Cryptostemma pavelstysi, 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 : 386-388

Cryptostemma pavelstysi sp. nov.

( Figs 5–8 , 10 , 20–28 , 30 )

Type material. HOLOTYPE: ♁ ( Figs 5–6 ), ‘JAPAN: Ishigaki-jima, / Miyara-gawa, / 24°25 ′ 32 ″ N 124°12 ′ 03 ″ E, / 63 m, 19–20 XI 2017, / K. Yamada’ [printed]; mounted on a triangular card, in intact condition ( TKPM) . PARATYPES: JAPAN: RYUKYUS: Ishigaki-jima Is.: 18 ♁♁ (one in Fig. 10 , one in Figs 20–27 ) 12 ♀♀ (one in Figs 7–8 , one in Fig. 28 ), same data as holotype ( TKPM, NMPC); 23 ♁♁ (one in Fig. 30 ) 5 ♀♀, near Nagura Dam, 14.xi.2018, K.Yamada ( TKPM, NMNS); 2♁♁ 3♀♀, Shiramizu, 17.iii.2000, M. Hayashi et al. ( TKPM).

Differential diagnosis. Recognized by the combination of the following characters: Body small in size (1.4–1.7 mm), reddish-brown to darker orange-brown head and pronotum, pronotum being widely darkened at posterior angles and sometimes darkened along posterior margin, smoky dark brown forewings with 2 obscure paler markings on area between costal fracture and claval fracture, apex of left side of sternite VII truncate, very large and U-shaped right laterotergite VIII with knife-shaped large anterior process, and large asymmetrical sternite VIII. Similar in general appearance and general configuration of abdomen to C. digitum and C. miyamotoi , but distinguished from C. digitum by the knife-shaped large anterior process of right laterotergite VIII (in C. digitum , anterior process of right laterotergite VIII apically bifurcated), and from C. miyamotoi by the shape of left side of sternite VII, left and right laterotergite VIII, and parameres. In addition, a pair of dorsal abdominal gland scars are present in C. pavelstysi , but not in C. miyamotoi .

Description. Male. Body elongate-oval, small (1.4–1.7 mm).

Coloration ( Figs 5–6 , 30 ). Head reddish-brown to darker orange brown; eyes and ocelli dark red; antennae pale yellow to brown; labium pale yellow. Pronotum reddish-brown to darker orange brown, with posterior angles widely darkened, sometimes darkened along posterior margin. Scutellum reddish-brown to darker orange brown. Forewings smoky dark brown, with 2 obscure paler markings on area between costal fracture and claval fracture. 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 5, 7 ), with 5–6 pairs of very long erect setae on each side of clypeus, inner side of antennal insertion, and 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 5, 7 ); segments III and IV sparsely covered with mix of short and longer setae, of which longest much longer than twice width of corresponding segment ( Figs 5, 7 ). 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 ( Figs 20–22 ); left laterotergite VIII basally with sparse short setae ( Figs 20–21, 23 ); right laterotergite VIII basally with distinctive longer setae ( Figs 20, 24 ); sternite VIII and pygophore densely covered with mix of short and longer setae ( Figs 20–21 ); left paramere with 4–5 longer stout setae on anterior extension, basal process with row of very short setae on outer margin, apical process with 6 short setae on middle part ( Figs 25–26 ); right paramere with row of very short setae on outermost margin ( Fig. 27 ).

