Phaesticus mellerborgi ( Stål, 1855 )

Zha, Ling-Sheng, Skejo, Josip, Mao, Ben-Yong & Ding, Jian-Hua, 2021, Taxonomic revision of Phaesticus Uvarov and synonymy with Flatocerus Liang & Zheng syn. nov. (Orthoptera: Tetrigidae), Zootaxa 4965 (3), pp. 501-514 : 504-505

Phaesticus mellerborgi ( Stål, 1855)

Figs. 2 , 3

( Tettix mellerborgi Stål, 1855 ; Phaestus mellerborgi ( Stål, 1855) ; Lamprauges mellerborgi ( Stål, 1855))

= Phaesticus insularis ( Hancock, 1907) syn. nov. ( Phaestus insularis Hancock, 1907 ; Lamprauges insularis ( Hancock, 1907))

= Phaesticus sumatrensis ( Willemse, 1928; synonymized by Günther (1938)) ( Phaestus sumatrensis Willemse, 1928 )

= Phaesticus carinatus Zheng, 1998 syn. nov.

= Phaesticus azemii Mahmood, Idris & Salmah, 2007 syn. nov.

= Flatocerus brachynotus Liang, Chen & Chen, 2008 syn. nov.

= Phaesticus uvarovi Storozhenko & Dawwrueng, 2015 syn. nov.

Material examined. One male (the brachypterous form, Fig. 3 ), Yunnan, Yingjiang (Jiemao), 1200 m, 31 July 2015, coll. Ji-Shan Xu; three females (the brachypterous form, Fig. 3 ) , PR China: Yunnan, Ruili , 23°55′N, 97°33′E, 791 m, 1 October 2019, coll. Miao Li; one female (the macropterous form) , PR China: Yunnan, Lüchun (Pinghe) (type locality of F. brachynotus , Fig. 2 ), 26 July 2006, coll. Ji-Shan Xu.

Notes. Liang et al. (2008) introduced F. brachynotus based on many specimens from Yunnan, PR China (seven males and nine females from Lüchun, one female from Puer). The species was described with the following characters: hind pronotal process varies from not reaching knees (some females) to nearly reaching apices of hind femora (males and some females); hind wings vary from not reaching (most females) to slightly surpassing apex of hind process (males and few females). Our collections from Yunnan exactly match the characters of F. brachynotus . Based on the original description and examined specimens, F. brachynotus could roughly be classified into two types: the macropterous form ( Fig. 2 ) and the brachypterous form ( Fig. 3 ). The latter differs from the former mainly by: 1) clearly shortened hind pronotal process and hind wings; and 2) relatively short antennae (5–5.5 mm, shorter than 6.5–7.3 mm of the macropterous form). Flatocerus brachynotus was described from many specimens and differences between its macropterous and brachypterous forms are distinct. The epithet ‘ brachynotus ’ explains the shortened pronotum of the brachypterous form. Taking these facts into account and the same locality of the collection (Yunnan), in order not to create taxonomic confusion, we accept the view of Liang et al. (2008) who treated the macropterous and brachypterous forms as a single species.

Phaesticus mellerborgi , P. carinatus , F. brachynotus , and P. uvarovi are morphologically very similar; their morphological differences include: 1) vertex slightly narrower, equal to, or slightly wider than eye (0.9–1.1 times, in females generally slightly wider than in males); 2) prozonal carinae and interhumeral carinae invisible, barely visible, or visible; 3) hind pronotal process elongated or shortened (varies from nearly reaching knees of hind femora to reaching the middle of hind tibiae, and in males generally longer than in females); 4) hind wings accordingly longer or shorter than the elongated or shortened hind process, respectively (reaching before or after the apex of hind pronotal process, respectively, and in males generally longer than in females); and 5) ventral margins of fore and mid femora straight or weakly undulated. In contrast, differences among these allied species are mainly related to the lengths of both hind pronotal process and hind wings ( Table 1 ). Geographically, P. mellerborgi , P. carinatus , and F. brachynotus have one shared locality (Yunnan, PR China), and P. uvarovi was recorded in Thailand, which is close to Yunnan. For these reasons, we combine these allied species into one species.

Phaesticus azemii was described only based on one male specimen from West Malaysia (Selangor), and the authors also recorded P. insularis at the same locality ( Mahmood et al., 2007). According to the original description and drawing, the type specimen of P. azemii is actually a nymph. Skejo (2017) clarified that the records from West Malaysia are all P. mellerborgi , and he considered P. azemii as a synonym of P. mellerborgi ; this suggestion was followed in the present study. In his report, the author determined all other records of P. insularis (Java, Sumatra and Malay Peninsula up to south of Thailand) as P. mellerborgi .

Phaesticus insularis is very similar to P. mellerborgi , as well. Hancock (1907) introduced the species to separate it from P. mellerborgi only by its more compressed antennae and narrower longitudinal furrow of the facial frontal costa, based on three females from northwestern Kalimantan (= Borneo), and Cigliano et al. (2021) provided online pictures of the specimens (syntypes). For comparison, the two morphological differences are both present within individuals of P. mellerborgi (e.g., Figs. 2 and 3 ), so it is not logical to separate them into two different species. To avoid unnecessary taxonomic confusion, we synonymized P. insularis with P. mellerborgi . Geographically, P. mellerborgi should have a wide distribution in Kalimantan ( Fig. 1 ); for example, Günther (1938) also recorded this species in the central part of the island.

Distribution ( Fig. 1 ). Java, Sumatra, Kalimantan, Singapore, West Malaysia, Thailand, India (Assam, Mizoram), and PR China (Yunnan) ( Skejo, 2017; the present study). Skejo (2017) summarized some information of Phaesticus (nymphs) from India (Assam, Mizoram). These nymphs are similar to P. mellerborgi (= P. azemii syn. nov.; Mahmood et al., 2007) and P. moniliantennatus ( Fig. 4 , h). We tentatively identified them as the former.

Figures

FIGURE 1. Distribution of the genus Phaesticus and its three species.

FIGURE 2. Phaesticus mellerborgi (Stål), macropterous form, female. a) dorsal view of body; b) front view of head; c) lateral view of body. Scale bars = 1 mm.

FIGURE 3. Phaesticus mellerborgi (Stål), brachypterous form. a) lateral view of male body; b) front view of male head; c) ventral view of female subgenital plate; d) dorsal view of female body; e) lateral view of female body. Scale bars=1 mm.

FIGURE 4. Phaesticus moniliantennatus (Günther). a) dorsal view of female body; b) lateral view of female body; c) dorsal view of female head and anterior pronotum; d) lateral view of female head; e) frontal view of female face; f) dorsal view of male body; g) lateral view of male body; h) lateral view of a female nymph. Scale bars a, b, f–h=2 mm; c–e=1 mm.