Miridiba hani Gao, 2021

Gao, Chuan-Bu, Bai, Ming, Fang, Hong & Li, Jun, 2021, Miridiba hani Gao, a new species from Hainan, China (Coleoptera: Scarabaeidae Melolonthinae: Rhizotrogini), with a new combination from Vietnam, Zootaxa 4996 (2), pp. 331-342 : 332-337

Miridiba hani Gao , new species

( Figs. 1–25 , 43 )

LSID: urn:lsid:zoobank.org:act:103893A5-B566-49D5-B8A6-1DE213062D96

Type locality. China, Hainan, Wanning, Xinglong Overseas Chinese Farm.

Type material (54 specimens). Holotype, ♂ ( SYSBM): “ Hainan Island, Yacheng, Xinglong / 1959.IV.6 / coffee leaf, Hainan team [handwritten, Traditional Chinese] // H. 149 [handwritten] // En-048823 / Sun Yat-sen University / The Museum of Biology [typeset, Chinese]” . Paratypes: ♀ ( SYSBM) (allotype), the same locality as holotype, but En-048820 ; 6 ♂ 7 ♀ ( SYSBM), the same data as holotype, but En-048811, En-048813, En-048814, En-048815, En-048816, En-048817, En-048819, En-048821, En-048822, En-048824, En-048825, En-048827, En-048828 ; 1 ♀ ( SYSBM), the same data as holotype, but En-048826 and an extra-label “N. 28 ?? 1965.iv.7 [handwritten]” ; 2 ♂ 1 ♀ ( IZCAS), the same locality as holotype, but 1959. IV. 7 at night, leg. Zeng-Zhuo Yang ; 1 ♂ ( IZCAS), the same locality as holotype, but leg. Yi-Chuan Hu, and an extra-label “32-N [handwritten]” ; 1 ♀ ( IZCAS), “ Hainan Island, Xinglong / Coffee Park / 1959. IV. 6 Zeng-Zhuo Yang [handwritten, Chinese]” ; 10 ♂ 12 ♀ ( IZCAS), “ Guangdong, Hainan Island / Xinglong Farm, Coffee / 1959. IV. 6 Yi-Chuan Hu [handwritten, Chinese]” ; 1 ♂ 2 ♀ ( IZCAS), the same data as previous paratypes, and an extra-label “32-N [handwritten]” ; 1 ♂ ( IZCAS), same data as previous paratypes, but the collector name lost ; 2 ♂ ( IZCAS), “ Hainan, Xinglong First District / Host Coffee leaf / 1960. V. 6 [handwritten, Chinese]” ; 4 ♀ ( IZCAS), same data as previous paratypes, but 1960. V. 16 ; 1 ♀ ( IZCAS), the same data as previous paratypes, and an extra-label “No. 9” .

Description of holotype, male. Habitus as in Figs. 1, 2 . Total body length 15.7 mm (from apex of frons to apex of pygidium), width across humeri 7.7 mm, body oval-elongate, strongly convex, dorsal surface glabrous.

Colour: Head, pronotum, scutellum, and basal elytra dark reddish-brown; antennae, legs, most of elytra, and abdomen reddish brown.

Head: Antennae with 10 antennomeres; antennal club with 3 antennomeres, 1.3 times longer than antenno- meres 3–7 combined, 0.9 times shorter than antennomeres 2–7 combined ( Fig. 3 ). Dorsal surface of clypeus dense punctate. Clypeus with anterior margin moderately emarginate and weakly reflexed. Clypeus wider and shorter than frons. Frons dense punctate. Fronto-clypeal suture clearly defined and sinuate ( Fig. 4 ). Frontal carina distinctly raised, arcuate and weakly obtuse. Interocular width equals 3.0 transverse eye diameters ( Fig. 4 ).

