Cryptostemma miyamotoi, Yamada & Hayashi, 2019

Yamada, Kazutaka & Hayashi, Masami, 2019, Two new species of the genus Cryptostemma from Japan (Hemiptera: Heteroptera: Dipsocoridae), Acta Entomologica Musei Nationalis Pragae 59 (2), pp. 381-390 : 382-384

Cryptostemma miyamotoi sp. nov.

( Figs 1–4 , 9 , 11–19 , 29 )

Cryptostemma sp. A: HIURA (1967): 80.

Type material. HOLOTYPE: ♁ ( Figs 1–2 ), ‘JAPAN: Shimane Pref.: / Izumo- shi: Inome-cho / Inome-gawa / 35.440804, 132.710732 / 4.vii.2015: Masakazu HAYASHI leg.’ [printed], [a card with locality data and collector in Chinese script, printed]; mounted on a triangular card, in intact condition ( TKPM) . PARATYPES: JAPAN: HONSHU: same data as holotype, 1 ♁ ( Fig. 9 ) 1 ♀ ( TKPM). SHIKOKU: Tokushima Pref.: 1 ♀, Tokushima-shi, Kamihachiman-chô, Sonosegawa-Riv., 11.vi.2007, K.Yamada ( TKPM); 1 ♁ ( Fig. 29 ), Sanagouchi-son, Shimo, 34°00 ′ 45 ″ N, 134°28 ′ 45 ″ E, 36 m alt., 21.v.2016, K. Yamada ( TKPM); 1 ♀, same locality, 4.vi.2016, K. Yamada ( TKPM); 2 ♀♀ (one in Figs 3–4 ), same locality, 26.iv.2018, K. Yamada ( TKPM); 1 ♁, same locality, 18.v.2018, K.Yamada ( TKPM); 1 ♀, Kamiyama-chô, Jinryô-hon-uetsuno, 13.vii.1953, I. Hiura ( OMNH); 1 ♁, same locality, 20.vii.1953, I. Hiura ( OMNH); 1 ♁ ( Figs 11–18 ), same locality, 12.viii.1953, I. Hiura ( OMNH); 12 ♁♁ 7 ♀♀ (one in Fig. 19 ), Kamiyama-chô, Jinryô, 27.viii.1953, I. Hiura ( OMNH, ELKU). KYUSHU: Nagasaki Pref.: 1♁ 1♀, Nagasaki-shi,Mieda-chô, 32°49 ′ 13 ″ N, 129°43 ′ 57 ″ E, 7 m alt., 29.iii.2018, K. Yamada ( TKPM).

Differential diagnosis. Recognized by the combination of the following characters: Body small in size (1.4–1.7 mm), uniformly yellowish-brown coloration, narrowly darkened posterior angles of pronotum, left side of sternite VII branched in middle, very large and U-shaped right laterotergite VIII with mitten-shaped apex of large anterior process, and large asymmetrical sternite VIII. It is most similar to C. digitum Wu, 1967 in size, coloration, and general abdomen configuration, but distinguished from that species by the left side of sternite VII branched in middle (in C. digitum , spatulate, apically truncated), left laterotergite VIII expanded at apex with triangular subapical flange (in C. digitum , not expanded at apex, with no flange), and posterior process of right laterotergite VIII slender and narrowed apicad (in C. digitum , bearing an elongate process basally and bifurcated at apex).

