Mystilus carvalhoi Kim et Jung, 2020

Kim, Junggon & Jung, Sunghoon, 2020, Two new species of the genus Mystilus Distant (Hemiptera: Miridae: Mirinae) from Vietnam, with discussion on morphological variation based on molecular data, and a revised key for Mystilus species, Raffles Bulletin of Zoology 68, pp. 488-495 : 490-492

Mystilus carvalhoi Kim et Jung , new species

( Figs. 1 , 3A–D )

Material examined. Holotype male ( CNU), VIETNAM: Cuc Phuong National Park , 20°19′07″N 105°36′18″E, Ninh Binh Prov., on Gigantochloa sp. , 10 May 2017, J. Kim . Paratypes: 2 males and 1 female ( CNU), VIETNAM: same data as for holotype .

Diagnosis. Recognised by the following combination of characters: frons dark brown; first antennal segment almost dark brown; margin of compound eye reaching margin of head laterally; collar almost dark brown; second antennal segment longer than ½ third segment; scutellum dark brown, slightly tumid laterally; cuneus dark brown, slightly transparent; hypophysis of left paramere blunt, upper margin of hypophysis convex; right paramere rod-shaped, slightly swollen apically, hypophysis short and narrow; endosomal sclerite with densely tiny tooth ( Fig. 3C, D ).

Description. Male. Body elongate, length 4.55–4.68. COLOURATION: generally bluish brown with hyaline hemelytra ( Fig. 1A–C ). Head: almost dark brown; vertex brown; frons dark brown; clypeus brown; antennae almost dark brown; first antennal segment generally dark brown except for pale base. Thorax: pronotum bluish brown, variable in range of bluish region ( Fig. 1D–F ); collar dark brown; sometimes posterior part of pronotum with variable yellowish marking; scutellum distinct dark brown; hemelytra almost hyaline, base of hemelytra dark brown; commissure and posterior margin of corium dark brown; cuneus dark brown, slightly transparent; vein dark brown; femur almost pale brown except for dark apical part, with dark medial line and dark markings, inner part of femur entirely pale brown; tibia almost dark brown except for pale subapical part; tarsus dark brown. Abdomen: dark brown. SURFACE AND VESTITURE: not glabrous, dull; head with transverse wrinkle; pronotum deeply punctate; hemelytra glabrous with weakly punctate. STRUCTURE: Head: distinctly prognathous; vertex width wider than compound eye; antennae much longer than length of body, linear except for first segment; first antennal segment thicker than second antennal segment, apex of first antennal segment swollen; third antennal segment longest; proportion of first to fourth antennal segments 1.1: 2.8: 5.3: 2.3; labrum slightly shorter than first labial segment; labium exceeding hindcoxae. Thorax: pronotum trapezoid, longitudinal length longer than ½ basal maximal width; suture of collar obsolete; calli distinct swollen; scutellum slightly tumid laterally, not perfectly flat, anterior width shorter than ½ basal pronotal width, longitudinal length shorter than commissure; lateral margin of hemelytra almost straight; cuneus elongate; legs extremely long and slender; femur apically swollen. Abdomen: rounded, reaching to apex of cuneus. GENITALIA: left paramere with setae partly, hypophysis not sharp, blunt, upper margin of hypophysis convex ( Fig. 3A ); right paramere rod shaped, without setae, slightly swollen apically, hypophysis short and narrow ( Fig. 3B ); endosoma membranous with sclerites, sclerite oriented from ductus seminis, sclerite with densely tiny tooth ( Fig. 3C, D ).

Female. Body elongate, length 5.67. COLOURATION: as in male. SURFACE AND VESTITURE: as in male. STRUCTURE: as in male except for possessing genital tube at last abdominal segment.

Measurements (in mm). Male (n=3)/Female (n=1). Body length, clypeus–apex of membrane: 4.55–4.68/5.67; head length, excluding collar: 0.31–0.33/0.38; head width, including compound eyes: 0.83–0.85/0.92; vertex width: 0.45–0.46/0.47; 1 st antennal segment length: 1.15–1.17/1.22; 2 nd antennal segment length: 2.79–2.89/2.94; 3 rd antennal segment length: 5.33–5.46/5.88; 4 th antennal segment length: 2.31–2.40/2.99; total antennal length: 11.58–11.92/13.03; labial length: 2.14–2.16/2.38; anterior pronotal maximal width (straight): 0.75–0.76/0.79; mesal pronotal length: 0.81–0.83/0.87; posterior pronotal maximal width (straight): 1.05–1.10/1.22; anterior scutellar width: 0.51–0.53/0.69; mesal scutellar length: 0.43–0.49/0.65; commissure length: 0.82–0.91/1.10; outer embolial margin length (straight): 2.01–2.19/2.72; outer cuneal margin length (straight): 0.50– 0.56/0.65; maximal width across hemelytron: 0.57–0.59/0.67.

Etymology. Named after J.C.M. Carvalho, a taxonomist for Miridae who studied Mecistoscelini ; a noun in genitive case.

Host. Gigantochloa sp. ( Poaceae : Bambusoideae ), the same plant as the host of M. fredrici , new species, above ( Fig. 4 ).

Distribution. Vietnam (Northern).

Remarks. This species is similar in general appearance to the species M. priamus , but it can be distinguished by the larger body more than 4.5 mm and the length of second antennal segment longer than ½ length of third antennal segment. According to the previous studies on M. priamus ( Distant, 1904; Lansbury, 1963), M. priamus is not more than 4 mm, making it the smallest species in this genus.

Figures

Fig. 1. Dorsal and lateral habitus with variation of Mystilus carvalhoi, new species. A, holotype, male; B, paratype, female; C, lateral view of male; D–F, variation of pronotum colouration. Scale bar = 1 mm.

Fig. 3. Parameres and endosome of Mystilus spp. A–D, M. carvalhoi, new species; E–H, M. frederici, new species. A, E, left paramere; B, F, right paramere; C, D, G, H, endosoma; sc, sclerite; sg, secondary gonopore. Scale bar = 0.1 mm.

Fig. 4. Host plant, Gigantochloa sp.