Mouthparts: Labrum strongly depressed medially; punctate and setiferous ventrally; dense microsetae near de- pression dorsally ( Fig. 5 ). Maxilla consists of cardo, stipes, galea, lacinia and maxillary palpi; cardo and stipes dense punctate and setiferous; galea with 6 sharp teeth; lacinia glabrous; maxillary palpi with 4 segments, fourth segment as long as segments 2–3 combined ( Figs. 6a, b ). Mentum with a triangular notch on anterior margin medially; each side of notch with 5 short setae ( Fig. 7 ). Mandible punctate and setiferous externally ( Fig. 8a ); dorsal surface flat, exposed apex smooth and rounded ( Fig. 8b ); molar lobe with long depression on distal portion (long triangle-shaped in left mandible, moderately long trapezoid in right mandible) and moderately wrinkled on proximal portion ( Figs. 8c, d ); incisor lobe with 2 sclerotised teeth (teeth sharp in left mandible and obtuse in right mandible ( Fig. 8e ).

Thorax: Pronotal surface sparsely punctate; distance between punctures more than three puncture diameters; punctures on disc smaller than those on head; pronotum widest at posterior 2/5; anterior margin smooth and flanged, with few short setae near posterior side; lateral margin crenulate, setiferous, and strongly expanded outwards, se- tae long and fine; posterior margin smooth and weakly depressed on lateral sides; few tiny setae sparsely along posterior margin; anterior and posterior angles obtuse ( Fig. 9 ). Prosternal process trapezoidal, concave medially. Ventral surface of thorax covered with long, soft setae; metepisternum narrow, 3.1 times longer than wide ( Fig. 10 ). Scutellum triangular, dorsal surface glabrous and sparsely punctate, 1.5 times wider than long; medial and posterior area without punctures ( Fig. 11 ). Dorsal surface of elytra glabrous; sutural costae developed; each elytron with 4 longitudinal flat stripes. Epipleura covered with a few setae except apex ( Fig. 1 ).

Legs: Pro- and mesofemora with dense setae ventrally; two rows of robust setae respectively at the middle of dorsal surface and near posterior margin; metafemora moderately narrow, 2.7 times longer than wide; ventral metafemora with a row of robust setae near posterior margin ( Fig. 12 ). Protibia tridentate; two apical teeth strongly sharp; basal tooth small and obtuse; a dorsal carina forking to medial protibia tooth; apical spur reaching basal 1/3 of protarsomere 1 ( Fig. 13 ). Meso- and metatibia with a transverse interrupted carina on the outer surface ( Fig. 14a ), with one pubescent spine at basal 1/4 of dorsolateral margin and seven small, obtuse spines on dorsointernal margin ( Fig. 14b ). Two apical spurs of metatibia of different size; lower spur short, lanceolate and sharp; upper spur long, blade-shaped and moderately obtuse. Apices of pro- and mesotarsomeres 1–4 with dense microsetae ventrally ( Fig. 15 ). Metatarsomere 1 as long as metatarsomere 2. Pro-, meso- and metatarsal claws each with a strong tooth medially ( Fig. 16 ).

Abdomen: Sternite 1 densely punctate and setiferous, setae short; sternites 2, 3, 4 with punctures and short setae sparse to dense toward lateral sides; sternite 5 moderately depressed in posterior half; ventral sternite 6 flat; sternites 5 and 6 with long, soft setae ( Figs. 17, 18 ).

Pygidium: 1.4 times wider than long; fan-shaped, sparsely punctate; centre slightly upheaved; distance between punctures more than 3 puncture diameters; apex obtuse, bearing long, soft hairs ( Figs. 18, 19 ).

Male genitalia. Shape as in Figs. 20, 22 . Phallobase: 1.3 times longer than parameres; anterior 1/3 reduced, dorsal surface with a depressed sulcus medially. Parameres: Proximal half of parameres nearly tubular shaped. Parameres consist of two dorsal and two ventral branches. Dorsal branches thicker and 0.9 times longer than ventral branches. Dorsal branches extended forward; left and right dorsal branches asymmetric and separated in dorsal view ( Fig. 22 ). Inner margins of both ventral branches connected, forming a suture medially; apices of ventral branches weakly expanded ventrally ( Fig. 23 ). Endophallus with temones on dorsum and epithelium on distal end; epithe- lium covered with few cone-shaped sensillae, dense soft sensillae, and a row of 7–8 spines proximally; terminal sac wrinkled; temones elongate slenderly, apophysis unseparated ( Fig. 24 ). Spiculum gastrale Y-shaped.