Description. Male. Body elongate-oval, small (1.4–1.7 mm). Coloration ( Figs 1–2 , 29 ). Head uniformly yellowish--brown; eyes and ocelli dark red; antennae pale yellow to brown; labium pale yellow. Pronotum yellowish-brown, with posterior angles narrowly darkened. Scutellum overall yellowish-brown. Forewing brownish, somewhat darker than pronotum. Venter of thorax uniformly yellowish-brown. Abdomen dark brown. Surface and vestiture. Head impunctate, sparsely covered with short semi-erect setae; clypeus, bucculae, and labrum with dense semi-erect setae ( Figs 1, 3 ), with 5–6 pairs of very long erect setae on each side of clypeus, inner side of antennal insertion, and on each side behind ocellus; apex of clypeus with single long erect seta; eyes with scattered short setae. Antennal segments I and II with short semi-erect setae ( Figs 1, 3 ); segments III and IV sparsely covered with mix of short and longer setae, of which longest setae much longer than twice width of corresponding segment ( Figs 1, 3 ). Labium sparsely covered with mix of short and longer setae. Pronotum impunctate, with sparse short setae, and with pair of relatively long setae near posterolateral angles. Legs shiny, densely covered with short setae. Forewings with extremely short setae on marginal vein. Abdomen densely covered with short reclining setae; left side of sternite VII with dense and long pilosity on middle surface ( Figs 11–13 ); left laterotergite VIII with long stout setae on basal 1/3 of inner and outer surface ( Figs 11–12, 14 ); right laterotergite VIII basally with distinctively longer setae ( Figs 11, 15 ); sternite VIII and pygophore densely covered with mix of short and longer setae ( Figs 11–12 ); left paramere bearing longer stout setae intermixed with short setae, apical process with five short setae on middle part ( Figs 16–17 ); right paramere with short setae and row of very short setae on outermost margin ( Fig. 18 ).

Structure. Head triangularly produced anteriorly with round apex ( Figs 1, 3 ); head width across eyes approximately 1.7 times wider than interocular distance; eyes small, granulate; ocellus touches median margin of respective eye. Antennal segment I stout, slightly longer than its diameter; segment II pyriform, almost same width as segment I, approximately twice longer than segment I; segments III longer than segment IV. Labium reaching to posterior part of prosternum; segment I wider than other segments, slightly longer than width; segment III approximately 1.3 times longer than segment II; segment IV approximately as long as segment II. Thorax: pronotum trapezoidal in dorsal view ( Figs 1, 3 ), approximately 0.6 of its basal width in length; anterior margin slightly curved; lateral margin weakly carinate; posterior margin slightly concave; pronotal collar sulcus developed only laterally; posterior disc medially with transverse shallow sulcus. Legs: each femur incrassate, with fore femora rather thickened; fore tibiae thickened toward apex, fore tibiae with scattered 5–6 long slender spines, and apically with dense slender spines on ventral surface (without tibial comb).; mid tibiae slightly expanded at apex, bearing several spines on apicoventral and outer surfaces, with spine shorter than maximum width of mid tibia; hind tibiae distinctly longer than fore and mid tibiae, bearing 4 longer spines on outer surface and 5 apical spines, of which longer spine approximately as long as maximum width of hind tibia; tarsal formula 3-3-3. Forewing: surpassing apex of abdomen; marginal vein loop cut by costal fracture; venation as shown in Fig 9 . Pregenital abdomen: all segments strongly asymmetrical; right laterotergites II–VII not clearly divided into dorsal and ventral laterotergites (weakly sclerotized between dorsal and ventral laterotergites) ( Figs 11–12 ); mediotergite III–VI narrowed dextrally ( Fig. 11 ); mediotergite VII enlarged, posterior margin concave medially ( Fig. 11 ); left laterotergites present on segments IV and VII (not divided into dorsal and ventral laterotergites), left laterotergites V and VI fused with respective sternites ( Figs 11–12 ); left side of sternite VII produced, branched in middle with long anterior process and short posterior process ( Figs 11–13 ); spiracles located on laterotergites IV–VII (on left side, located on laterotergites IV–VI and sternite VII), and subbasally on left laterotergite VIII ( Figs 11–14 ). Genitalia: mediotergite VIII asymmetrical, complicatedly shaped, with small dorsally elevated projection on left side ( Fig. 11 ); left laterotergite VIII basally bent, weakly twisted, expanded at apex, with triangular subapical flange ( Figs 11, 14 ); right laterotergite VIII very large, flattened, U-shaped with large anterior process and small posterior process, large anterior process apically mitten--shaped, small posterior process slender and narrowed apicad ( Figs 11, 15 ); sternite VIII very large, asymmetrical, narrowed dextrally in ventral view. Pygophore large and oval, slightly shorter than sternite VIII, anterodorsally with ridges and process (anterodorsal projection) ( Figs 11–12 ); anterodorsal projection very large, hand-like shaped with small dorsally elevated process on each corner ( Fig. 11 ); left paramere elongate, subequal in length to left laterotergite VIII, with two basal extensions and apical process, two basal extensions present with distinct anterior extension and oval posterior extension (basal process), apical process slender and apex weakly curved posteriad ( Figs 11–12, 16–17 ); right paramere short and flattened, with two large rounded lobes, of which anterior one with small triangular process ( Figs 11, 18 ).

