Schiodtella japonica Imura & Ishikawa, 2009, new species
Creators: name: Imura, Jimpei
name: Ishikawa, Tadashi
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Cydnidae
Schiodtella
Schiodtella japonica

description: Schiodtella japonica new species
(Figs. 1–16, 31–36)
Stibaropus formosanus: Hasegawa, 1960: 24, fig. 4; Miyamoto, 1965: 75, pl. 38, fig. 11; Miyamoto and Yasunaga, 1989: 183.
Diagnosis. Eyes moderately small (Figs. 3, 4); ocular index 6.2–8.3. Apical process of peritreme indistinct (Fig. 9). Tarsi present (Figs. 5, 7). Median arm of basal plate of penis surpassing lateral arms (Fig. 10); conjunctival appendage strongly protruding and recurved downwards in rest (Fig. 11). Distal part of spermathecal duct longer than dilation (Fig. 15).
In general appearance, this species resembles Sc. secunda Lis, 1991 from China (Lis 1991b), but it is separable from the latter by its larger eyes (ocular index is 6.2–8.3 in the former, and 10.2–12.8 in the latter) and a more developed conjunctival appendage of the penis (protruding well beyond the phallotreme in the former (Fig. 11), and not externally visible in the latter).
Description. Male: holotype ― total length 4.8; total width 3.2; body 4.4 long, 2.5 high; head 1.0 long, 1.05 wide; length of antennal segments I 0.17, II 0.34, III 0.23, IV 0.33; length of rostral segments I 0.45, II 0.5, III 0.35, IV 0.3; pronotum 1.5 long, 2.64 wide; scutellum 2.14 long, 1.85 wide; hemelytron 3.4 long.
Body castaneous to dark castaneous, darker in dorsum. Eyes red; ocelli orange. Antennae and rostrum yellowish brown to light castaneous. Hemelytral caria slightly lighter than pronotum and scutellum; hemelytral membranes semi-hyaline. Legs light castaneous to castaneous; apical half of protibia blackish; tarsi yellowish brown.
Total length about 1.5 times as long as total width, 1.9 times as long as body height. Head (Figs. 3, 4) moderately wrinkled in dorsum; clypeus (Fig. 3) slightly shorter than paraclypei; paraclypeus (Figs. 3, 4) fringed with 10 or 11 peg-bearing tubercles, ventrally bearing several setae of various length; primary setae III–V (Figs. 3, 4) thickened, longer and slenderer than secondary ones. Eyes and ocelli (Figs. 3, 4) moderately small; ocular index 7.8; ocellar index 5.5; interocellar index 5.0. Setae on antenna thin and dense, but slightly thicker and sparser in segment II; approximate proportion of antennal segments I to IV 1.0: 2.0: 1.4: 2.0. Rostrum reaching mesocoxae; approximate proportion of segments I to IV 1.5: 1.7: 1.2: 1.0. Pronotum (Fig. 1) distinctly wrinkled in posterior half, and with 20–22 setae on lateral margin and 2 setae behind callus (Fig.1), on each side. Scutellum (Fig. 1) evenly wrinkled. Thoracic pleura slightly wrinkled; apical process of peritreme indistinct (Fig. 9). Hemelytron (Fig. 1) moderately developed, surpassing lateral margin and tip of abdomen; corium (Fig. 1) covered with small punctures and wrinkles, bearing 2 rows of small punctures on mesocorium and 1 or 2 rows of them on clavus alongside claval suture, and with 6 or 8 setae on costal margin; clavus (Fig. 1) with 1 seta basally. Protibia (Fig. 14) more or less covered with setae in proximal 4/5 on anterior and ventral sides, and with 5 or 6 spines on tibial edge. Setae on mesotibia (Fig. 6) longer in dorsum and finer in posterior side, gradually becoming stouter toward tibial apex in anterior and dorsal sides. Setae on metatibia (Figs. 7, 8) thinner in posterior side, gradually becoming stouter toward corbicle in anterior and dorsal sides, arranging in 1 rough, longitudinal row on corbicle. Tarsus sparsely covered with fine setae. Abdominal sternites III to VII moderately covered with setae of variable length and thickness. Posteriorly exposed part of terminalia densely covered with setae.
Paratypes ― total length 4.0–4.9; total width 2.8–3.3.
General aspect similar to holotype. Paraclypeus fringed with 7–11 peg-bearing tubercles. Ocular index 6.2–8.3. Lateral margin of pronotum and costal margin of hemelytron with 12–24 and 4–9 setae, respectively. Genital capsule with medial process on apicoventral margin. Penis (Figs. 10, 11) with strongly sclerotized and pigmented theca; median arm of basal plate surpassing lateral arms (Fig. 10); conjunctival appendage strongly protruding from phallotreme and recurved downwards in rest (Fig. 11). Paramere (Fig. 12–14) covered with setae; hypophysis moderately sharpened (Fig. 11).
Female: paratypes ― total length 4.6–5.8; total width 3.1–3.8.
