Stephoblemmus minor (Shiraki, 1911) Zheng & Gu & He & Huang & Ma, 2023

Zheng, Yan-Na, Gu, Jun-Jie, He, Zhu-Qing, Huang, Huateng & Ma, Li-Bin, 2023, On a taxonomic feature that has been overestimated in classification practice: an integrative taxonomic revision of Stephoblemmus Saussure, 1877 based on morphology and molecular phylogeny (Orthoptera: Grylloidea; Gryllidae; Gryllinae), Arthropod Systematics & amp; Phylogeny 81, pp. 761-779 : 761

Stephoblemmus minor (Shiraki, 1911) comb. n.

Figures 2 , 3 , 8, S1-S3, S5M, N

Gryllus minor Shiraki, 1911: 54; 1930: 211; Wu: 1929; 25; Hsu. 1929:37; 1931: 30

Gryllulus minor Chopard, 1936:5; Hisumatsu, 1952: 43; synonymized by Roberts, 1941: 33

Modicogryllus minor Chopard, 1961: 274; Randell, 1964: 1586

Mitius minor Yin & Liu, 1995: 59; Ichikawa, Murai & Honda, 2000: 263; Storozhenko & Paik, 2007, 97; Storozhenko, Kim & Jeon, 2015: 118

Gryllus splendens (= M. splendens ) Shiraki, 1930: 215; Yang & Yang, 1995: 5, syn. n.

Gryllodes blennus (= M. blennus ) Saussure, 1877: 383; Yang & Yang, 1995: 2, misidentification

Chinese name.

小素蟋

Examined materials.

CHINA- Henan Prov. • 2 ♂. Liankangshan , Xin Country , 31°64.1′N, 114°79.4′W, on grass, Sep. 4-8, 2014, Ma, Libin coll. (SNNU); Hubei Prov. • 5 ♂, Wuhan City, 30°62.1′N, 114°13.3′W, on grass, Sep. 1, 2018, Xie, Lingde coll. (SNNU) .

Measurements (mm).

♂ (n = 6): BL 10.30 ± 1.05, HL 1.96 ± 0.12, HW 2.86 ± 0.76, PL 2.12 ± 0.14, PW 2.96 ± 0.09, FWL 4.37 ± 0.32, HTL 3.57 ± 0.75.

Emended diagnosis.

Male: Frons round. Tegmina reaching the middle of the ninth abdominal tergum. Apical field armed with irregular cells. Apical margin of epiphallic middle lobe arc-like. Apical margin of epiphallic lateral lobes truncated or arc-like; ventrally viewed, the distal of epiphallic lateral lobes possessing two small protrusions or a truncate projection. Epiphallic lateral and middle lobes connected in a V-shaped.

Description.

Male: Postclypeus shaped like a narrow band; the anteclypeus shaped like a broad shield and slightly wider than the postclypeus. Labrum shield-like, apical margin slightly round. Tegmina reaching the middle of the ninth abdominal tergum. In tegmina dorsal field, bearing three chord veins, connecting to the proximal part of the mirror by two veins; diagonal vein proximally bifurcated, both branches connected to CuA vein; with two oblique veins; mirror shield-like; dividing vein absent; apical field armed with irregular cells. In the lateral dorsal field, five branches of the subcostal vein. Outer tympanum about three times more than the inner. Hind tibiae armed with dorsal spurs which almost equal in length, five inner dorsal spurs and six outer ones; outer apical spurs three (this dorsal apical spur about 3/2 length of the dorsal spurs, middle one slightly shorter than the dorsal and ventral one almost equal in length of the dorsal spurs) and inner two (equal in length and slightly longer than the dorsal spurs).

Genitalia.

Epiphallic middle lobe about 1/3 length of the epiphallic lateral lobe and armed with an apical margin arc-like. Epiphallic lateral lobes sheet-like, in dorsal view, apical margin of epiphallic lateral lobes truncated (Fig. 9G ) or arc-like (Fig. 9H ); ventrally viewed, distal of epiphallic lateral lobes possessing two small protrusions (Fig. 9K-M ) or a truncate projection (Fig. 9N ). Epiphallic lateral and middle lobes connected in V-shaped (Fig. 9D ). Ectoparamere stripe-like, distally enlarged.