Female ( Figs 3–4 , 19 ). Similar to male in coloration, surface, and vestiture, slightly smaller than male, rather ovoid; tarsal formula 2-2-3; forewing usually not surpassing apex of abdomen; abdomen symmetrical. Genitalia: spermatheca as shown in Fig. 19 ; seminal capsule spherical, very tiny (diameter less than 0.05 mm), turns into caudal appendage on one side and forms short canal leading to spermathecal duct; spermathecal gland fused on top of seminal capsule, bulbous, very small.

Measurements (♁ n = 8 / ♀ n = 7, holotype in parentheses). Body length 1.46–1.66 (1.46) / 1.33–1.62; head width across eyes 0.30–0.34 (0.30) / 0.31–0.33; interocular distance 0.17–0.21 (0.20) / 0.20–0.22; length of antennal segments I – 0.05–0.07 (0.06) / 0.05–0.07, II – 0.10–0.12 (0.10) / 0.11–0.12, III – 0.31–0.38 (0.31) / 0.30–0.39, and IV – 0.26–0.30 (0.26) / 0.25–0.31; length of labial segments II – 0.08–0.09 (0.08) / 0.07–0.08, III – 0.11–0.12 (0.11) / 0.11–0.13, and IV – 0.08–0.09 (0.08) / 0.08–0.09; length of pronotum along meson 0.23–0.25 (0.23) / 0.24–0.26; width of pronotum 0.40–0.47 (0.40) / 0.43–0.46; length of forewing 1.06–1.30 (1.06) / 0.90–1.20; length of hind tibiae 0.45–0.49 (unmeasurable) / 0.43–0.45.

Etymology. Named in honor of the late Dr. S. Miyamoto, in recognition of his outstanding contributions to study of Dipsocoromorpha .

Distribution. Japan (Honshu, Shikoku, Kyushu).

Figures

Figs 1‒8. Habitus of Japanese Cryptostemma spp., dorsal (1, 3, 5, 7) and lateral (2, 4, 6, 8) views. 1‒4 – Cryptostemma miyamotoi sp. nov., holotype, male (1‒2) and female (3‒4); 5‒8 – C. pavelstysi sp. nov., holotype, male (5‒6) and female (7‒8). Scale bars = 0.5 mm.

Figs 9‒10. Right forewings of Japanese Cryptostemma spp. 9 – Cryptostemma miyamotoi sp. nov., male; 10 – C. pavelstysi sp. nov., male.Abbreviations: cf = costal fracture; clf = claval fracture.Scale bars = 0.2 mm.

Figs 11‒19. Morphological details of Cryptostemma miyamotoi sp. nov., male (11‒18) and female (19). 11‒12 – abdomen (mediotergite II and sternite II omitted), dorsal (11) and lateral (12) views; 13 – left side of sternite VII, laterodorsal view; 14 – left laterotergite VIII, laterodorsal view; 15 – right laterotergite VIII, laterodorsal view; 16‒17 – left paramere, dorsal and anterior views; 18 – right paramere, dorsal view; 19 – spermatheca.Abbreviations: adpp = anterodorsal projection of pygophore; an = anophore; app = apical process of paramere; bpp = basal process of paramere; g = spermathecal gland; lp = left paramere; lt4‒8 = laterotergite IV‒VIII; mt8 = mediotergite VIII; py = pygophore; rp = right paramere; sc = seminal capsule; st4, 7, 8 = sternite IV, VII, VIII. Scale bars = 0.2 mm for 11‒12; 0.1 mm for 13‒18; 0.05 mm for 19.

Figs 29‒32. Living individuals and habitats. 29 – Cryptostemma miyamotoi sp. nov., male; 30 – C. pavelstysi sp. nov., male; 31 – habitat of C. miyamotoi, Sonosegawa Riv., Sanagouchi-son, Tokushima Pref.; 32 – habitat of C. pavelstysi, near Nagura Dam, Ishigaki Is.