Research Article |
Corresponding author: Xingmin Wang ( wangxmcn@scau.edu.cn ) Academic editor: Yves Bousquet
© 2016 Xiaosheng Chen, Xiufeng Xie, Shunxiang Ren, Xingmin Wang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Chen X, Xie X, Ren S, Wang X (2016) A taxonomic review of the genus Horniolus Weise from China, with description of a new species (Coleoptera, Coccinellidae). ZooKeys 623: 105-123. https://doi.org/10.3897/zookeys.623.10191
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Five species of the genus Horniolus Weise, 1901 from China are revised, including the description of a new species, Horniolus hainanensis Chen & Ren, sp. n. Horniolus sonduongensis Hoàng, 1979 is reported from China for the first time. A key to the species from China is provided. Nomenclatural history, diagnoses, detailed descriptions, illustrations, and distribution for each species have been provided. A checklist of all known species of this genus is also presented.
Coccinelloidea , checklist, Hainan Island, Scymnini , taxonomy
The genus Horniolus was proposed by
Horniolus has been placed in the tribe Scymnini, which was included in the subfamily Scymninae by earlier workers such as
Members of Horniolus mostly prey on mealybugs, such as Planococcus lilacinus Cockerell and Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), infesting coffee, tea and pineapple. These beetles also feed on spiraling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae), and play an important role in the biological control of this pest (
In the present paper, five species of the genus Horniolus from China are revised, with the addition of a new species. All the species are illustrated and described in detail. A key to and distribution map for the species from China are given. A checklist of the species of Horniolus around the world is also provided.
Specimens examined were collected from China and Vietnam, and deposited in the Department of Entomology, South China Agricultural University, Guangzhou, China (SCAU). In addition, the holotypes of H. novempunctatus and H. hisamatsui were obtained from the collection of the Entomological Laboratory, Ehime University, Matsuyama, Japan (ELEU).
The morphological terms follow
TW total width, across both elytra at widest part;
TH total height, at highest part of elytra in lateral view;
TL total length, from apical margin of clypeus to apex of elytra;
PL pronotal length, from the middle of anterior margin to the base of pronotum;
PW pronotal width at widest part;
EW elytral width, equal to TW;
EL elytral length, along suture from base to apex including scutellum;
HW head width, at widest part including eyes.
Male and female genitalia were dissected, cleared in a 10% solution of NaOH by boiling for several minutes, and placed on slides for further study. Photographs of the whole beetles and their genitalia were taken according to
Horniolus Weise, 1901: 442. Type species: Horniolus dispar Weise, 1901, by monotypy.
Horniolus is similar to Scymnus Kugelann, particularly the subgenus Scymnus (Pullus) Mulsant in general appearance. However, it can be easily distinguished from the latter by the following combination of characters: body rounded or elongate oval; antennae composed of 11 antennomeres (Fig.
Body rounded or elongate oval, moderately convex, with dense pubescence, widest around middle of elytra.
Head transverse; frons wide (Fig.
Pronotum moderately convex, hind margin wider than anterior one (Fig.
Bangladesh, China, India, Japan, Malaysia, Nepal, Sri Lanka, Thailand, Vietnam.
1 | Elytra dark brown to black with 4 transverse spots or orange with 6 black spots | 2 |
– | Elytra yellow with 9 black spots (Fig. |
H. novempunctatus Miyatake |
2 | Head and pronotum testaceous; abdominal postcoxal line complete; penis guide shorter than parameres in lateral view | 3 |
– | Head and pronotum black (Figs |
H. hainanensis Chen & Ren, sp. n. |
3 | Pronotum entirely reddish brown; apex of penis expanded with membranous appendage | 4 |
– | Pronotum dark brown with black marking (Fig. |
H. fortunatus (Lewis) |
4 | Body outline narrower; first pair of elytral spots with hind margin deeply emarginated (Fig. |
H. hisamatsui Miyatake |
– | Body outline broader; first pair of elytral spots with anterior margin deeply emarginated (Fig. |
H. sonduongensis Hoàng |
Horniolus
novempunctatus
Miyatake, 1979: 105;
This distinctive species can easily be separated from the other species of Horniolus by its peculiar colour pattern on elytra.