Female.

Unknown.

Coloration.

Body dark brown. Maxillary palpi and labial palpi yellowish. Legs yellow-brown.

Remarks.

This species was first reported in Japan and subsequently recorded in China (Taiwan, Shanghai, Zhejiang, Jiangsu, etc.) (Shiraki, 1930; Yin & Liu, 1995). There is an intraspecific variation of male genitalia in this species, and both the original and the later literature provide less and almost useless information on the feature of genitalia. This situation may end up making some taxonomic problems, such as the Chinese species of M. blennus and M. splendens . Yang & Yang (1995) reported them in Taiwan Province and only pointed out that they slightly differ in S. minor comb. n. in body size and some detailed features of male genitalia. In our study, S. minor comb. n., an intraspecific varied species possesses all characteristics of M. blennus (Fig. 8F and I ) and M. splendens (Fig. 8E, H and L ) as described and illustrated by Yang & Yang (1995). The details of these features of S. minor comb. n. as (1) body size is varied from 9.48-11.12 mm; (2) apical margin of epiphallic lateral lobes are truncated (Fig. 8E ) or arc-like (Fig. 8F ) in dorsal view; (3) distal of epiphallic lateral lobes possesses two small protrusions (Fig. 8I-K ) or a truncate projection (Fig. 8L ) in ventral view. Furthermore, based on the phylogenetic relationship (Fig. 3 ), all samples from China (including the sample of M. splendens collected in Taiwan), Thailand and Japan are closely related and clustered into a single lineage. Therefore, Chinese M. blennus should be a misidentification of S. minor comb. n. and M. splendens should be a synonym of S. minor comb. n.

Figures

Figure 2. Time-calibrated phylogeny inferred using BEAST. Posterior probability (PP) values are indicated by node color. Node numbers next to nodes represent the divergent times. Purple bars indicate 95 % credibility intervals of estimated node ages. The left in Roman numbers represents fossil calibration points. The primary species of study for this article are shaded red, including species of Loxoblemmus, Mitius, and Stephoblemmus. The blue letter is the type species of Stephoblemmus. The geological timescale is shown at the bottom (Ma = million years ago).

Figure 3. The maximum-likelihood (ML) tree for 30 samples of Mitius and Stephoblemmus using the concatenated COX 1 + 18 S + 28 S data set, and the species delimitation results. Posterior probabilities from MRBAYS (left) and bootstrap supports from IQTREE (right) are indicated for all nodes. Clade nodes are marked in red to indicate the morphology of the male's head.

Figure 8. A body of S. minor comb. n., scale bar: 5 mm; B - L Genitalia of S. minor comb. n., scale bar of chart B-F, I-L: 0.5 mm, scale bar of chart G-H: 0.25 mm (B - dorsal view; C - lateral view; D - ventral view; E-F - dorsal enlarged view; G - caudal view; H - anterodosolateral view; I-L - apex of a lateral enlarged view). Notes: E - epiphallic lateral lobes apical margin truncated; F - epiphallic lateral lobes apical margin arc-like; I-J - distal of epiphallic lateral lobes possessing two small protrusions; L - distal of epiphallic lateral lobes possessing a truncate projection. Of these, C, G, and I are the same as that of M. blennus in Taiwan; E, H, and J are the same as that of M. splendens (Yang & Yang, 1995 )).

Figure 9. A - B Female body, scale bar: 5 mm; A - S. humbertiellus; B - S. enatus comb. n.; C - F ovipositor, scale bar: 0.5 mm, C - inside of ovipositor of S. humbertiellus; D - outside of ovipositor of S. humbertiellus; E - inside of ovipositor of S. enatus comb. n.; F - outside of ovipositor of S. enatus comb. n.