Nacolus tuberculatus ( Walker 1858 )

Tang, Jiu & Zhang, Yalin, 2019, Review of the oar-head leafhopper genus Nacolus Jacobi (Hemiptera: Cicadellidae: Hylicinae), Zootaxa 4571 (1) : -

Nacolus tuberculatus ( Walker 1858)

( Figs. 1–51 )

Prolepta (?) tuberculata Walker 1858: 315 ; Oshanin 1912:114.

Uangama tuberculata (Walker) Distant 1912: 446 ; Metcalf 1962: 13.

Nacolus gavialis Jacobi, 1914: 381 ; Schumacher 1915: 97; Jacobi 1944: 35; Evans 1946: 47; Esaki and Ito 1954: 27; Metcalf 1962: 12. syn. n.

Ahenobarbus assamensis Distant 1918: 28 ; Kato 1928: 227; Kato 1928: 227; Ouchi 1938: 28; Jacobi 1944: 35.

Ahenobarbus tuberculatus (Walker) , Distant 1918: 28; Evans 1946: 46.

Mellia granulata Schmidt, 1920b: 128 ; Jacobi 1944: 35; Metcalf 1962: 17.

Melliola granulata Schmidt, Evans 1946: 47 ; Metcalf 1962: 17. syn. n.

Ahenobarbus sinensis Ouchi 1938: 27 ; Metcalf 1962: 12.

Nacolus sinensis (Ouchi) , Metcalf 1962: 12. syn. n.

Nacolus assamensis (Distant) , Esaki and Ito 1945: 27; Metcalf 1962: 12. syn. n.

Nacolus tuberculatus Walker, 1858: 315 ; Metcalf 1962: 13.

Nacolus fuscovittatus Kuoh 1992: 285 . syn. n.

Nacolus nigrovittatus Kuoh 1992: 286 . syn. n.

Length (including forewing): ♂ 11.3–16.5 mm, ♀ 13.9–19.8 mm.

External morphology. Body longer than wings. Median longitudinal carina and base of crown, apex of anteclypeus, pronotum region between two lateral ridges and exposed part of mesonotum and scutellum deep brown or black, remaining parts yellow brown to dark. Crown ( Figs. 1, 3 , 12, 14 , 22 , 23 , 27–31, 37–43 ) oar-shaped in lateral view and triangular shape in dorsal view, terminal half intermediately compressed and elevated and with several tubercles on sides, apex obliquely truncate in lateral view, one pair of bilateral tubercles located on base of compressed part, distance between eye and ocellus shorter than diameter of ocellus. Face ( Figs. 2 , 13 , 32–36 ) with antennal ridges not very well developed, curved, not concealing antennal base in anterior view, frontoclypeus about as long as 3.0–4.0x anteclypeus and with many scattered tubercles and with longitudinal ridge at apex, clypeal sulcus can be observed, anteclypeus convex but concave in middle and gradually narrowed apically in profile, lorum with lateral margin dorsal end even with clypeal sulcus. Pronotum ( Figs. 1, 3 , 12, 14 , 22 , 23 , 27–31, 37–43 ) with three longitudinal ridges and with (or not) several longitudinal setae belts on dorsal surface, median ridge almost connected with median ridge of crown, anterolateral region sunken, lateral surface narrowed downward and concealing most of mesepisternum. Exposed part of mesonotum and scutellum ( Fig. 5 ) with anterolateral regions of mesonotum slightly protuberant, posterolateral regions of mesonotum forming small tubercles, scutellum swollen distad of scutoscutellar sulcus in lateral view and attenuated in dorsal view, extreme posterior point usually paler than rest. Forewing ( Fig. 4 ) with veins R, M fused basally, vein RA1 absent, veins Pcu and A1 separated from each other, central anteapical cell slightly longer than another two, four apical cells, 1st apical cell usually longest, appendix well developed, extending around wing apex from claval suture to 4th apical cell. Hind femur macrosetal formula 2+0+0, tibia row AD with spine-like setal bases, with ca. 10, 9 setae in rows AD, PD respectively.

