Taxonomic review of Kokeshia Miyamoto, 1960 from China, with description of ten new species (Hemiptera: Heteroptera: Schizopteridae)

Abstract. The species of Kokeshia Miyamoto, 1960 from China are reviewed, K. hsiaoi Ren & Zheng, 1992 is redescribed, and ten new species from China are described. Among these new species, K. baii sp. nov., was collected from Hong Kong, and the other nine, K. acutiformis sp. nov., K. bui sp. nov., K. caii sp. nov., K. drepanoides sp. nov., K. hilli sp. nov., K. pengae sp. nov., K. redeii sp. nov., K. renae sp. nov. and K. weirauchae sp. nov., from Yunnan. Thus, the number of known species of this genus is increased from eight to eighteen. Photographs of the habitus, forewing, abdomen and genitalic structures; drawings and scanning electron micrographs of male abdomen and genitalic structures are provided. A key to all the species currently recognized in the genus Kokeshia is presented, a distribution map and checklist for all known species is provided.


Introduction
, also known as minute litter bugs, is one of the basal infraorders within true bugs. Their tiny body size and cryptic habits cause them to be one of the least known groups in Heteroptera Latreille, 1810. This infraorder currently comprises 6 families and about 430 species worldwide (Štys 1995;Weirauch et al. 2018;Knyshov et al. 2020). Schizopteridae Reuter, 1891, the largest family of Dipsocoromorpha, had been divided into 3 subfamilies: Hypselosomatinae Esaki & Miyamoto, 1959, Ogeriinae Emsley, 1969and Schizopterinae Reuter, 1891by Emsley (1969, and this classifi cation system was accepted by several subsequent authors Hill 2004 = media plht8 = process of left hemitergite VIII prht8 = process of right hemitergite VIII prt8 = process on the right portion of tergite VIII py = pygophore R = radius rht8 = right hemitergite VIII rp = right paramere Sc = subcosta scc = subcostal cell s2−7 = sternite of abdominal segments II to VII tc = trapezoidal cell tp = triangular process t1−8 = tergite of abdominal segments I to VIII X = abdominal segment X XI = abdominal segment XI 1An = fi rst anal vein 2An = second anal vein

Diagnosis
The genus Kokeshia can be recognized among Schizopterinae (including the former ʻOgeriinaeʼ) by the following combination of characters: (a) labium short, four-segmented; (b) tarsal formula 2-2-3; (c) forewing with costal fracture, C+Sc, R+M and R prominently thicker than other veins, medial fracture very short, subcostal cell elongated triangular, trapezoidal cell with fi ve emanating veins, free distal remigial veins usually with a fused apical portion, and terminate before wing margin; (d) male abdominal tergite VII and sternite VII slightly asymmetrical, tergite VIII usually subdivided into two parts, and left hemitergite VIII usually with process; (e) apical portion of phallus sclerotized, tubular and coiled. The venation of forewing is similar to genus Caucanannus Weirauch et al., 2020 andGuapinannus Wygodzinsky, 1951 in welling-developed costal fracture; prominently thick C+Sc, R+M and R; R with only one branch; abdomen of male well sclerotized, and near symmetrical, with well-developed tergites, but it can be distinguished from the latter two genus by M normal, without wing organ or gland; free distal remigial veins usually with a fused apical portion, and terminate before wing margin, instead of reaching to wing margin.

