Pliacanthopus (Malayamantis) tricolor Wu and Liu, 2022

Wu, Chao & Liu, Chun-Xiang, 2022, New and little-known species of genus Pliacanthopus Giglio-Tos (Dictyoptera: Mantodea: Nanomantidae), Journal of Natural History (J. Nat. Hist.) 56 (29 - 32), pp. 1279-1296 : 1292-1295

Pliacanthopus (Malayamantis) tricolor Wu and Liu sp. nov.

( Figures 1 (c), 2(b), 3(d), 4(d), 5(e), 6(d), 9(d), 11(c), 12)

Material examined

3♀. Holotype: China: 1♀; Tibet, Medog, Beibeng ; 29.238°N, 95.173°E; 900 m; 11 August 2011; Wen-Xuan Bi leg . ( IZCAS). Paratypes: China: 1♀; Tibet, Medog, Gelin ; 29.227°N, 95.168°E; 1500 m; 22 August 2020; Yu-Chen Zheng leg . ( IZCAS). 1♀; same as above ( CWC) .

Description of female

Generally yellowish green with rich colours. Body slender, small-sized.

Head. Triangular. Compound eyes exophthalmic, with rounded margins. Ocelli ovoid, lateral ocelli similar to median ocellus. Juxtaocular bulges present, rounded, with a black spot ( Figure 2 (b)), the vertex with a low tubercle. Lower frons transverse, narrow; dorsal margin with concavity on each side, bulging on median part, without median tubercle, with black tear-shaped spots on both ends ( Figure 4 (d)). Antennae slender, filamentous, shorter than the body.

Pronotum. Relatively broad, with a median keel; supracoxal dilatation well marked, prozona with a pair of long black spots on anterior margin ( Figure 2 (b)). The ratio of pronotum length to supracoxal dilatation width about 2.68–2.70.

Prothoracic legs. Coxae slightly longer than pronotum, with smooth dorsal margin. Femora longer than coxae, dorsal margin slightly sinuate, with a series of denticles on external ventral margin; with 3 discoidal spines, 4 postero-ventral spines, and a genicular spur. Femora with 14–15 antero-ventral spines, spination pattern of which is IiiIiIiIiIiIiIi or IiIiIiIiIiIiIi. Tibiae interlaced with 7 long and short postero-ventral spines, spination pattern of which is I_IiiIiI (the two large basal spines far apart). Tibiae with 13– 14 antero-ventral spines gradually lengthening distad ( Figure 5 (e)). Tarsus nearly as long as tibia; the first joint of tarsus longer than total length of the remaining segments.

Meso- and metathoracic legs. Slender. First joint of mid tarsus as long as total length of the remaining segments; first joint of hind tarsus much longer than total length of the remaining segments. Ventral margins of claw of tarsus dentate, comb-like.

Wings. Fore wings surpassing abdomen, with rounded apex; fore wings hyaline, except for costal field; costal field opaque, gradually tapering towards apex, with black neighbouring medial veins; discoidal field iridescent, with large, approximately quadrilateral cells; stigma nearly missing ( Figure 6 (d)). Hind wings longer than fore wings, iridescent, hyaline except costal field apex.

Abdomen. Tubular. Supra-anal plate triangular. Cerci elongate; last segment distinctly elongate, sheet-like, lanceolate, with subacute apex ( Figure 9 (d)).

Colouration

Overall yellowish green ( Figure 1 (c)). Head pale green. Compound eyes yellow, with reddish spots and markings along antero-lateral margin. Lower frons dark green, except a black spot at each end. Juxtaocular bulges with a black spot. Antennae pale green near base, other segments with blackish-brown apex. Pronotum pale green; median keel yellow, with a yellowish-white area on each side. Legs yellowish green; irregular greenish bands present on prothoracic legs; tip of spines brownish. Fore wings light green to white; costal field bright yellow, opaque; discoidal field hyaline, medial veins and cross-veins adjacent to costal field black, the rest of the veins pale green ( Figure 6 (d)). Hind wings hyaline except the distal part of the costal field, veins pale green, except yellow costal field apex. Abdomen and cerci yellow-green, whitish.

Male

Unknown.

Measurements (length in mm, holotype in parentheses), female.

Body (head to abdomen end): 26.85–27.08 (27.08); body (head to wings): 29.44–29.94 (29.94); pronotum: 5.46–5.50 (5.50); fore femora: 5.83–5.90 (5.90); fore tibiae: 4.60–4.64 (4.64); hind femora: 6.85–6.92 (6.92); hind tibiae: 7.58–7.63 (7.63); hind tarsus: 5.44–5.60 (5.60); fore wing: 18.85–18.98 (18.98); hind wing: 19.65–20.20 (20.20).

