480 : 476-479

Hygronemobius dialeucus Martins & Pereira , sp. nov.

( Figs. 1 C–D; 3D–F; 4B; 5)

Etymology. The specific name refers to the white markings on the pronotum, abdomen and legs (from Greek dialeukos = marked with white).

Diagnosis. (i) Head brown without white marks ( Figs. 1 C–D, 5A); (ii) pronotum black with white marks on the dorsal disc: anterior margin, a pair of dots; posterior margin, in female, a stripe slightly incurved on the lateral lobes ( Fig. 1 D), in male, three dots, the lateral ones bigger ( Figs. 1 C, 5A); (iii) femora I and II with an elongated white dot dorsally ( Figs. 1 C–D, 5A); (iv) tibia III with an elongated white dot above the last inner dorsal spur ( Fig. 1 C–D); (v) femur III with two white dots on the inner face, the distal bigger than the proximal ( Figs. 1 C–D, 5A); (vi) first tarsomeres of legs I, II and III with a dorsal elongated white spot ( Fig. 1 C–D); (vii) tergite IV of females with a transversal white band ( Fig. 1 D); (viii) terminal tergites with a white band or two spots, comprising laterodistal portion of tegite IX, basal portion of supranal plate and cerci adjacent area ( Figs. 1 C–D, 5A, E, G); (ix) pseudepiphallic sclerite sub-trapezoidal, posterior margin twice wider than the anterior margin ( Fig. 3 E); (x) pseudepiphallic apical lobes longer than half length of pseudepiphallic sclerite ( Fig. 3 E); (xi) infero-posterior angle of pseudepiphallic sclerite rounded, in lateral view ( Fig. 3 F); (xii) setae present only on pseudepiphallic apical lobes.

Description. Holotype, male, measurements (mm): body length, 6.0; pronotum length, 1.3; pronotum width, 2.0; head width, 2.0; length of femur III, 4.1; length of tibia III, 3.2; right tegmen length, 2.8; right tegmen width (dorsal field), 3.2. General color of the body black with some white markings. Head brown, except: vertex dark brown but the adjacent area to eyes light brown; occiput light brown; gena light brown; black eyes; scape e pedicel light brown; flagellum with the firsts antennomeres light brown becoming darker towards the apex; frons with an inverted dark brown T-shaped spot; clypeus, lateral portion of the postclypeus dark brown and center-basal portion of the anteclypeus whitish; labrum light brown, basal portion dark brown with a whitish stripe at the apex; Maxilla light brown, lacinia with whitish apex; maxillary palp: first two palpomere dark brown; third palpomere whitish with proximal portion dark brown; fourth palpomere whitish; fifth palpomere dark brown with whitish apex and third proximal portion light yellow; labial palp: first palpomere dark brown; second palpomere dark brown on proximal half and whitish on distal half; third palpomere from whitish to dark brown with apex whitish. Thorax, pronotum black with five white marks on the dorsal disc ( Fig. 5 A): anterior margin, a pair of dots; posterior margin, three dots, the lateral ones bigger; lateral lobe evenly black ( Fig. 5 C); pronotum with black fine pubescence and strong bristles covering all its extension. Dorsal field of right tegmen dark brown with light yellow spots ( Fig. 5 D) situated: 1) close to insertion of tegmen on metanotum; 2) on junction of anal veins; 3) distal portion of cordal area; 4) continuous band between Cu1 and M veins until external portion of apical area; 5) large spot between longitudinal vein in harp and Cu1. Lateral field of right tegmen with five veins; color pattern: a long dark yellow band between R vein and superior vein of lateral field; proximal and supero-distal portions dark brown, remaining areas lighter. Hindwings absent. Prosternum dark brown. Mesosternum dark brown with posterior third light brown. Metasternum dark brown. Legs I and II with similar pattern: coxae and trochanteres dark brown; femora dark brown to black with an elongated white dot on dorsal face ( Fig. 5 A); tibiae dark brown, tibia I with an oval tympanum on outer face; tarsi dark brown, first tarsomere with a dorsal elongated white spot. Leg III: coxa and trochanter dark brown; femur III black, knee and proximal area of lighter color, two white dots on the inner face, the distal bigger than the proximal ( Fig. 5 A); tibia III black with an elongated white spot close the last inner dorsal spur ( Fig. 5 A); tarsus III dark brown, first tarsomere with a dorsal elongated white spot. Abdomen, tergites black; a continuous band comprising latero-distal portion of tegite IX, proximal half of supranal plate and cerci adjacent area ( Fig. 5 A); supranal plate with apex rounded ( Fig. 5 E); sternites I–IV dark brown, sternites V–VII dark brown in central portion and black in laterals, sternite VIII evenly black ( Fig. 5 B); subgenital plate black with distal and lateral margins rounded; cerci light brown. Male genitalia ( Fig. 3 D–F): pseudepiphallic sclerite sub-trapezoidal, distal margin twice wider than the proximal margin; pseudepiphallic apical lobes well developed, longer than half length of pseudepiphallic sclerite; numerous smalls setae presents only on pseudepiphallic apical lobes; pseudepiphallic median lobes with distal margin rounded, visible in lateral view; ectophallic fold large, as long as pseudepiphallic sclerite, and as high as pseudepiphallic median lobes (in lateral view, Fig. 3 F); ectophallic apodeme crossing and surpassing rami ( Fig. 3 E); endophallus divided in three sclerites, the lateral sclerites triangular and larger than the central one ( Fig. 3 D–E).

