Mirigryllus nigrus He, 2020

He, Zhu-Qing, Shen, Chu-Ze, Wu, Xue, Chen, Lin & Li, Kai, 2020, Report of a new genus Mirigryllus belonging to tribe Modicogryllini, with a new species M. nigrus from Zhejiang, China (Orthoptera: Gryllidae: Gryllinae Modicogryllini), Zootaxa 4869 (1), pp. 112-120 : 115-119

Mirigryllus nigrus He sp. nov.

Holotype: 1 male, CHINA, Zhejiang, Lin’an, Qingliangfeng Mt. (N 30°06'39" E 118°54'01"), alt. 920m, 12-v-2018, coll. HE Zhu-Qing.

Paratypes: 3 males and 5 females, same data as holotype .

Description. Male. Body medium size with pubescence. Head: frontal rostrum 2 times as wide as the 1st antennal joint ( Fig. 3C, D ), vertex obviously flat, median ocellus flat, smaller than lateral ocelli and located lower than lateral ocelli ( Fig. 3C ), maxillary palpi with 3rd–5th joints long and 5th slightly widened ( Fig. 3C ); thorax: pubescent, disc of pronotum as wide as head ( Fig. 3A ), anterior and posterior margin almost straight, rounded borders between disc and lateral lobes, tympanum on outside long and big, but very small on inner side, forewing not longer than 2 times of pronotum, 2 oblique veins curved, without crossvein between chord and mirror, mirror longitudinal elongated with 2 curved dividing vein, apical field short ( Fig. 3A ). Legs strong, hind femur little longer than hind tibiae, 5 pairs of dorsal spines alternated on hind tibiae, 5 pairs of spines on basitarsomere ( Fig. 3E ), epiproct triangle with apical part in arc-shape ( Fig. 3F ). Genitalia: epiphallus transverse with posterior epiphallic lobes long and thin, without a medial lobe at posterior, ectoparameron transparent with basal part wide, as long as posterior epiphallic lobes ( Fig. 3H, I, J ).

Female. Similar to male including epiproct, veins on dorsal field of forewing not parallel, more or less crossed ( Fig. 3B ), ovipositor straight, without teeth on apical side ( Fig. 3G ).

Coloration. Nearly black. One white transverse bar connecting lateral ocelli, but separated with median ocellus, maxillary palpi white, two vertical yellow line on occiput, indistinct yellow stripes behind eyes, tarsi and spurs brown ( Fig. 2 G–J).

Variation. Macropterous form individuals appeared occasionally in lab cultures. Hindwing is two times as long as forewing ( Fig. 2G, H ).

Nymph. Hatchling: Head brown, body yellow and legs pale ( Fig. 2A ). Junior instar: Brown to black. Band between lateral ocelli appeared ( Fig. 2B ). Penultimate instar: Total black. Length of ovipositor in dorsal view as long as one abdominal segment ( Fig. 2C, D ). Ultimate instar: Total black. Length of ovipositor in dorsal view as long as 2–3 abdominal segments ( Fig. 2E, F ).

Etymology. Species name nigrus means its black body color.

Measurements (in mm). Male: body length 13.62–14.08, pronotum length 2.60–2.81, hind femur length 8.63–9.16, hind tibiae length 6.46–6.63, forewing length 4.66–4.90.

Female: body length 14.20–15.53, pronotum length 2.81–3.01, hind femur length 8.55–9.19, hind tibiae length 6.20–6.51, forewing length 4.77–6.99, ovipositor length 6.97–7.55.

Songs. The calling song was about 8.63 cycle/min. Each cycle contained 12–16 pulses in 0.165± 0.013s from weak to strong ( Fig. 4 ).

Life cycle. As we found many hatchlings in August, combined the adult appearance date, we infer that this species is univoltine with adult appeared from May to July and nymphs overwinter.

Figures

FIGURE 2. Mirigryllus nigrus sp. nov. in living condition.A, hatchling; B, junior instar; C, D, penultimate instar; E, F, ultimate instar; G, male (macropterous); H, female (macropterous); I, male (brachypterous); J, female (brachypterous).

FIGURE 3. Features of Mirigryllus nigrus sp. nov. A, male pronotum and forewing; B, female pronotum and forewing; C, male head in front view; D, male head in dorsal view; E, male hind tibiae and basitarsomere in dorsal view; F, male epiproct in dorsal view; G, ovipositor in lateral view; H, male genitalia in dorsal view; I, male genitalia in ventral view; J, male genitalia in lateral view.

FIGURE 4. Calling song of Mirigryllus nigrus. Wave of songs with 1s and 0.1s scale bar.