Male genitalia. ( Figs. 7–11 , 17–21 , 24–26 ) Pygofer ( Figs. 7 , 17, 18 , 24 (A–E)) with thumb-shaped ventral appendages partly separated from base by membrane and extended on inner surface of lobe, distal half of ventral appendages with more or less long setae. Subgenital plate ( Figs. 9 , 19 , 24 (A1-3–F)) with gracile setae surrounding lateral margins on inner surface. Connective ( Figs. 10, 11 , 20, 21 , 25 , 26 ) with vertical process usually appressed to each other but divergent at apex in dorsal view, apex of vertical process backward curved and gradually acute. Style ( Figs. 10, 11 , 20, 21 , 25 , 26 ) usually longer than connective, apophysis stretched ventralward and with about five to twenty setae on apex. Aedeagus ( Figs. 10, 11 , 20, 21 , 25 , 26 ) with dorsal surface generally concave except for apex, median keeled, preatrium developed and swollen ventrally, gonopore at apex.

Female. Tergite VIII ( Fig. 46 ) with one pair of big and one pair of small rearward extending protuberances, sternite VII ( Fig. 44 ) overlapping base of ovipositor. Pygofer ( Fig. 45 ) with many scales on surface. Second valvulae ( Figs. 48, 49 ) narrow at basal half, broadened in distal half, base of distal half with about ten small teeth on dorsal margin, apical half of distal half with many ducts on dorsal margin, ventral margin convex and apex narrowly acute with several ducts.

Material examined. Types: Nacolus tuberculatus (Walker) Holotype ♀: ‘ Prolepta ? Tuberculata, Type’ (BMNH); Nacolus gavialis Jacobi syn. n. 2♂ Syntypes: 1♂ (here be used to take photos): Formosa, 1909, H. Sauter; 1♂: Formosa, 1911, H. Sauter ( SMTD) ; Nacolus assamensis (Distant) syn. n. Holotype ♀: Assam, 1911, Distant ( BMNH) ; Melliola granulata Schmidt syn. n. Holotype ♂: Tsha-jiu-san, China, 1910-VIII, S. V. Mell ( ZMB) ; Nacolus fuscovittatus Kuoh syn. n. Holotype ♀: Moxi, Luding, Sichuan Province, China, 1600m, 1983- VI-19, Yuanqing Chen; 1♀ Paratype: Desheng, Luding, Sichuan Province, China, 1230m, 1983-VI-21, Shuyong Wang ( IZCAS) ; Nacolus nigrovittatus Kuoh syn. n. Holotype ♀: Menghai County, Yunnan Province, 1100m, 1982-IV-17, Shengqiao Jiang ( IZCAS) .

Additional specimens: 10♂ 4♀: Louguantai , Shaanxi, China, 1991-IX ( NWAFU) ; 1♂: Tianping Mountain , Longsheng County, Guangxi Province , China, 1946-VIII-26, Genchen Wang ( TMNH) ; 1♂: Taibai Mountain , Shaanxi, China, 1200m, 1982-IX-18 ( NWAFU) ; 1♂: Mountain Taibai , Shaanxi, China, 1982-X-7 ( NWAFU) ; 1♂: Taibai Mountain , Shaanxi, China, 1981-VIII-14 ( NWAFU) ; 1♂: Wanhsien , Sichuan Province, China, 1200m, 1994-IX-28, Fasheng Li ( CAU) ; 1♂: Yifeng County, Jiangxi Province, China, 1985-X-25, Shengchang Hu ( NWAFU) ; 2♂: Dayong County, Hunan Province, China, 1978-VIII-27, Xinwang Dong ( NWAFU) ; 1♂: Tianmu Moutain , Zhejiang Province, China, 1953-IX-20 ( SEM) ; 4♀: Fang County, Hubei Province, China, 1977-VI, Shengli Liu ( NWAFU) ; 2♀: Shennongjia , Hubei Province, China, 1977-VII-15, Shengli Liu ( NWAFU) ; 2♀: Raizan County, Guizhou Province, China, 1985-V-12, Zizhong Li ( NWAFU) ; 2♀: Yudu County, Jiangxi Province, China, 1978-V-5, Jikun Yang ( CAU) ; 2♀: Tianmu Mountain , Zhejiang Province, China, 1957-VII-1 ( CAU) .

Distribution. China (Anhwei, Beijing, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Taiwan, Yunnan, Zhejiang), India (Assam), Japan.

Remarks. In the original papers ( Walker, 1858; Distant, 1912; Schmidt, 1920b), the type specimens of Nacolus tuberculatus (Walker) , Nacolus assamensis (Distant) and Melliola granulata Schmidt were each referred to as “type” so we presume there was only one specimen for each species and interpret these specimens as holotypes. Moreover, only one specimen labeled "Type" of each species was found among material in the BMNH. According to the original publication, syntypes of Nacolus sinensis (Ouchi) were deposited in the Shanghai Science Institute, Shanghai, China ( Ouchi, 1938). We could not find the type series either in the Shanghai Entomological Museum or the Institute of Zoology of Chinese Academy of Sciences as mentioned in the original paper, so the specimens appear to have been lost. We propose the synonymy of Nacolus sinensis (Ouchi) with Nacolus tuberculatus ( Walker 1858) based on the original description and study of additional specimens from the type locality, Tianmu Mountain.

