Acothrura impunctata ( Jacobi, 1905 )

Liu, Yidi, Ren, Yujie & Wang, Menglin, 2024, Sexual dimorphism in the genus Acothrura Melichar, 1915 (Hemiptera: Lophopidae) and description of male and female specimens of A. impunctata (Jacobi, 1905), Zootaxa 5447 (2), pp. 225-238 : 226-234

Acothrura impunctata ( Jacobi, 1905) ( Figs 1–44 )

Corethrura impunctata Jacobi, 1905: 438 .

Acothrura impunctata ( Jacobi, 1905) : Melichar, 1915: 353.

Description

Note. Sexual dimorphism occurs in this species. The most obvious differences between male and female are in the size, coloration and band patterns on the tegmina, as well as in leg coloration.

General appearance

♂ Body length including tegmina: 11.9–13.5 mm. ♀ Body length including tegmina: 15.3–15.6 mm.

Head. Vertex ( Figs 1, 3 , 15, 16 ) light brown, trapezoid, around 2.2 times wider for width at base than length in midline; anterior margin nearly straight, slightly shorter (around 0.7 times) than posterior margin; lateral margins sinuate, expanded below upper margin of compound eyes; posterior margin roundly concave; median carina present well; disc with two black semilunar spots at base adjoining the posterior margin. Frons in dorsal view ( Figs 3 , 16 ) protruded in front of vertex, around 0.5 times longer than vertex. Frons in ventral view ( Figs 4 , 17 ) tulip shaped, tawny, obviously longer than wide, around 1.4 times longer in midline than widest part, around 0.7 times wider in anterior margin than posterior margin; apical margin straight, lateral margins subparallel in upper half and expanded outward in basal 1/4; median carina well present, but not obvious in upper 1/3; sublateral carinae obviously ridged and fused in the apex to an inverted “V” shape; frontal disc with a large transverse black patch at middle crossing median carina, two oblique black bands on basal 1/4, and two transverse black bands near base; surrounding between sublateral carinae and lateral margins, the area distributed with several irregular black markings on each side from apical margin to near base, markings on apical 1/3 crisscrossed, then three transverse markings independent, and finally two large bands on basal 1/3. Frontoclypeal suture ( Figs 4 , 17 ) nearly straight. Lateral ocelli red ( Figs 2 , 19 ). Compound eyes rounded and black ( Figs 1–4 , 15–19 ). Antennae ( Figs 3–4 , 16–17 ) with short scape, cylindrical pedicel and linear flagella, apex of scape and base of pedicel black. Clypeus ( Figs 4 , 17 ) tawny, inverted triangular, around 1.4 times longer in midline than widest part, with one short and one long black longitudinal stripes arranged up and down on each side of median carina. Labium ( Figs 4 , 17 ) tawny, reaching to metatrochanters, apical segment less than half length of basal segment.

Thorax. Pronotum ( Figs 3 , 16 ) tawny, triangular, around 4.8 times wider at widest part than length at middle, tricarinate; with two small round black spots on each side of median carina near anterior margin, and four black longitudinal bands on each side of lateral area; anterior margin roundly protruded forward at middle; posterior margin almost straight. Mesonotum ( Figs 3 , 16 ) tawny, large and inverted triangular, around 0.6 times longer in midline than widest part, tricarinate; with two black round spots on each side between median carina and lateral carinae, respectively close to anterior margin and to posterior margin, and five to seven black spots respectively on each side in lateral area; posterior apex sharp.

Legs. Fore and middle femur with two regular rows of black linear dots along its length in dorsal view ( Figs 1 , 15 ) and one row in ventral view ( Fig. 17 ). Fore tibia slightly foliated. Fore and middle tibia ( Figs 4 , 17 ) with some black ring belts and rows of small black dots along its length. Hind tibia ( Figs 7 , 20, 21 ) with three lateral spines and numerous small apical spines. Hind tarsus ( Figs 7 , 20 ) with a pad of microsetae on first segment.

Sexual dimorphism. Male with size slightly shorter than female. After soaked in alcohol, male ( Figs 1–2, 4 ) with tegmina dark yellowish brown, irregular interspersed with numerous round black spots, with three broad transverse black bands respectively at basal 1/3, at middle and at apical 1/3, the basal and apical bands somewhat straight, middle band sinuate, apex of tegmina black but not always well visible in some specimens; all legs tawny. Female ( Figs 15, 18 ) with tegmina reddish brown, irregular interspersed with numerous round black spots but without black bands on surface; fore and middle legs ( Figs 17, 18 ) light red, only hind legs ( Figs 20–21 ) reddish tawny. In nature, male ( Fig. 43 ) with tegmina greyish white, the transverse bands and the round small spots brown, legs greyish white; female ( Fig. 44 ) with tegmina reddish brown, spots black, frons somewhat green, fore and middle legs light red.

