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Three new species of the genus Zethus Fabricius, 1804 (Hymenoptera, Vespidae, Eumeninae) from China, with an updated key to the Oriental species
expand article infoHua-Chuan Wang, Bin Chen, Ting-Jing Li
‡ Chongqing Normal University, Chongqing, China
Open Access

Abstract

Three new species, namely Zethus striatus sp. nov., Z. asperipunctatus sp. nov. and Z. nullimarginatus sp. nov. from China are described and illustrated. Z. tumidus Nguyen & Carpenter, 2016 and Z. angulatus Nguyen & Carpenter, 2016 are newly recorded from China. An updated key to the Oriental species of the genus is provided.

Keywords

Zethus, Eumeninae, China, new species, new records

Introduction

Zethus Fabricius, 1804 is the most species-rich genus within the subfamily Eumeninae with 275 valid species, containing four subgenera: Madecazethus Giordani Soika, Zethoides Fox, Zethus Fabricius and Zethusculus Saussure, among which Madecazethus is endemic to Madagascar with two species, both Zethoides and Zethusculus are restricted to the Neotropical and Nearctic regions, and the subgenus Zethus Fabricius is widely distributed worldwide excluding the Australian region (Bohart and Stange 1965; Giordani Soika 1979; Gusenleitner 2011; Pannure et al. 2016, 2018; Yeh and Lu 2017; Hermes and Lopes 2018; Tan et al. 2018). So far, there are 26 described species in the Oriental region. The first review on the Oriental Zethus concluding a key to six recognized species was given and then an updated key to eight species was provided (Giordani Soika 1941, 1958). In the following 60 years, eighteen more species were found and described, respectively (Giordani Soika 1995; Gusenleitner 1988, 2001, 2007, 2010; Gusenleitner and Gusenleitner 2013; Nguyen and Carpenter 2016, Nguyen and Xu 2017; Selis 2017, 2018; Yeh and Lu 2017; Tan et al. 2018). In our study of the genus Zethus, we systematically sorted out all of the references to the Oriental species. Based on the references and the specimens which were long-term collection throughout China by us and other Chinese museums, a key to the Oriental species are updated and three species are new to science. In addition, both Z. tumidus Nguyen & Carpenter and Z. angulatus Nguyen & Carpenter are recorded firstly from China.

Materials and methods

The pinned specimens examined were collected by using an insect net. Those specimens are deposited in Chongqing Normal University, Chongqing, China (CQNU), Central South University of Forestry and Technology, Changsha, China (CSUFT), Museum of Hebei University, Baoding, China (MHBU), Shanghai Entomological Museum C.A.S, Shanghai, China (SEM). Descriptions and measurements were made under a stereomicroscope (Olympus SZ61). All figures were taken with Keyence VHX-5000 digital microscope and Photoshop CS 6 was used to make the plates. Body length was measured from the anterior margin of the head to the posterior margin of metasomal tergum 2. For the density description of punctures, “sparse” means that distance is larger than punctures diameter and “dense” means less than the diameter. Terminology principally follows Bohart and Stange (1965) and Yamane (1990). The abbreviations used in this paper are shown as follows:

AE broadened apical expansion of metasomal sternum 1

BS slender basal stem of metasomal sternum 1

A1 for antennal segment 1,

A2 for antennal segment 2,

T1 for metasomal tergum 1,

T2 for metasomal tergum 2,

S1 for metasomal sternum 1,

S2 for metasomal sternum 2, and so on.

Taxonomy

Zethus Fabricius, 1804

Zethus Fabricius, 1804: xii, 282. Type species: “Zethus coeruleo-pennis Fab.” [= Vespa coeruleopennis Fabricius, 1798], by subsequent designation of Latreille, 1810: 328, 438.

Zethus striatus Wang & Li, sp. nov.

Figs 1–12

Material examined

Holotype, ♀: CHINA, Guangxi, Baise City, Tianlin County, CengWangLaoShan National Nature Reserve, Dalongping, 24°29.361'N, 106°24.076'E, 24–25.VIII.2007, Xiang Li leg. (CQNU).

Description

Female: body length 15.3 mm (Fig. 1), fore wing length 13.7 mm. Black, the following parts yellow: clypeus except base and central middle, spot on dorso-inner margin of antennal socket, antennal scape ventrally, paired transverse middle spots on dorsal side of pronotum, apical bands on T1 and T2; tegula dark brown (Fig. 5).

Figures 1–12. 

Zethus striatus sp. nov., holotype 1 habitus in dorsal view, ♀ 2 vertex, ♀ 3 head in frontal view, ♀ 4 vertex in dorsal-lateral view, ♀ 5 mesosoma, ♀ 6 propodeum in dorsal view, ♀ 7 propodeum in lateral view, ♀ 8 metasoma in lateral view, ♀ 9 metasoma in dorsal view, ♀ 10 T1, ♀ 11 S1, ♀ 12 T2, ♀.

Head. Head with short setae, their length slightly longer than posterior ocellar diameter; head about 2.1× wider than long in dorsal view (Fig. 2), wider than high in frontal view, about 1.2× as wide as high (Fig. 3); mandible with four blunt teeth and short setae; clypeus convex in lateral view and about 1.3× as wide as high in frontal view, with basal margin nearly straight, apical margin of clypeus frontally truncated and laterally cambered, clypeus punctate-reticulate with sparse setae (Fig. 3); frons with sparse setae and dense punctures; vertex and gena with dense punctures; gena in lateral view as wide as eye, without longitudinal carina; distance from posterior ocelli to apical margin of vertex 1.7× as long as distance from posterior ocelli to inner eye margin (Fig. 2); occipital carina developed laterally and weak dorsally (Fig. 4); antennal scape 3× as long as its maximum width, A3 1.4× as long as its maximum width, A4 as long as its maximum width, A5–11 wider than long, A12 bullet-shaped, as long as its basal width.