After comparative study of many specimens, we found that the shape and proportions of the head, the coloration of the body and development of brown longitudinal bands on the wings vary considerably among individuals collected in both sympatric and allopatric populations. Thus, we consider the differences in these characteristics to represent intraspecific rather than interspecific variation. The structure of the male genitalia is basically consistent with minor differences among individuals, even those which are very similar in external morphology. On the other hand, many individuals with similar genitalia are very different in external appearance. Because we were unable to find distinct discontinuities in both genitalia and external morphology among groups of specimens examined, we interpret all specimens examined to belong to a single widespread and variable species. The shape of the second valvulae, which are obviously different between two species of another Hylicinae genus, Hylica Stål ( Tang and Zhang, 2018) , are very consistent among females of Nacolus .

Although Nacolus gavialis was the name of the type species of this genus, Nacolus tuberculatus is the oldest available name among all these species names. So we propose to use Nacolus tuberculatus as the valid name of this species instead of Nacolus gavialis .

Figures

FIGURE 22. Nacolus tuberculatus (Walker 1858), male. Variation in habitus, dorsal view. Different letters refer to different localities.

FIGURE 23. Nacolus tuberculatus (Walker 1858), male. Variation in head, lateral view. Different letters refer to different localities.

FIGURE 24. Nacolus tuberculatus (Walker 1858), male. A–E. Variation in pygofer, ventral view; A1-3–F. Variation in subgenital plate, dorsal view. Different letters refer to different localities.

FIGURE 25. Nacolus tuberculatus (Walker 1858), male. Variation in aedeagus, connective and style, dorsal view. Different letters refer to different localities.

FIGURE 26. Nacolus tuberculatus (Walker 1858), male. Variation in aedeagus, connective and style, lateral view. Different letters refer to different localities.

FIGURES 1–11. Nacolus gavialis Jacobi 1914 syn. n., Type ♂: 1. Habitus, dorsal view; 2. Face; 3. Head and pronotum, lateral view; 4. Forewing and hind wing; 5. Exposed part of mesonotum and scutellum, dorsal view; 6. Segment VIII, ventral view; 7. Pygofer, ventral view; 8. Anal tube, ventral view; 9. Subgenital plate, dorsal view; 10. Aedeagus, connective and style, dorsal view; 11. Aedeagus, connective and style, lateral view.

FIGURES 12–21. Melliola granulata Schmidt 1920 syn. n., Holotype ♂: 12. Head and pronotum, dorsal view; 13. Face; 14. Head and pronotum, lateral view; 15. Abdomen, dorsal view; 16. Abdomen, ventral view; 17. Pygofer, ventral view; 18. Pygofer, lateral view; 19. Subgenital plate, dorsal view; 20. Aedeagus, connective and style, dorsal view; 21. Aedeagus, connective and style, lateral view.

FIGURES 27–41. 27, 32, 37. Nacolus tuberculatus (Walker 1858), Holotype ♀; 28, 33, 38. Nacolus assamensis (Distant 1918) syn. n., Holotype ♀; 29, 34, 39. Nacolus fuscovittatus Kuoh 1992 syn. n., Holotype ♀; 30, 35, 40. Nacolus nigrovittatus Kuoh 1992 syn. n., Holotype ♀; 31, 36, 41. Nacolus sinensis (Ouchi 1938) syn. n., ♀: 27. Head and pronotum, dorsal view; 28–31. Habitus, dorsal view; 32–36. Face; 37–41. Head and pronotum, lateral view.

FIGURE 42. Nacolus tuberculatus (Walker 1858), female. Variation in habitus, dorsal view. Different letters refer to different localities.

FIGURE 43. Nacolus tuberculatus (Walker 1858), female. Variation in head, lateral view. Different letters refer to different localities.

FIGURES 44–51. Nacolus tuberculatus (Walker 1858), female. 44. Sternite VII, ventral view; 45. Pygofer, ventral view; 46. Sternite VII, Segment VIII and Pygofer, dorsal view; 47. First valvula; 48. Second valvulae; 49. Distal half of second valvulae; 50. Second valvifer; 51. Third valvula.