General aspect similar to male. In some specimens hemelytra remarkably developed (Fig. 2) and tarsi also more developed (see below for detail). Setae on mediotergite VIII smaller in medial part (Fig. 16). Paratergite IX (Fig. 16) continuous with gonocoxa II, sharply prominent laterally; gonocoxae II continuously pigmented to each other through midline (Fig. 16). Distal part of spermathecal duct longer than dilation, clearly thinner than proximal part (Fig. 15); flanges of intermediate part larger in diameter than receptacle (Fig. 15).
Type materials. Holotype 3, “Akatsuka-tameike Park, Akatsuka, Itabashi-ku, Tokyo Pref., JAPAN, May 26, 2008, Jimpei IMURA leg.” Paratypes 18326♀ — Japan: Honshu: same locality as holotype: 435♀, 26.V.2008, J. Imura leg. (TUA); 635♀, 21.IV.2008, J. Imura & G. Kaji leg. (TUA); 13, 23.XII.2007, T. Tsurumaki leg. (TUA); Komaba, Tokyo: 13, 1930, R. Sawa leg. (ELKU); Hiratsuka Beach, Kanagawa Pref.: 13, 11.X.1961, N. Watanabe leg. (TUA); 1♀, 28.IX.1958, Y. Shibata leg. (TUA). Kyushu: Kashii, Fukuoka Pref.: 1♀, 25.IX.1959, Y. Hirashima leg. (ELKU); Mt. Aso, 800 m alt.: 2♀, 30.VIII.1958, Fujimura leg. (ELKU); Kusasenrigahama, Aso-shi, Kumamoto Pref.: 5312♀, 14.X.2007, Y. Utsunomiya leg. (OMM).
form sex scutellum hemelytron protarsus mesotarsus metatarsus
form with shortened wings 3 1.97 3.08 0.64 0.38 0.35 3 2.00 3.00 0.52 0.40 0.30 3 2.06 3.28 0.55 0.38 0.32 Ƥ 2.06 3.54 0.65 0.46 0.38 3 2.13 3.30 0.62 0.40 0.35 3 2.15 3.50 0.65 0.40 0.35 Ƥ 2.16 3.54 0.55 0.40 0.36 3 2.17 3.60 0.60 0.40 0.35 3 2.18 3.44 0.52 0.40 0.38 Ƥ 2.18 3.60 0.60 0.45 0.33 Ƥ 2.18 3.76 0.67 0.50 0.43 Ƥ 2.20 3.70 0.60 0.43 0.40 3 2.23 3.40 0.60 0.40 0.38 3 2.25 3.50 – 0.45 0.42 Ƥ 2.36 3.90 0.68 – 0.42
macropterous form Ƥ 2.30 4.45 0.80 0.62 0.55 Ƥ 2.36 4.68 0.78 0.60 0.53 Ƥ 2.38 4.50 0.80 0.60 0.53 Distribution. Japan: Honshu, Kyushu.
Etymology. The name is derived from the type locality.
Remarks. As shown in the synonymy above, this species has previously been known under the name Stibaropus formosanus in Japan (Hasegawa 1960; Miyamoto 1965; Miyamoto & Yasunaga 1989). The species St. formosanus or Schiodtella formosana from mainland China is closely related with or, perhaps, conspecific with Sc. japonica sp. nov., judging from the descriptions provided by Esaki and Ishihara (1951) and Lis (1994). However, a final conclusion about the identity of the Chinese species is on hold until the specimens become available for examination.
The tarsi and the hemelytra, especially their membranes, obviously vary in length among individuals, even among those from a single locality. Table 1 shows the lengths of the tarsi and hemelytra of 18 specimens (nine males and nine females, including the holotype) from one location in Tokyo. Based on the lengths of the hemelytra, the specimens are roughly divided into two types: a form with shortened wings (hemelytral length / scutellar length <1.75), and macropterous form with longer wings (hemelytral length / scutellar length> 1.85); the latter form is shown only in the female. Such a wing dimorphism is also known in the Brazilian Atarsocoris giselleae Carvalho, 1952 (= A. macroptera Becker, 1967) within the tribe Scaptocorini. In addition to the variation of the hemelytra, interestingly, the tarsi, peculiar to those of the hind legs, are also variable in length among the specimens, despite no significant difference in relative body size among the specimens. The shortened tarsus, moreover, accompanies a decrement in the size of the pretarsus (Figs. 31– 36).
Biology. According to Hasegawa (1960), this species lives in soil covered with vegetation, such as upland rice Oryza sativa L., goose-grass Eleusine indica Gaertn and Digitaria ciliaris (Retz.) (Poaceae). In Tokyo, it was also noted that adults are sometimes attracted by artificial light around August and appear on the ground for copulation around October (Hasegawa 1960). Through our field observations in Tokyo, young to old nymphs and adults were found in January 2008 from a soil depth of 10–20 cm under vegetation, such as Penisetum alopecuroides (L.), Imperata cylindrica Beauv., Miscanthus racemosum DC. (Poaceae), and other lower plants.
description: Published as part of Imura, Jimpei & Ishikawa, Tadashi, 2009, A review of Schiodtella formosana, with some remarks on the genus Schiodtella and description of a Japanese new species (Hemiptera: Heteroptera: Cydnidae), pp. 19-30 in Zootaxa 2315 on pages 21-25, DOI: 10.5281/zenodo.192017