Differential diagnosis

Although differences from Pliacanthopus (Malayamantis) malayanus are unclear, P. (M.) flavus has a rounded last cercal segment, vs. P. (M.) visayanus , P. (M.) bimaculatus and P. (M.) tricolor sp. nov. with very elongate, subscute cercal segments, but the widest part is near the base in P. visayanus , while it is just after the first third in the Chinese species. This new species is slightly similar to Pliacanthopus (Malayamantis) bimaculatus ( Wang, 1993) . It can be distinguished from the congeners by the following characteristics of females: (1) body size is larger; (2) lower frons is dark green, with a black spot on each end ( Figure 4 (d)); (3) pronotum bears a pair of long black spots on the front margin ( Figure 2 (b)); (4) spination pattern is different in the fore tibial postero-ventral spines; (5) fore wings possess a black radial vein ( Figure 6 (d)). In addition, its geographical distribution is also different.

Distribution

China: Tibet, Medog.

Etymology

The new species was named after the rich colours it displays when alive.

Discussion

Female characters of P. (M.) tricolor sp. nov. are unique enough to be easily distinguished from all other known congeners, although no male specimens were available for genital dissection. The two Chinese species are distantly isolated; P. (M.) bimaculatus ( Wang, 1993) is distributed in southern Yunnan, while P. (M.) tricolor sp. nov. is distributed on the southern slopes of the Himalayas ( Figure 12 ). Pliacanthopus (M.) tricolor sp. nov. is the westernmost and northernmost record of the genus, appearing in the Himalayas up to 1500 m elevation; the other species are distributed in the tropical rainforest environment of Southeast Asia. In Tibet, we only collected three female specimens of P. (M.) tricolor sp. nov., which were attracted by a light trap, from June to September during 10 expeditions from 2011 to 2020. Males could not be found. We expect further study on this unique species in the future.

Key to species of Pliacanthopus Giglio-Tos, 1927

1. Anterior tibiae with about 25 postero-ventral spines (subgenus Pliacanthopus ) ............. .................................................................................................................................... P. (P.) mantispoides

- Anterior tibiae with about 7–13 postero-ventral spines (subgenus Malayama ntis) ............................................................................................................................................................ 2

2. Juxtaocular bulges each with a black spot.................................................................................. 3

- Juxtaocular bulges without black spot ......................................................................................... 4

3. Medial veins and cross-veins adjacent to costal field of fore wings black .......................... ............................................................................................................................ P. (M.) tricolor sp. nov.

- Medial veins and cross-veins adjacent to costal field of fore wings pale green ............... ................................................................................................................................... P. (M.) bimaculatus

4. Anterior tibiae with about 10 postero-ventral spines............................. P. (M.) malayanus

- Anterior tibiae with 12–13 postero-ventral spines................................................................... 5

5. Last segment of the cerci with rounded apex.......................... .......................... P. (M.) flavus

- Last segment of the cerci with subacute apex...................... ...................... P. (M.) visayanus

Figures

Figure 1. Adult of Pliacanthopus spp. in natural habitat. (a) P. (M.) flavus, male; (b) P. (M.) bimaculatus, male; (c) P. (M.) tricolor sp. nov., female, photograph © Wen-Xuan Bi, published with permission.

Figure 2. Head and pronotum of Pliacanthopus spp., dorsal view. (a) P. (M.) bimaculatus, male; (b) P. (M.) tricolor sp. nov., female, photograph © Wen-Xuan Bi, published with permission.

Figure 4. Head of Pliacanthopus spp., anterior view. (a) P. (M.) flavus; (b, c) P. (M.) bimaculatus; (d) P. (M.) tricolor sp. nov.; (a, b) male; (c, d) female. Abbreviations: ey, compound eye; lf, lower frons; oc, ocellus.

Figure 5. Fore tibiae of Pliacanthopus spp., dorsal view. (a) P. (M.) flavus; (b–d) P. (M.) bimaculatus; (e) P. (M.) tricolor sp. nov.; (a–c) male; (d, e) female. Abbreviations: pvts, posteroventral tibial spines.

Figure 6. Fore wings of Pliacanthopus spp., dorsal view. (a) P. (M.) flavus, male; (b) P. (M.) bimaculatus, male; (c) P. (M.) bimaculatus, female; (d) P. (M.) tricolor sp. nov., female.

Figure 9. Male external genitalia, cercus and claw of Pliacanthopus spp. (a–c, e) P. (M.) bimaculatus; (d) P. (M.) tricolor sp. nov.; (a) male external genitalia; (b–d) cercus; (e) claw of prothoracic leg tarsus. Abbreviations: afa, phalloid apophysis; bl, basal lobe of ventral phallomere; paa, posterior process of left phallomere; pda, primary distal process; sdpl, lateral secondary distal process.

Figure 12. Distribution map of Pliacanthopus spp. in Asia. (Δ) P. (P.) mantispoides; (▲) P. (M.) flavus; (●) P. (M.) malayanus; () ◆P. (M.) bimaculatus; (▀) P. (M.) visayanus; () ★P. (M.) tricolor sp. nov.