TL: 2.95 mm, TW: 2.00 mm, TH: 1.52 mm, TL/TW: 1.47, PL/PW: 0.51, EL/EW: 1.12, HW/PW: 0.63, PW/EW: 0.86.
Body elongate oval, moderately convex, dorsum covered with white pubescence (Fig.
Head with fine frontal punctures, as large as eye facets, 0.5–1.0 diameter apart. Eyes finely faceted, interocular distance 0.56 times head width. Pronotal punctures slightly larger than those on frons, 1.0–2.0 diameters apart. Surface of elytra with punctures larger than those on pronotum, separated by 2.0–3.0 diameters. Prosternal carinae Y-shaped with stem approximately ⅓ as long as arm, arms broadly separated. Abdominal postcoxal lines strongly recurved and complete laterally (Fig.
Male unknown.
Holotype: female, Juisui, Taiwan, [23°31.23'N, 121°24.67'E, ca 300 m], 4. IV. 1974, Takeda S. leg (ELEU, Fig.
China (Taiwan).
This species is similar to Horniolus amamensis Miyatake and Horniolus kyushuensis Miyatake in general appearance, but can be separated from the latter by having incomplete abdominal postcoxal lines (Fig.
TL: 2.50–3.20 mm, TW: 1.80–2.41 mm, TH: 1.22–1.53 mm, TL/TW: 1.32–1.39, PL/PW: 0.51–0.53, EL/EW: 1.01–1.02, HW/PW: 0.60–0.62, PW/EW: 0.76–0.78.
Body rounded, moderately convex, dorsum covered with white pubescence (Fig.
Head with coarse frontal punctures, distinctly larger than eye facets, 0.5 diameter apart. Eyes finely faceted, interocular distance 0.53 times head width. Pronotal punctures smaller than those on frons, 1.0–2.0 diameters apart. Surface of elytra with punctures larger than those on pronotum, separated by 1.0–2.0 diameters. Prosternal carinae Y-shaped with stem ⅓ as long as arm, arms broadly separated. Abdominal postcoxal lines strongly recurved and distinctly incomplete laterally (Fig.
Male genitalia. Penis stout, evenly curved (Fig.
Female externally similar to male but with abdominal ventrite 5 truncate apically.
Holotype: male, No. 20070320057, CHINA: Hainan: Tongza, 18°54.22'N, 109°40.49'E, ca 470 m, VIII. 1995, Peng ZQ leg (SCAU). Paratypes (10): Hainan: 1♀ with same data as holotype. 1♂, Wuzhishan National Nature Reserve, 18°47.07'N, 109°31.98'E, ca 650 m, 22. XI. 1991, Peng ZQ leg. 2♀, Wuzhishan National Nature Reserve, 18°47.07'N, 109°31.98'E, ca 650 m, 8. VI. 1994, Tian MY leg. 1♂, Wuzhishan, 18°47.0'N, 109°31.98'E, ca 650 m, VIII.1995, Peng ZQ leg. 1♂1♀, Lianyuan, Nada, Danzhou City, 19°30.77'N, 109°29.77'E, VIII. 1995, Peng ZQ leg. 1♂, Maoyang Town, Qiongzhong County, 18°56.18'N, 109°30.31'E, ca 230 m, IX.1995, Peng ZQ leg. 1♂, Bawangling National Nature Reserve, 19°05.49'N, 109°06.38'E, ca 260 m, 3. IX. 1998, Peng ZQ leg. 1♂, Limushan National Forest Park, 19°14.05'N, 109°48.03'E, ca 160 m, 22.VII.2006, Dong XL leg (SCAU).
China (Hainan).
Etymology. The specific epithet refers to its type locality, Hainan Island.
Scymnus
fortunatus
Lewis, 1896: 38;
Scymnus (Scymnus) fortunatus
:
Scymnus (Pullus) fortunatus
:
Horniolus
fortunatus
:
This species closely resembles Horniolus dispar Weise in elytral pattern and male genitalia, but can be distinguished from it by having dark brown pronotum with black marking (Fig.
