Euscyrtus japonicus Shiraki, 1930

Yang, Jeng-Tze & Yang, Ching-Shan, 2012, The slim mute crickets, Euscyrtinae (Orthoptera: Grylloidea; Gryllidae; Euscyrtinae) of Taiwan with three new species and lectotype designations of three of Shiraki’s species, Zootaxa 3226, pp. 1-45 : 8-12

Euscyrtus japonicus Shiraki, 1930

( Fig.4 , 5 , & 6)

Euscyrtus japonicus Shiraki, 1930 . Ins. Matsum. 4: 245. Chopard, 1968. Orth. Cat. 12: 420.

Coloration. Body brown with reddish brown lateral stripes, from head through eyes to tip of tegmen, without sublateral stripe; vertex with 3 pairs of brown stripes, outer ones light brown stripes, sub-lateral ones broad band dark reddish brown, middle ones marked. Lateral view, eyes dark in middle, upper part brown and yellow banded, lower part in various color, arranged in layers: yellow, black, yellow, brown. Pronotum brown, lateral areas dark brown along with middle line; tear like marks surrounding with dark reddish brown. Dorsal surface of hind femur marked with brown.

External morphology. Head almost round in dorsal view, lateral margins slightly expanded laterally behind eyes, width at level of eyes a little wider than wide of head about 1.1: 1; head shorter than widest wide about 1: 1.1. Frontal rostrum very long, apical margin straight, produced anteriorly; middle ocellus elliptical, on apical point of frontal rostrum; head wider than widest part of frons and wider than frontal rostrum about 9.8: 6.0: 1.0. Eyes almond like, protruding on lateral margins of vertex; eyes longer than wide about 1.5: 1, eyes shorter than head in middle long about 1:2.5; antennal scape elongate, longer than wide about 12: 1, about 0.3 times as long as head; Head longer than pronotum about 1.3:1, head as wide as pronotum at anterior margin; anterior margin of pronotum as wide as posterior. Head in lateral view triangular, dorsal surface arched, frons reclined caudo-ventrade; superior margin of antennal socket shorter than diameter of eyes about 1: 1.5; posterior margin of antennal socket foliate, directed anteriorly, anterior margin sinuate. Maxillary lacinia acute, inner margin curved; maxillary palpi 5-segmented, 1st:2nd: 3rd =1:1.2:1; labial palpi 3-segmented, 1st:2nd: 3rd = 1:1:2.3.

Head in anterior view polygonal; frons shorter than remainder of face, about 1: 2, as long as mouth part; lateral margins of frons divergent ventrally; width of frons narrower at narrowest than at widest part of the level of lateral process of frons about 1: 5.6; lateral process of frons acute at apex reach at joint of antennal socket and eyes. Upper margin of mouth part arched upward slowly. Clypeus middle line shorter than widest part about 1:1.7; shape formula of moth part, width of post clypeus/ ante-clypeus/ labrum about 1.8:1:1.8.

Pronotum dorsal view anterior margin slightly curved inward; posterior margin bi-sinuate, arched posteriorly at middle; lateral margins formed caudo-lateral angles. Pronotal disc with anterior part sub-equals to posterior part; middle line shorter than length at lateral margins about 1:1.1; shorter than anterior wide about 1: 1.4. Pronotal lateral lobes straight on dorsal margin, anterior running into ventral margin roundly then slowly upward dorsally; dorsal length of pronotum longer than width of widest part about 1.2: 1. Metanotum without metanotal gland, without middle transverse prominent; anterior margin slightly curved inward, middle long shorter than width at widest part about 1:1.4. Tegmen longer than wide, about 1.8: 1, about 1/3.7 of body length, apex reaching at abdominal segment III; Veins parallel in lateral area, irregular in dorsal area, without stridulate organ. Fore-tibia without tympanum on outer side; 1st tarsal segment with sac like pulvillus white, 3rd segment with pulvillus large and expanded; 3 tarsi about 1:1.1:1.1; inner margin of claws with spine near apex. Hind femur obviously exceeding abdominal apex, femur equal to tibia; lateral spines of hind tibia i/o = 9/8, inner side 2 groups, spines and (intercalary)= 9 (1)1, 4 basal teeth, outer side 7 group, spines and (intercalary)= 2 (1)1(2)1(2)1(2) 1(2) 1(2)1, 12 basal teeth.