Allotype, female. Total body length 15.7, width across humeri 7.7 mm. Allotype differs from the holotype in the following respects: Antennal club 1.15 times longer than antennomeres 3–7 combined; 0.8 times shorter than antennomeres 2–7 combined. Clypeus shorter than frons; interocular width equals 3.5 transverse eye diameters. Metepisternum narrow, 3.9 times longer than wide. Apical spur of protibia reaching basal 2/5 of protarsomere 1. Dorsointernal margin of meso- and metatibia with six to seven small, obtuse spines. Metafemora broader than that of the holotype, 2.3 times longer than wide, anterior margin expanded forward. Ventral sternite 6 slightly protuber- ant ventrally. Pygidium 1.5 times wider than long.

Female genitalia. Female genitalia is of the tubular type ( Lindroth & Palmén 1970; Gao & Coca-Abia 2021) and comprises the genital chamber, accessory gland, median oviduct, bursa copulatrix, spermatheca and spermatheca gland ( Figs. 25a, b ). Genital chamber membranous, dorsal wall with anal fold and gonopore fold; posterior anal fold with two pairs of vestigial tergites; bilaterally symmetrical vestigial tergites located on both sides rectum. Two accessory glands site on both sides of the anterior end of the genital chamber, and each gland has a wrinkle kid- ney-shaped dark area in the end. Median oviduct with a pair of hardened epithelial areas; epithelium long and wide. Bursa copulatrix with a massive pouch at proximal part bearing plicate epithelium and small setae, and sclerotised peduncle connected to median oviduct. Spermatheca short and shape like a curved baseball-bat; spermatheca gland slender, nearly four times longer than spermatheca.

Variability of paratypes. Male paratypes and holotype are similar except in total body length: 15.6–15.9 mm, humeral width: 7.5–7.9 mm. Female paratypes and allotype are similar except in total body length: 15.4–17.3 mm, humeral width: 7.6–8.4 mm. The difference between male and female paratypes is scarce. In the females, the anten- nal club is no more than 1.2 times longer than antennomeres 3–7 combined, while that is no less than 1.3 times in the males.

Differential diagnosis. Gao & Coca-Abia (2021) established the morphotype Scutata of the genus Miridiba based on the genital characters. The morphotype is distinguished from the other morphotypes by its pronotum with punctures sparsely distributed; parameres with two dorsal branches asymmetrical, separated or connected; inner margins of two ventral branches connected; basal parameres without sutural scar in lateral surface; collum absent; bursa copulatrix with part of the peduncle striated. The morphological characters of M. hani new species conform to the features above ( Figs. 9 , 20, 22, 23 ), so the new species could be classified as a member of the morphotype Scutata. The differences among the three species of this morphotype are provided ( Table 1).

Miridiba hani new species can be separated from other Miridiba species by following combination of characters: Antennae with 10 antennomeres. Anterior margin of clypeus weakly reflexed. Frontal carina weakly obtuse. Mentum with five short setae along each side of the medial notch. Pronotal surface sparsely punctate; anterior mar- gin smooth and flanged, with few short setae near posterior side; lateral margin crenulate; posterior margin smooth and weakly depressed, with few tiny setae sparsely. Scutellum glabrous and sparsely punctate; middle and posterior area without punctures. Outer surface of meso- and metatibia with a transverse interrupted carina; dorsomedial margin of meso- and metatibia with seven small, obtuse spines. Parameres consist of two dorsal and two ventral branches; two dorsal branches asymmetrical; inner margins of ventral branches connected.