TL: 2.83 mm, TW: 1.91 mm, TH: 1.24 mm, TL/TW: 1.48, PL/PW: 0.53, EL/EW: 1.08, HW/PW: 0.63, PW/EW: 0.75.
Body elongate oval, slightly convex, dorsum covered with white pubescence (Fig.
Head with fine frontal punctures, slightly larger than eye facets, 1.0–2.0 diameters apart. Eyes finely faceted, interocular distance 0.54 times head width. Pronotal punctures as large as those on frons, 1.0–2.0 diameters apart. Surface of elytra with punctures larger than those on pronotum, separated by 2.0–3.0 diameters. Prosternal carinae Y-shaped with stem 1/7 as long as arm, arms narrowly separated. Abdominal postcoxal lines strongly recurved and complete laterally (Fig.
Male genitalia not studied in the present paper. According to the descriptions and illustrations given by
Female externally similar to male except for sexual characters. Abdominal ventrite 5 with apex rounded. Coxites triangular, elongated, outer and inner margins almost straight, tapering to blunt apices, each with dense, long terminal setae (Fig.
CHINA: Shaanxi: 1♀, Ningqiang County, 32°49.98'N, 106°14.46'E, ca 850 m, 7. VI. 1982, Collecter unknown (SCAU).
China (Shaanxi); Japan.
This species has variable pronotal colouration (
Horniolus
hisamatsui
Miyatake, 1976: 29;
This species is similar to Horniolus vietnamicus Miyatake in general appearance and male genitalia, but can be distinguished from it by the first pair of elytral spots with hind margin deeply emarginated at middle (Fig.
TL: 2.19–2.72 mm, TW: 1.51–1.94 mm, TH: 1.02–1.22 mm, TL/TW: 1.40–1.45, PL/PW: 0.52–0.54, EL/EW: 1.04–1.09, HW/PW: 0.64–0.66, PW/EW: 0.74–0.76.
Body elongate oval, slightly convex, dorsum covered with white pubescence (Fig.
Head with fine frontal punctures, as large as eye facets, 1.0–2.0 diameter apart. Eyes finely faceted, interocular distance 0.48 times head width. Pronotal punctures larger than those on frons, 1.0–2.0 diameters apart. Surface of elytra with punctures slightly larger than those on pronotum, separated by 2.0–3.0 diameters. Prosternal carinae Y-shaped with stem approximately ⅓ as long as arm, arms broadly separated. Abdominal postcoxal lines strongly recurved and complete laterally (Fig.
Male genitalia. Penis stout, evenly curved (Fig.
Female externally similar to male but with abdominal ventrite 5 rounded apically.
Holotype: female, Victoria Peak, Hong Kong, [22°16.55'N, 114°8.73'E], 29. IV. 1969, S. Hisamatsu leg (ELEU, Fig.
CHINA: Guangdong: 1♂, Shimentai National Nature Reserve, Yangqiu Mountains, 24°16.17'N, 113°17.54'E, ca 500 m, 6.X.2004, Wang XM leg. 2♂, South Subtropical Crops Research Institute, Zhanjiang City, 21°09.78'N, 110°16.45'E, ca 10 m, II. 2012, He YB leg. Hainan: 1♂, Yajia, Bawangling National Nature Reserve, 19°04.41'N, 109°09.08'E, ca 970 m, VIII.1995, Peng ZQ leg. 1♂, Tongza, 18°54.22'N, 109°40.49'E, ca 470 m, VIII. 1995, Peng ZQ leg. 2♂, Bawangling National Nature Reserve, 19°05.49'N, 109°06.38'E, ca 260m,5. V. 2005, Wang XM leg. 1♂1♀, Baoting County, 18°37.47'N, 109°41.53'E, ca 70 m, 21.VII.1996, Peng ZQ leg. 1♀, Limushan National Forest Park, 19°14.05'N, 109°48.03'E, ca 160 m, 22.VII.2006, Dong XL leg. 1♀, Wuzhishan National Nature Reserve, 18°47.07'N, 109°31.98'E, ca 650m, 22. XI. 1991, Peng ZQ leg. 1♀, Wuzhishan National Nature Reserve, 18°47.07'N, 109°31.97'E, ca 700m, 3. V. 1996, Peng ZQ leg. 1♀, Yinggen Town, Qiongzhong County, 19°02.10'N, 109°49.84'E, ca 200 m, 15. VII. 1999, Peng ZQ leg. Guangxi: 1♂, Pinglongshan, Fulong, Shangsi, 21°49.88'N, 107°56.79'E, ca 160m, 29. VII. 2005, Wang XM leg. Tibet: 1♀, Motuo County, Linzhi City, 29°19.30'N, 95°18.33'E, ca 760 m, 17. X. 2009, Chen XS leg. 2♂, Beibeng Village, Motuo County, 29°14.31'N, 95°10.58'E, ca 800 m, 9. X. 2011, Huo LZ et al. leg (SCAU).