Redescription
BODY. Body small (about 1.07-1.49 mm), suboval . Only macropterous male and brachypterous female reported up to now (hind wings absent in female).
COLORATION. Body color relatively uniform, light brown to brown; antennae, labium and legs yellowish brown ( Fig. 1A-C). SURFACE AND VESTITURE. Cuticle matt; head, thorax, veins of forewing, and abdomen with relatively dense, short, and adpressed setae. Anteclypeus with long setae; antennal segments I and II with short curved setae, segments III and IV with very long semi-erect to erect setae. Legs with relatively long, rather dense semi-erect setae.
HEAD. Head short and vertical, wider than long in frontal view. Eyes small, wide of eye about ⅛ × as wide as head in frontal view, raspberry appearance; ocelli present in macropterous male and absent in brachypterous female, located on anterior portion of fronto-vertex close to eyes in male. Labium short, 4-segmented, reaching to middle coxae, segment I stoutest, segments II and III subequal in length and diameter, segment IV longest and tapering to tip. Antennal segments I and II thick and short, subequal in length; segments III and IV slender, subequal in length as well.
THORAX. Pronotum of male broad, near trapezoid, about 3 /5 × as long as wide, with distinct collar; collar short and broad, about 1 /6 × as long as pronotum, middle part of posterior margin concave. Pronotum of female smaller than male, posterior margin slightly arc-shaped concave. Scutellum small, with small tongue-shaped apex, two small pits located in middle area near base. Tarsal formula in both sexes is 2-2-3. Metasternum with high, rounded central process (Fig. 1C). Forewings of male exceed apex of abdomen, costal fracture distinct. Venation unique, C+Sc, R+M and R prominently thicker than other veins, medial fracture very short, subcostal cell elongated triangular, trapezoidal cell with fi ve emanating veins, free distal remigial veins usually with fused apical portion, and terminate before wing margin; subcostal cell triangular and elongate, with elongate quadrangular basal and elongate pentagonal discal cell (Fig. 1A). Forewings of female short, surpassing posterior margin of tergite IV (K. esakii  to reaching tergite VII (K. martensi Štys, , K. similis Štys, 1985Štys, and K. stysi Rédei, 2008. ABDOMEN. Pregenital abdomen strongly sclerotized, tergites I and II fused together, can be distinguished by a transverse groove; sternite I absent, sternites II and III fused, boundary could not be recognized (Fig. 1D). Tergite VII of male large, slightly asymmetrical, sternite VII large, almost symmetric to slightly asymmetrical, forming a bowl-shaped subgenital plate. Sternite VIII of male probably absent, invisible in appearance, tergite VIII of male in all except K. acutiformis sp. nov. subdivide into two asymmetrical hemitergites, left hemitergite usually with process in different shapes and size (key diagnostic character for species identifi cation) (Figs 1D−G, 2A−B).
GENITALIA. Pygophore asymmetrical, dorsally separated in appearance. Parameres strongly asymmetrical, distal projection of both left and right paramere elongate and fl attened, but left paramere usually with angulate projection at base (Fig. 2D−G). Phallus with large basal process, apical portion sclerotized, tubular and coiled ( Fig. 1D−E). Segment X asymmetrical, ring-shaped, segment XI membranous. Genitalia of female simple, tergite VIII and IX strongly sclerotized, visible in dorsal view, sternite IX with sclerotized intervalvular membrane. COLORATION. Body yellowish brown to light brown, appendages yellowish brown ( Fig. 1A-C). Surface, vestiture and general structures as in generic description, except mentioned below.  HEAD. Interocular distance 0.55-0.59 × length of maximum width across eyes.
THORAX. Humeral width 1.66-1.68 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 26A).
ABDOMEN. Tergite VII slightly asymmetrical, right portion wider than left portion, sternite VII nearly symmetrical. Tergite VIII not subdivided into two hemitergites, only a long, fl attened, acuminate process at right portion of tergite VIII, process bent at about ⅓ from its apex (

Female
Unknown.

Distribution
China: Yunnan (Fig. 32).   THORAX. Humeral width 1.64-1.75 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An distinctly darker than wing surface, other veins darker than wing surface (Fig. 26B).
GENITALIA. Pygophore slightly asymmetrical, dorsal surface with rows of microtrichia, posterior area with relatively long setae. Parameres strongly asymmetrical, left paramere (Figs 3E, 4F-G) with broadly rounded laminate extension directed dorsal near base, and with fl attened and elongate distal projection somewhat curved inward; right paramere (Figs 3E, 4D-E) with fl attened and blunt distal projection. Apical portion of phallus (Figs 3D-E, 4H) tubular, long, forming more than one and a half coils outside of pygophore.

