Review of the oar-head leafhopper genus Nacolus Jacobi (Hemiptera: Cicadellidae: Hylicinae)
Author
Tang, Jiu
Author
Zhang, Yalin
text
Zootaxa
2019
2019-03-25
4571
1
journal volume
28100
10.11646/zootaxa.4571.1.4
32061d78-2ba5-4885-ab58-7c873ceb45b6
1175-5326
2605952
33538D46-318D-444C-B02A-FC0582CBFDCC
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.
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.
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
)
.
FIGURE 22.
Nacolus tuberculatus
(Walker 1858)
, male. Variation in habitus, dorsal view. Different letters refer to different localities.
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.
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.
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
.