Male genitalia. In dorsal view, epiphallus subtriangular, 2 ear-like processes at joint between epiphallus and cornua, epiphallus with posterior margin produced at middle, epiphallus shorter than width at widest part at middle line about 1:1.1; epiphallus about 3.3 times longer than cornua, cornua with apical lateral lobes curved ventrally; cornua digitate, apex with joint point, middle long about 3.1 times longer than widest part; ventral area invisible, about 1/6.7 of male genitalia. Lateral view, epiphallus and cornua formed triangular, ear-like processed directed dorsally; cornua obtusely round at apex; rami reaching at middle of epiphallus, ectoparamere not exposed. Ventrally, cornua digitate, dorsal area visible; ectoparamere minute, elliptical, about 3.7 times as long as widest width, reaching at base of cornua; median lobe exceeding over apex of ectoparamere. Subgenital plate sub-triangular in dorsal view, acute at apex, longer than widest part about 1.7: 1, lateral margins curved inward, curved part about 1/ 1.8 of the length of subgenital plate.

Female genitalia. Ovipositor equal to body length, about 1:1; curved upward at half, sword portion expanding ventrally, about 1/2.7 as long as length of ovipositor. Cross section wider than height about 1.6: 1.

Type materials. Lectotype: (here designate) male, “ Euscirtus japonicus nsp”; “ E. hemelytrus, Det. T. Shiraki ”; “ Type ”; “832”.

Paratype: female, “ Euscirtus japonicus nsp”; “ E. hemelytrus, Det. T. Shiraki ”; “Nakano, VIII, col. T. Okuni”; “ Type ”; “831”.Notes: Specimen No. 832 lost right lateral legs.

Types deposited in NTUIM: Insect Museum, Department of Plant Pathology and Entomology, National Taiwan University, Taipei, Taiwan.

Habitat. old growth forest, moist ground vegetation.

Host plant. Axonopus compressus , Miscanthus sp.

Male 1

Body length 11.44

Head length 1.85

Head width 1.95

Pronotum length 1.46

Pronotum width 1.86

Fore-wing length 2.28

Fore-femur length 1.64

Fore-tibia length 1.60

Hind-femur length 7.43

Hind-femur width 1.56

Characters n Min. (mm) Max. (mm) Mean ± SD (mm) CV (%) Female 3

Body length 10.29 11.50 11.02 ± 0.64 5.81 Ovipositor length 9.73 10.66 10.13 ± 0.47 4.64 Specimens examined. Taipei: TaiRd#2, 10 Km, 1 female (681-1), 24-VII-1996, CS Yang. TaipeRd #6, Tung Hsing Chemical Factory, 1 female (684-3), 25-VII-1996, CS Yang. Taichung county: 1 female (793-2), 4-V-1997, CS Yang. Pingtung: LiDeTzu hei garden, 2 male (711-8, 711-9), 1 female (711-12), 10-IX-1996, CS Yang. 1 female (772-2), 1-IV-1997, CS Yang. 1 male (776-2), 2-IV-1997, CS Yang.

Distribution. Taiwan (new record), Japan, Korea.

Figures

FIGURE 4. Euscyrtus japonicus. A: head and pronotum, dorsal view; B: the same, lateral view; C: head, anterior view; D: metanotum, dorsal view; E: labium, ventral view; F: maxilla, lateral-ventral view; G: fore leg, inner side; H: fore leg, outer side; I: tarsus of fore leg, ventral view; J: hind tibia, inner side (left), outer side (right); K: fore wing, extended.

FIGURE 5. Euscyrtus japonicus. A, B: male genitalia, dorsal view; C, D: the same, ventral view; E, F: the same, lateral view; G: subgenital plate, dorsal view; H: abdominal terminal of female, lateral view; I: Ovipositor (cross section).