Observations in paratypes. Stridulatory file of right tegmen with 80–95 teeth (n=5). White band on terminal tergites not continuous forming two spots separated by a narrow black stripe ( Fig. 1 C). Female, body shape and color pattern similar to Holotype, except: tegmina reduced to black lateral scales ( Fig. 1 D); posterior margin of pronotum with a wide white stripe slightly incurved on lateral lobes ( Fig. 1 D); tergite IV with a wide transversal white band ( Fig. 1 D); supranal plate dark brown ( Fig. 5 G); subgenital plate from dark to light brown, sub-rounded with a central invagination on apex ( Fig. 5 H); all sternites dark brown; prosternum dark brown; mesosternum dark brown with posterior half light brown; metasternum dark brown; ovipositor, valves dark brown, proximal two-thirds of ventral valves light brown ( Fig. 5 I); apex of the dorsal valves slightly denticulate on their margins ( Fig. 5 I).

Calling song (25.5–28°C, Tab. 0 1, Fig. 4 B): 5 pulses per chirp, rarely chirps with 4 pulses; chirp duration with 5 pulses of 91 ± 7 ms (83–99, n=40); inter-chirp interval of 272 ± 29 ms (220–330, n=40); chirp rate of 160 ± 15,67 chirps/min (140–176, n=4); pulse duration of 8.13 ± 0.43 ms (7–9, n=30); dominant frequency of 7.3 ± 0.39 kHz (6.8–7.7, n=4).

Habitat and male calling site. Males and females live in litter and were collected only inside the forest. Males were seen stridulating on soil under dry leaves during daytime.

Comments. Hygronemobius dialeucus sp. nov. belongs to the amoenus group proposed by Desutter- Grandcolas (1993). The male genitalia of Hygronemobius dialeucus sp. nov. is more similar to that of H. amoenus differing by: pseudepiphallic apical lobes apex longer and thinner ( Fig. 3 D–E); infero-posterior angle of pseudepiphallic sclerite rounded ( Fig. 3 F). Among species of amoenus group, position and shape of white spots are very important to determining the species, wherefore H. torquatus differs from H. dialeucus sp. nov. by having: dorsal disc of pronotum with a large transversal white stripe near its anterior margin and posterior margin without white markings; only a white dot on femur III; in females, tergites II–III with two pairs of lateral white dots and tergite IV black; H. albolineatus differs from H. dialeucus sp. nov. by having: two longitudinal white stripes running dorsally from fastigium to the posterior margin of pronotum, and in females reaching the tergite IX; a whitish dot behind the eyes; palpi without white markings; tibiae and tarsi without white dots; central portion of posterior margin of pronotum black; tegmina apex whitish. H. boreus differs from H. dialeucus sp. nov. by having: two longitudinal white stripes running dorsally from fastigium to the posterior margin of pronotum; central portion of posterior margin of pronotum black; in females, tergite II with a transversal white stripe, tergite III with white spots on lateral margins and tergite IV with central portion black; tibiae and tarsi without white dots. H. amoenus differs from H. dialeucus sp. nov. by having: head with two longitudinal thin white stripes, from fastigium to occiput; and two longitudinal white stripes along lateral margins of dorsal disc of pronotum. Calling song of H. amoenus , H. albolineatus and H. dialeucus sp. nov. are characterized by brief chirps with 3 pulses in H. amoenus , usually 4 pulses in H. albolineatus ( Desutter-Grandcolas 1993) and usually 5 pulses in H. dialeucus sp. nov. ( Fig. 4 B).