Distribution. China (Hainan: Wanning) ( Fig. 43 ).

Etymology. According to the type specimens’ labels, the collection place is Xinglong Farm of Yacheng town (Hainan Island). In the past 80 years, the administrative division of Hainan has changed a lot. Hainan was historically part of Guangdong Province, but in 1998 this island became a separate province. Xinglong once belonged to the Yaxian district from 1958 to 1959. Now this place has a formal name Xinglong Overseas Chinese Farm, and belongs to Wanning city. Yacheng once belonged to the Yaxian district from 1912 to 1984, but now it belongs to the Yazhou district of Sanya city. Xinglong Farm and Yazhou district are about 150 kilometres apart. Therefore, the correct type locality is Xinglong Farm of Wanning city. Prof. Shi-chou Han, Institute of Zoology of Guangdong Academy of Sciences, helped us verify the correct locality by perusing lots of literature and consulting some older adults on the administrative histories’ divisions of Yacheng and Xinglong. So, we named the new species for Prof. Han, who positively contributed to our work.

Chinese name. OiṘffiĤffl

Remarks. According to the collection labels of M. hani new species, the adult scarab beetle feeds on the coffee leaf. However, no information about the life cycle or habits of Miridiba hani new species is known. Given the potential pest status, we consider it urgent to collect further data on its distribution and biology. The distribution of the morphotype Scutata showed that all three species appear to be restricted to the southern provinces of China, the central and north provinces of Vietnam ( Fig. 43 ).

There are five Miridiba species distributed in Hainan Island up to now: Miridiba hani new species, M. frontalis

(Fairmaire, 1886), M. kuatunensis Gao & Fang, 2018 , M. sinensis (Hope, 1842) and M. sus (Moser, 1912) .

2010.

Figures

FIGURE 43. Distribution map of four Miridiba species.

FIGURES 1–2. Holotype of Miridiba hani Gao, new species. 1, habitus, dorsal view; 2, habitus, lateral view. Abbreviations: es, epipleural setae. Scale bar: 5.0 mm.

FIGURES 3–16. Holotype of Miridiba hani Gao, new species, head (3, 4), mouth parts (5–8), thorax (9–11) and legs (12–16). 3, antennae; 4, frons; 5, labrum; 6a, left maxilla; 6b, right maxilla; 7, mentum in ventral view; 8a, left mandible of outer side; 8b, left mandible of top side; 8c, left mandible of inner side; 8d, right mandible of inner side; 8e, left mandible of ventral side; 9, pronotum; 10, metepisternum; 11, scutellum; 12, metafemora; 13, protibia; 14a, metatibia of outer side; 14b, metatibia in lateral view; 15, mesotarsi; 16, metaclaws. Abbreviations: c, cardo; di, dorsointernal margin; dl, dorsolateral margin; g, galea; il, incisor lobe; l, lacinia; ml, molar lobe; n, notch; p, maxillary palpi; s, stipe. Scale bar: 0.1 mm for Fig. 16; 0.5 mm for Figs. 3, 5–8; 1.0 mm for Figs. 4, 9–15.

FIGURES 17–25. Holotype (17–24) and allotype (25) of Miridiba hani Gao, new speceis. 17, sternites 5 and 6 in ventral view; 18, pygidium in lateral view; 19, pygidium in dorsal view; 20, male genitalia in lateral view; 21, male genitalia in ventral view; 22, parameres in dorsal view; 23, parameres in ventral view; 24, endophallus in dorsal view; 25a, female genitalia; 25b, genital chamber.Abbreviations: ac, accessory gland; bc, bursa copulatrix; db, dorsal branches; el, epithelium; ep, endophallus; gc, genital chamber; mo, median oviduct; p, peduncle; pb, phallobase; pm, parameres; s, spermatheca; sg, spermatheca gland; sp, spine; t, temones; vb, ventral branches; vt, vestigial tergites. Scale bar: 1.0 mm for Figs. 17–21, 24, 25; 0.5 mm for Figs. 22, 23.