Male genitalia. Anal tube ( Figs 5, 8 ) with apical half slightly expanded and bending down in lateral view, apex truncated; in dorsal view cylindrical, obviously longer than wide, about 2.1 times longer for length in midline than width in midline; apical margin triangularly concave at middle, dorso-lateral angles rounded; anal pore located slightly above middle. Pygofer ( Fig. 5 ) rectangular, longer than wide in lateral view; dorsal margin longer than ventral margin, dorsal margin inclined downward, dorso-lateral angle obtusely protruded posterior; posterior margin sinuate, concave anteriorly in apical half, then straight in basal half, baso-ventral process obvious; ventral margin straight. Gonostyli ( Fig. 5 ) with dorsal margin regularly upward then obviously concave at basal 1/3 forming two obvious and separate round lobes; basal lobe bearing a triangular process oriented ventrad near dorsal margin; ventral and posterior margins of gonostyli regularly curved. Periandrium ( Figs 9–14 ) with dorsal margin elevated on both side forming to a sack, nearly straight at middle, then fused to a sclerotized finger-shaped process directing upward to dorso-posterior in apex in lateral view; with a pair of strongly sclerotized needle-shaped processes directing to apex in apical 1/4 of ventral margin and a pair of auriform processes in apical 1/3. Aedeagus ( Figs 9–11 ) with a pair of long ventral posterior processes derived from apical 1/3, curved upward, then directed dorsally in lateral view; apex of aedeagus rounded in lateral view.

Female genitalia. Anal tube ( Figs 22–24, 28–29 ) strongly curved downward nearly at half length in lateral view, with a pair of large oval lobes in apical part; anal pore located in basal half. Gonoplacs ( Figs 25–26 ) hirsute, in lateral view higher than wide, dorsal part narrower than ventral part, posterior margin nearly straight; in ventral view triangular. Gonapophysis IX ( Fig. 26 ) small and reduced, triangular. Gonocoxae VIII ( Figs 27–28 ) developed, with dorsal margin nearly straight at middle but lateral sides curved upward to sharp angles directing to dorsad. Gonapophysis VIII ( Figs 27–28 ) small and reduced, triangular, fused at middle. Sternite VII ( Figs 27–28 ) with a strongly sclerotized “ M ” shaped protrusion in middle of dorsal margin. Bursa copulatrix ( Figs 29–30 ) large, ball shaped with white ornamentations, connected to posterior vagina by a short ductus. Anterior vagina ( Figs 29–30 ) broad and developed, connected to a long spermatheca ( Figs 29–30 ). Sclerotized plate ( Figs 29–30 ) developed.

Distribution. Vietnam; China (Yunnan, Guangxi).

Biology. The specimens were collected from a bamboo forest adjacent to river ( Figs 45–46 ). This species habitats on the stem and leaves of bamboo ( Poaceae ) ( Figs 43–44 ).

Material examined. 1♀ (Holotype), Chiem-Hoa, Central-Tonkin, Vietnam,Aug.–Sept., H. Fruhstorfer (checked by photos); 7♂♂ 7♀♀, Qichong natural reserve, Zhaoping County, Hezhou City, Guangxi Province, China, N 24º 16´55´´, E 110º 50´18´´, Alt. 200m, 1 viii 2022, Liu YD & Deng KY.

Remarks. The difference in the partial part of COI gene sequences between a male (GenBank number on NCBI: OR667024) and a female (GenBank number on NCBI: OR667025) of this species is just around 2 bp from the length of 713 bp, confirming that the two specimens are conspecific and depicting the sexual dimorphism of the species.

Figures

FIGURES 1–14. Acothrura impunctata, male. 1. Adult, dorsal view; 2. Adult, lateral view; 3. Head and thorax, dorsal view; 4. Frons and clypeus, ventral view; 5. Genitalia, lateral view; 6. Genitalia, ventral view; 7. Hind legs; 8. Anal tube, dorsal view; 9. Phallic complex, left lateral view; 10. Phallic complex, right dorso-lateral view; 11. Phallic complex, left dorso-lateral view; 12. Phallic complex, dorso-caudal view; 13. Phallic complex, dorsal view; 14. Phallic complex, ventral view. Scale bars: 1–4, 7=1 mm; 5, 6, 8–14=0.2 mm.

FIGURES 15–21. Acothrura impunctata, female. 15. Adult, dorsal view; 16. Head and thorax, dorsal view; 17. Frons and clypeus, ventral view; 18. Adult, lateral view; 19. Head and thorax, lateral view; 20–21. Hind leg. Scale bars=1 mm.

FIGURES 22–28. Acothrura impunctata, female genitalia. 22. Anal tube, dorsal view; 23. Anal tube, ventral view; 24. Anal tube, lateral view; 25. Gonoplacs and gonapophyses IX, lateral view; 26. Gonoplacs and gonapophyses IX, caudal view; 27. Gonapophyses VIII, gonocoxae VIII and sternite VII, ventral view; 28. Genitalia, ventral view. Scale bars=0.2 mm.

FIGURES 29–30. Acothrura impunctata, female genitalia including internal reproductive system, lateral view. Scale bars=0.2 mm.

FIGURES 31–36. Acothrura impunctata, holotype. 31. Adult, dorsal view; 32. Type labels; 33. Head and thorax, lateral view; 34. Head and thorax, dorsal view; 35–36. Frons and clypeus.

FIGURES 37–42. Acothrura impunctata, holotype. 37. Right tegmina and wing; 38. Left wing; 39. Apex of hind tibia and tarsus; 40–42. Apex of abdomen.

FIGURES 43–44. Habitat of Acothrura impunctata in nature. 43. Male; 44. Females.

FIGURES 45–46. Habitat of Acothrura impunctata in Qichong natural reserve, Guangxi, China.