Female
Unknown.

Diagnosis
Kokeshia bui sp. nov. can be recognized from other species of Kokeshia by male hemitergite VIII (Figs 5D-G, 6A-B) elongate, the left lateral margin slightly concave from about ⅓ of its apex, the posterior portion with an elongated triangular process, surpassing posterior margin of pygophore, right lateral margin of it with about nine subparallel, thick spiniform microtrichia.

Etymology
The species epithet is derived from and dedicated to Prof. Wenjun Bu (Institute of Entomology, Nankai University, China), recognizing his contributions to the study of taxonomy, phylogeny and biogeography of Heteroptera, and the taxonomy of Cecidomyiidae (Diptera). THORAX. Humeral width 1.67-1.78 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An distinctly darker than wing surface, other veins darker than wing surface (Fig. 26C).

Holotype
ABDOMEN. Tergite VII and sternite VII slightly asymmetrical. Tergite VIII subdivided into two hemitergites, left hemitergite VIII with elongated triangular process, right margin with about 9  subparallel, thick spiniform microtrichia (Figs 5E, G, 6A−B). The basal portion of process bearing numerous small round projections. Short to moderate length microtrichia located at surface of process, ends of these microtrichia split into 2 to 5 branches (Fig. 5G). Right hemitergite VIII subtriangular, posterolateral portion projecting posteriad, with thin setae at its posterolateral margin.
GENITALIA. Pygophore slightly asymmetrical, dorsal surface densely covered with groups of setae on small, tightly connected projections, posterior area with relatively long setae. Parameres strongly asymmetrical, left paramere (Figs 5E, 6E-F) with broadly rounded laminate extension directed dorsal near the base, and with fl attened and elongate distal projection slightly curved inward; right paramere (Figs 5E, 6G-H) with fl attened and blunt distal projection. Apical portion of phallus (Figs 5D-E, 6D) tubular, relatively long, forming one complete coil outside of pygophore.

Female
Unknown.

Diagnosis
The male of K. caii sp. nov. is similar to K. weirauchae sp. nov., but can be recognized from the latter by the left lateral margin of the hemitergite VIII strongly concave from about ⅓ of its apex, and the apical portion of hemitergite VIII with a fi nger-shaped process, which without any thick spiniform microtrichia, and with numerous microtrichia which the apex split into 2 to 5 branches (Figs 7D-G, 8A-B).

Etymology
The species epithet is derived from and dedicated to Prof. Wanzhi Cai (College of Plant Protection, China Agricultural University, China), recognizing his contributions to the study of taxonomy, morphology and phylogeny of Heteroptera.    COLORATION. Body brown, appendages yellowish brown ( Fig. 7A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.69-1.82 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An distinctly darker than wing surface, other veins darker than wing surface (Fig. 26D).
ABDOMEN. Tergite VII and sternite VII slightly asymmetrical. Tergite VIII subdivided into two hemitergites, left hemitergite VIII with fi nger-shaped process, and with numerous semi-erect, short to moderate long microtrichia on surface, and ends of these microtrichia split into 2 to 5 branches (similar to setae on process of hemitergite VIII of K. bui). Basal portion of process with scale-like projections, with 1 to 6 short microtrichia located on posterior margin of each one of them. Right hemitergite VIII simple, posterolateral portion round, projecting posteriad, outer margin with microtrichia (Figs 7E-F, 8H).
GENITALIA. Pygophore slightly asymmetrical, dorsal surface with groups of microtrichia on small, tightly connected projections, posterior area with relatively long setae. Parameres strongly asymmetrical, left paramere (Figs 7E, 8C-D) with broadly rounded laminate extension directed dorsal near base, and with fl attened and elongate distal projection; right paramere (Figs 7E, 8F-G) with fl attened and blunt distal projection. Apical portion of phallus (Figs 7D-E, 8E) tubular, forming nearly one complete coil outside of pygophore, apex thickened and forming a depression on one side.

Female
Unknown.