China (Guangdong, Hong Kong, Hainan, Guangxi, Tibet); Nepal.
Horniolus
sonduongensis
Hoàng, 1979: 12;
This species is similar to Horniolus vietnamicus Miyatake and Horniolus bimaculatus Miyatake in general appearance and can be separated from these species only by the male genitalia.
TL: 2.76–3.34 mm, TW: 2.03–2.45 mm, TH: 1.40–1.63 mm, TL/TW: 1.35–1.36, PL/PW: 0.54–0.58, EL/EW: 1.02–1.04, HW/PW: 0.60–0.63, PW/EW: 0.72–0.75.
Body rounded oval, moderately convex, dorsum covered with white pubescence (Fig.
Head with coarse frontal punctures, slightly larger than eye facets, 0.2–0.5 diameter apart. Eyes densely faceted, interocular distance 0.54 times head width. Pronotal punctures smaller than those on frons, 2.0–3.0 diameters apart. Surface of elytra with punctures much larger than those on pronotum, separated by 1.0–2.0 diameters. Prosternal carinae Y-shaped with stem approximately ⅓ as long as arm, the arms broadly separated. Abdominal postcoxal lines strongly recurved and complete laterally (Fig.
Male genitalia. Penis slender and long (Fig.
Female externally similar to male but with abdominal ventrite 5 truncate apically.
CHINA: Fujian: 1♂, Xiangxi Village, Huboliao National Nature Reserve, Nanjing County, 24°31.07'N, 117°17.08'E, ca 240 m, 18. VIII. 2012, Li WJ leg. Guangdong: 1♂5♀, Nankunshan National Nature Reserve, Longmen County, Huizhou City, 23°38.90'N, 113°51.58'E, 460 m, 15. VI. 2014, Ren SX leg. Guangxi: 1♂, Pinglongshan, Fulong, Shangsi, 21°49.88'N, 107°56.79'E, ca 160m, 29. VII. 2005, Wang XM leg. 2♂1♀, Naqin Town, Fangchenggang City, 21°49.52'N, 108°02.11'E, ca 100 m, 30.VII.2005, Zhang CW and Wang XM leg. 2♀, Nonggang National Nature Reserve, Longzhou County, 22°28.22'N, 106°57.31'E, ca 230 m, 3. VIII. 2005, Qin ZQ and Zhang CW leg. 2♀, Daqing Mountains, Pingxiang, 24°54.76'N, 113°2.83'E, 2. VIII. 2005, Zhang CW and Wang XM leg. 2♀, Longguang, 29-30. VII. 1985, Pang XF leg. Yunnan: 1♂, Xiaowei Mountains, Hekou, 22°53.86'N, 103°34.04'E, ca 900m, 23. IV. 2008, Hao JY leg. 1♂, Mengdui, Zhenkang, 23°53.47'N, 98°53.33'E, 1400m, 18. V. 2008, Liang JB leg. 2♀, Jinuo Mountains, Jinghong, Xishuangbanna, 22°02.21'N, 101°00.35'E, ca 900 m, 6. V. 2009, Chen XS leg. 1♀, Jinuo Mountains, Xishuangbanna, 22°02.21'N, 101°00.35'E, ca 900 m, 28. IV. 2008, Liang JB leg. 1♂2♀, Gongxin, Menglian, 22°18.27'N, 99°19.31'E, 1500 m, 8. V. 2008, Hao JY leg. 1♂, No. 213 Highway, Mengla, 21°33.77'N, 101°34.85'E, ca 700 m, 12-13. X. 2006, Wang XM leg. 1♂, Nature Reserve, Menglun, Mengla, 21°55.27'N, 101°16.64'E, ca 550m, 12-13, X. 2006, Wang XM leg. 1♂, Mengla, Xishuangbanna, 21°26.59'N, 101°38.01'E, ca 1160m, 23. VIII. 2005, Wang XM leg. VIETNAM: 1♂, Vietnam, Prov. Gialai-Contum, Buonloi, 14°06.73'N, 107°58.30'E, ca 700 m, 28. V. 1985, Zaitzev U leg (SCAU).