Structure. Head triangularly produced anteriorly with round apex ( Figs 5, 7 ); head width across eyes approximately 1.6 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 approximately 1.3 times longer than segment IV. Labium reaching posterior part of prosternum; segment I wider than other segments, slightly longer than width; segment III approximately 1.6 times longer than segment II; segment IV slightly longer than segment II. Thorax: pronotum trapezoidal in dorsal view ( Figs 5, 7 ), approximately 0.53 times basal width of pronotum 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, of which fore femora rather thickened; fore tibiae thickened toward apex, 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, spine shorter than maximum width of mid tibiae; 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 tibiae; tarsal formula 3-3-3. Forewing surpassing apex of abdomen; marginal vein loop cut by costal fracture; venation as shown in Fig 10 . 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 20–21 ); mediotergite II–VI a little narrowed dextrally ( Fig. 20 ); pair of dorsal abdominal gland scars present near posterior margin of mediotergite III; posterior margin of mediotergite VII concave medially ( Fig. 20 ); left laterotergites present on IV, V, and VII (not divided into dorsal and ventral laterotergites), left laterotergites VI fused with sternite ( Figs 20–21 ); left side of sternite VII spatulate, apically truncated, with small process on posterior angle ( Fig. 22 ); spiracles located on laterotergites IV–VII (on left side, located on laterotergite IV–VI and sternite VII), and subbasally on left laterotergite VIII ( Figs 20–23 ). Genitalia: mediotergite VIII asymmetrical, complicatedly shaped, with distinctive dorsally elevated projection on left side ( Fig. 20 ); left laterotergite VIII falcate, medially with triangular flange ( Figs 20, 23 ); right laterotergite VIII very large, flattened, U-shaped with large anterior process and slightly shorter posterior process, large anterior process knife-shaped, posterior process almost as wide as anterior process and tapering apicad ( Figs 20, 24 ); sternite VIII very large, asymmetrical, narrowed dextrally in ventral view. Pygophore large and oval, maximum length approximately as long as that of sternite VIII, anterodorsally with ridges and process (anterodorsal projection) ( Figs 20–21 ); anterodorsal projection very large, with large dorsally elevated process and spatulate process ( Figs 20–21 ); left paramere elongate, longer than left laterotergite VIII, with two basal extensions and apical process, two basal extensions present with distinct anterior extension and large basal process, apical process slender and sinuate, apically curved inwardly ( Figs 20–21, 25–26 ); right paramere short and flattened, with two distinct lobes, large rounded lobe and smaller angulate lobe ( Figs 20, 27 ).

Female ( Figs 7–8 , 28 ). Similar to male in coloration, surface, and vestiture, slightly smaller than male, rather ovoid; tarsal formula 2-2-3; forewing sometimes not surpassing apex of abdomen; abdomen symmetrical. Genitalia: spermatheca as shown in Fig 28 ; 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 but longer than that of C. miyamotoi .

Measurements (♁ n = 10 / ♀ n = 10, holotype in parentheses). Body length 1.44–1.69 (1.63) / 1.43–1.59; head width across eyes 0.29–0.33 (0.32) / 0.31–0.34; interocular distance 0.16–0.22 (0.19) / 0.19–0.22; length of antennal segments I – 0.04–0.06 (0.05) / 0.04–0.06, II – 0.11–0.13 (0.13) / 0.11–0.13, III – 0.39–0.43 (0.40) / 0.38–0.40, and IV – 0.27–0.32 (0.30) / 0.28–0.30; length of labial segments II – 0.06–0.09 (0.08) / 0.06–0.08, III – 0.11–0.13 (0.12) / 0.12–0.14, and IV – 0.08–0.10 (0.10) / 0.08–0.10; length of pronotum along meson 0.20–0.25 (0.23) / 0.23–0.25; width of pronotum 0.39–0.45 (0.43) / 0.39–0.45; length of forewing 1.04–1.25 (1.15) / 0.99–1.13; length of hind tibiae 0.42–0.47 (0.46) / 0.42–0.45.

Etymology. Dedicated to the late Dr. P. Štys, one of the world’s leading heteropterists and author of many seminal papers on Dipsocoromorpha , who regretfully passed away in August 2018.

Distribution. Japan (Ryukyus: Ishigaki-jima Is.).

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 20‒28. Morphological details of Cryptostemma pavelstysi sp. nov., male (20‒27) and female (28). 20‒21 – abdomen, dorsal (20) and lateral (21) views; 22 – left side of sternite VII, laterodorsal view; 23 – left laterotergite VIII, laterodorsal view; 24 – right laterotergite VIII, laterodorsal view; 25‒26 – left paramere, dorsal and anterior views; 27 – right paramere, dorsal view; 28 – spermatheca.Abbreviations: adpp = anterodorsal projection of pygophore; an = anophore; app = apical process of paramere; bpp = basal process of paramere; dag = dorsal abdominal gland scars; g = spermathecal gland; lp = left paramere; lt4–8 = laterotergite IV–VIII; mt8 = mediotergite VIII; py = pygophore; rp = right paramere; sc = seminal capsule; st4, 5, 7, 8 = sternite IV, V, VII, VIII. Scale bars = 0.2 mm for 20‒21; 0.1 mm for 22‒27; 0.05 mm for 28.

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.