Etymology
The species epithet is derived from the Greek adjective ʻdrepanoidesʼ, means ʻsickle-shapedʼ, and refers to the curved, sickle-shaped process of tergite VIII.  COLORATION. Body light brown to brown, appendages yellowish brown (Fig. 9A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.69-1.77 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 26E).
ABDOMEN. Tergite VII and sternite VII slightly asymmetrical. Tergite VIII subdivided into two hemitergites, left hemitergite VIII with a fl attened, curved, sickle-shaped process, and horizontally directed mesad; prominent setae near its inner margin (Figs 9D

Female
Unknown.

Etymology
The species epithet is derived from and dedicated to Mr Lionel Hill (Tasmanian Department of Primary Industry, Water and Environment, Australia), recognizing his contributions to the study of taxonomy of Dipsocoromorpha (mainly in the Australian region). COLORATION. Body brown, appendages yellowish brown (Fig. 11A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.72-1.88 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 26F).  ABDOMEN. Tergite VII and sternite VII slightly asymmetrical. Tergite VIII subdivided into two hemitergites, posterior margin of left hemitergite VIII (Figs 11D-E, G, 12A−B) introduced into fl attened, nearly quadrangular process, left posterolateral margin with raised projection, bearing about 7 thick, basal-curved spiniform microtrichia; right posterolateral margin of process with about 7 parallel, thick, basal-curved spiniform microtrichia. Basal portion of process with numerous small round pits and micro teeth. Right hemitergite VIII with long, stick shaped process projecting posteriad (Figs 11E−F, 12E).
GENITALIA. Pygophore slightly asymmetrical, dorsal surface with dense microtrichia, posterior area with relatively long setae. Parameres strongly asymmetrical, left paramere (Figs 11E, 12G-H) with broadly blunt laminate extension directed dorsal near base, and with fl attened and relatively broad distal projection, and slightly curved inward from middle of it; right paramere (Figs 11E, 12C-D) with fl attened, round and relatively slender distal projection. Apical portion of phallus (Figs 11D-E, 12F) tubular, slender, forming less than one and a half coils outside of pygophore.

Female
Unknown.

Diagnosis
Kokeshia hsiaoi can be recognized from all other species of Kokeshia by tergite VIII subdivided into two hemitergites, left hemitergite VIII with an elongate, slender, curved process with an appendage split into 3-5 branches (Figs 13D   COLORATION. Body yellowish brown to light brown, appendages yellowish brown (Fig. 13A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.69-1.76 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 26G).
GENITALIA. Pygophore simple, asymmetrical, dorsal surface with dense microtrichia. Posterior margin of right dorsum with a triangular process (

Female
Unknown.

Diagnosis
The male of K. pengae sp. nov. is similar to K. oroszi, but can be distinguished from the latter species by an obviously large body size 1.20-1.29 mm, whereas 1.04 in K. oroszi; process of left hemitergite VIII fl agelliform, produced from left margin of left hemitergite VIII, whereas in K. oroszi, process of left hemitergite VIII fl agelliform, produced from posterior margin of left hemitergite VIII; apical portion of phallus short, slightly curved, forming about a half coil outside of pygophore, whereas in K. oroszi, apical portion of phallus longer and curved, forming about one incomplete coil outside of pygophore.

Etymology
The species epithet is derived from and dedicated to Prof. Yanqiong Peng (Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, China), appreciating her kind help during our fi eld works in Xishuangbanna and recognizing her contributions to the study of co-evolution of fi g and fi g wasps.  COLORATION. Body light brown to brown, appendages yellowish brown (Fig. 15A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.62-1.84 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 26H).

Female
Unknown.

Etymology
The species epithet is derived and dedicated to Dr Rédei Dávid (NCHU) recognizing his contributions to the study of taxonomy and morphology of Dipsocoromorpha and Heteroptera. COLORATION. Body yellowish brown to light brown, appendages yellowish brown (Fig. 17A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.75-1.84 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 27A).

Female
Unknown.