China (Fujian, Guangdong, Guangxi, Yunnan) new distribution; Vietnam.
This species has variable colour pattern on elytra. In the original description of this species,
Horniolus amamensis Miyatake, 1963
Horniolus amamensis Miyatake, 1963: 10;
Distribution. Japan.
Horniolus bimaculatus Miyatake, 1976
Horniolus bimaculatus Miyatake, 1976: 35.
Distribution. Malaysia.
Horniolus dispar Weise, 1901
Horniolus dispar Weise, 1901: 443;
Scymnus (Pullus) sp.:
Distribution. Sri Lanka.
Horniolus fortunatus (Lewis, 1896)
Scymnus fortunatus Lewis, 1896: 38;
Scymnus (Scymnus) fortunatus:
Scymnus (Pullus) fortunatus:
Horniolus fortunatus:
Distribution. China (Shaanxi); Japan.
Horniolus guimeti (Mulsant, 1850)
Scymnus guimeti Mulsant, 1850: 979;
Horniolus guimeti:
Distribution. Malaysia, Bangladesh.
Notes.
Horniolus hainanensis Chen & Ren, sp. n.
Distribution. China (Hainan).
Horniolus hisamatsui Miyatake, 1976
Horniolus hisamatsui Miyatake, 1976: 29;
Distribution. China (Guangdong, Hong Kong, Hainan, Guangxi, Tibet); Nepal.
Horniolus kyushuensis Miyatake, 1963
Horniolus kyushuensis Miyatake, 1963: 9;
Distribution. Japan.
Horniolus nigripes Miyatake, 1976
Horniolus nigripes Miyatake, 1976: 33;
Distribution. India.
Horniolus novempunctatus Miyatake, 1979
Horniolus novempunctatus Miyatake, 1979: 105;
Distribution. China (Taiwan).
Horniolus okinawensis Chûjô & Miyatake, 1963
Horniolus okinawensis Chûjô & Miyatake in Miyatake, 1963: 11;
Distribution. Japan.
Horniolus siamensis Miyatake, 1976
Horniolus siamensis Miyatake, 1976: 31;
Distribution. Thailand.
Horniolus sonduongensis Hoàng, 1979
Horniolus sonduongensis Hoàng, 1979: 12; 1982: 122;
Distribution. China (Fujian, Guangdong, Guangxi, Yunnan); Vietnam.
Horniolus sororius Poorani, 2015
Horniolus sororius Poorani, 2015: 7.
Distribution. India.
Horniolus vietnamicus Miyatake, 1976
Horniolus vietnamicus Miyatake, 1976: 36;
Distribution. Vietnam.
We would like to express great appreciation to Dr. Takanobu Kitano (Ehime University, Japan) for a loan of type specimens. We are also grateful to Dr. Shaukat Ali (SCAU), who helped to check the English text. Our sincere thanks are extended to the anonymous reviewers for their valuable and constructive comments and suggestions on our manuscript. The present study was supported by the National Natural Science Foundation of China (31601878, 31501884) and the Guangdong Natural Science Foundation (2014A030310493), the Science and Technology Program of Guangzhou (151800033) and the International Cooperation Project of Guangzhou Science and Technology Innovation Committee.