Measurements (mm). Male (n=10, excluding holotype). body length, 6.18 ± 0.43 (5.50–6.80); pronotum length, 1.28 ± 0.11 (1.20–1.50); pronotum width, 1.91 ± 0.06 (1.80–2.00); head width, 1.93 ± 0.05 (1.90–2.00); length of femur III, 3.78 ± 0.20 (3.50–4.10); length of tibia III, 3.12 ± 0.14 (2.90–3.30); right tegmen length, 2.95 ± 0.16 (2.70–3.20); right tegmen width (dorsal field), 2.42 ± 0.04 (2.40–2.50). Female (n=5): body length, 5.98 ± 0.41 (5.40–6.30); pronotum length, 1.42 ± 0.08 (1.30–1.50); pronotum width, 1.86 ± 0.05 (1.80–1.90); head width, 2.00 ± 0.10 (1.90–2.10); length of femur III, 4.08 ± 0.18 (3.90–4.30); length of tibia III, 3.36 ± 0.18 (3.10–3.60); ovipositor length, 2.60 ± 0.07 (2.50–2.70).

Type material. Holotype ♂: BRASIL, AM[azonas], Manaus, R.[eserva] F.[lorestal] Adolpho Ducke, AM-010, 26-31.viii.2011, 02º55’49”S, 59°58’31”W. Coleta ativa. L. P. Martins & V. Linard / 127PROSET ( INPA). Holotype condition: detached left leg III; genitalia placed in microvial with glycerin; all parts are maintained in holotype's tube. Paratypes: same data of Holotype (1♂, 1♀, INPA). idem 23-28.ix.2011 / 144PROSET (1♂, INPA). idem 26- 31.i.2012. L. P. Martins & K. Soares (2♂, MZUSP). idem 14-19.x.2011. L. P. Martins & A. Souza / 152PROSET (1♂, INPA). idem / 153PROSET (1♂, INPA). idem / 154PROSET (1♂, INPA). idem (3♂, 3♀, INPA). idem 21- 24.iv.2011. L. P. Martins (1♀, INPA). idem 01-15.vii.2011 (2♂, 1♀, INPA). idem 23-28.ix.2011. L. P. Martins & V. Linard (2♀, MZUSP). idem 01-03.xi.2010. L. P. Martins & D. Mendes (1♂, INPA). idem / 05PROSET (1♂, INPA). idem 26-28.ii.2011 / 49PROSET (1♂, INPA). idem (1♀, INPA). idem 15-19.xi.2013. L. P. Martins & L. G. Da Silva (3♂, INPA).

Figures

FIGURE 1. Paratypes habitus. A – B— Hygronemobius duckensis sp. nov.: A—male; B—female. C – D— Hygronemobius dialeucus sp. nov.: C—male; D—female.

FIGURE 3. Male genitalia of holotypes. A – C— Hygronemobius duckensis sp. nov.: A—ventral view; B—dorsal view; C—lateral view. D – F— Hygronemobius dialeucus sp. nov.: D—ventral view; E—dorsal view; F—lateral view. Abbreviations: Ps. A. L—pseudepiphallic apical lobe; Ps. M. L—pseudepiphallic median lobe; Ps. P—pseudepiphallic parameres; Ps. Sc—pseudepiphallic sclerite; End. Cv—endophallic cavity; Ect. F—ectophallic fold; Ect. Ap—ectophallic apodeme; End. Sc—endophallic sclerite; End. Ap—endophallic apodeme.

FIGURE 4. Calling song spectrograms. A—three chirps of Hygronemobius duckensis sp. nov., the first with 20 pulses and the other ones with 21 pulses; B—nine chirps of Hygronemobius dialeucus sp. nov., first eight with five pulses and the last one with four pulses.

FIGURE 5. Hygronemobius dialeucus sp. nov. A—male holotype, in dorsal view; B—male holotype, in ventral view; C—lateral view of pronotum, paratype; D—right tegmina dorsal field, paratype; E—supranal plate of holotype; F—subgenital plate of holotype; G – I—female paratype: G—supranal plate; H—subgenital plate; I—lateral view of ovipositor.