Etymology
The species epithet is derived from and dedicated to Prof. Shuzhi Ren (Institute of Entomology, Nankai University, China), recognizing her contributions to the study of egg morphology of Heteroptera and the study of taxonomy of Chinese Heteroptera.   COLORATION. Body light brown to brown, appendages yellowish brown ( Fig. 19A-C). Surface, vestiture and general structures as in generic description, except mentioned below.
THORAX. Humeral width 1.73-1.85 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 27B).
ABDOMEN. Tergite VII and sternite VII slightly asymmetrical. Tergite VIII subdivided into two hemitergites, left hemitergite VIII with subtriangular process, with numerous semi-erect microtrichia on surface, ends of microtrichia unbranched or split into two to four branches G,. Basal portion of the process with sparsely short microtrichia. Right hemitergite VIII with subtriangular posterolateral portion projecting posteriad, bearing numerous relative long microtrichia at apex (Figs 19D−F, 20B−C).
GENITALIA. Pygophore simple, asymmetrical, dorsal surface with relative dense small round projections and short setae, posterior portion of with relatively long setae. Parameres strongly asymmetrical, left paramere (Figs 19E, with broadly rounded laminate extension directed dorsal near base, and with fl attened and broad distal projection, and curved inward; right paramere (Figs 19E, 20H-I) with fl attened, round distal projection. Apical portion of phallus (Figs 19D-E, 18E) tubular, forming more than one coil outside of pygophore.

Female
Unknown.
THORAX. Humeral width 1.72-1.85 × as long as middle length of pronotum. Venation of forewing in accordance with general pattern of genus. C+Sc, R+M, R and basal portion of 1An darker than wing surface, other veins slightly darker than wing surface (Fig. 27C).
ABDOMEN. Tergite VII and sternite VII slightly asymmetrical. Tergite VIII subdivided into two hemitergites, left hemitergite VIII with curved, fi nger-shaped process, with about six thick spiniform microtrichia at its ventral side; besides, numerous semi-erect microtrichia at its surface, and ends of microtrichia unbranched or split into two to four branches. Basal portion of process with sparsely short microtrichia ( Fig. 21D-E, G). Right hemitergite VIII with triangular posterolateral portion projecting posteriad (Figs 21F, 22G).
GENITALIA. Pygophore simple, asymmetrical, dorsal surface with small, relative dense round projections and short setae, posterior area with relatively long setae. Parameres strongly asymmetrical, left paramere (Figs 21E, 22C-D) with near round laminate extension directed dorsal near base, and with fl attened and broad distal projection, and slightly curved inward; right paramere (Figs 21E, 22E-F) with fl attened, blunt distal projection. Apical portion of phallus (Figs 21D-E, 22G) slender and tubular, forming more than two and a half coils outside of pygophore.   Kokeshia Miyamoto, 1960 1. Tergite VIII not subdivided into two hemitergites, only a long, fl attened, acuminate process on the right portion of tergite VIII, bent at about ⅓ from its apex (Fig. 28A)  3. Process of left hemitergite VIII signifi cantly long, almost reaching the width of tergite VII, the process with an appendage split into three to fi ve branches ( Fig. 17D; Ren & Zheng 1992: 191       ; red open triangle = K. hilli sp. nov.; blue solid squares = K. hsiaoi ; red open square = K. martensi Štys, 1985; yellow solid square = K. oroszi ; yellow open triangle = K. pengae sp. nov.; green open hexagon = K. redeii sp. nov.; yellow open square = K. renae sp. nov.; yellow solid triangle = K. similis Štys, 1985; blue solid triangle = K. stysi ; blue open square = K. weirauchae sp. nov.; red solid triangles = K. xiei ; red solid square = K. zhengi  Morphologically, Kokeshia is similar to Caucanannus and Guapinannus in welling-developed costal fracture; prominently thick C+Sc, R+M and R; R with only one branch; abdomen of male well sclerotized, and near symmetrical, with well-developed tergites. Although they are different in some wing and genital characteristics, they may still be the closest relatives. In the future, further taxonomic and systematic studies of Kokeshia should pay more attention to comparative morphological studies with Caucanannus and Guapinannus.