Mesosoma. Length of mesosoma about 1.3× as long as wide in dorsal view (Fig. 5); pronotal carina weak laterally and indistinct dorsally, pronotum with dense punctures and slightly reticulate dorsally; notaulix distinct on basal half of mesoscutum, mesoscutum with deep and dense punctures, area between punctures striate, in lateral view weakly convex; tegula smooth, with very sparse punctures, its posterior lobe triangular and well developed which exceeds parategula posteriorly; epicnemial carina distinct; mesopleura with deep and dense punctures, slightly sparse ventrally; scutellum flattened, with deep and dense punctures, area between punctures striate, longitudinal furrow on the middle of scutellum (Fig. 5); metanotum sloping down posteriorly, with deep punctures; metapleuron almost smooth; propodeum (Fig. 6) with strong striae and lateral carina, its dorsolateral surface with distinct and oblique striae and strong longitudinal carina along submedian carina, posterior surface of propodeum with transverse striae along median carina, submarginal carina produced into lamella above propodeal valvulae, its lateral surface with punctures along lateral carina and weak striae on its lower half (Fig. 7); orifice more or less angled dorsally (Fig. 6).

Metasoma. T1 about 2.5× as long as wide in dorsal view, gradually widening from one-third of the base, then nearly parallel-sided apically, with maximum width 3× its basal width, without medial carina, T1 with deep and dense macropunctures and sparse setae (Fig. 10), lateral carina of T1 present in ventral view (Fig. 11); BS of S1 with median longitudinal carina and narrow from its middle to apex, coarsely punctate on apical margin of BS and base half of AE (Fig. 11); T2 without petiole and with developed apical lamella, about 1.2× as long as wide in dorsal view, T2 with deep and dense punctures (Fig. 12); S2 swollen from the base to near midpoint, subsequent portion nearly straight in profile (Fig. 8), its apical margin with lamella; T3 with developed and raised apical lamella (Figs 8, 9, 12); subsequent terga and sterna with deep punctures, but slightly smaller than those on T2.

Male

Unknown.

Distribution

China: Guangxi.

Remarks

The species is similar to Z. trimaculatus Cameron, 1904 from Vietnam, Laos and India by the characters: body with dense punctures (Fig. 1), occipital carina developed laterally and weak dorsally (Fig. 4), pronotal carina weak laterally and indistinct dorsally (Fig. 5), S2 not tuberculate in profile (Fig. 8). It differs from Z. trimaculatus and all other members of the genus by the following character combination: apex of clypeus yellow, apical margin of clypeus frontally truncated (Fig. 3) and laterally cambered, BS of S1 with longitudinal carina (Fig. 11), propodeum with strong lateral carina and its dorsolateral and posterior surface with strong striae (Fig. 6).

Etymology

The specific name striatus is derived from Latin word: striatus, referring to propodeum with strong striae in dorsal view.

Zethus asperipunctatus Wang & Li, sp. nov.

Figs 13–25

Material examined

Holotype, ♀: CHINA, Yunnan, Lijiang City, Yulong County, Hutiaoxia, 27°22.953'N, 99°53.157'E, 7.VI.2009, Meicai Wei leg. (CSUFT).

Description

Female: body length 16.2 mm (Fig. 13), fore wing length 13.7 mm. Black, the following parts ferruginous: marking on dorso-inner margin of antennal socket, antennal scape lower area ventrally, pronotum in dorsal view, tegula, dot on lateral of metanotum, apical bands on T1, T2, T3 and middle of S2 (Fig. 13).

Figures 13–25. 

Zethus asperipunctatus sp. nov., holotype 13 habitus in dorsal view,♀ 14 head in frontal view, ♀ 15 vertex, ♀ 16 clypeus, ♀ 17 gena, ♀ 18 antenna, ♀ 19 mesosoma, ♀ 20 propodeum in dorsal view, ♀ 21 propodeum in lateral view, ♀ 22 metasoma in lateral view, ♀ 23 T1, ♀ 24 S1, ♀ 25 T2, ♀.

Head. Head with long setae, their length distinctly longer than 2× posterior ocellar diameter; head about 1.3× as wide as high in frontal view (Fig. 14), about 1.7× wider than long in dorsal view (Fig. 15); mandible with four blunt teeth and dense setae, its outer surface with coarse punctures; clypeus convex in lateral view and about 1.3× as wide as high in frontal view, with basal margin almost straight, minutely bi-dentate apically, depressed space between teeth with a median carina, width of truncation 1/3× width of clypeus between inner eye margins, clypeus with dense and long setae and dense punctures (Fig. 16); frons with long setae and dense punctures; vertex and gena with dense punctures; gena slightly wider than eye in lateral view and without longitudinal carina (Fig. 17); distance from posterior ocelli to apical margin of vertex 1.7× as long as distance from posterior ocelli to inner eye margin (Fig. 15); occipital carina complete (Fig. 15); antennal scape 2.7× as long as its apical width, A3 1.8× as long as its maximum width, A4 slightly longer than its maximum width, A5–11 wider than long, A12 bullet-shaped, as long as its basal width (Fig. 18).

Mesosoma. Length of mesosoma about 1.3× as long as wide in dorsal view (Fig. 19); pronotal carina complete, pronotum with distinct humeral angle and reticulate punctures dorsally; notaulix complete, mesoscutum with dense punctures, gradually shallow from the anterior to posterior portion; tegula smooth, with dense and short setae on its anterior and posterior lobe; epicnemial carina distinct; mesopleura with deep and dense punctures; scutellum flattened, and with shallow punctures and middle longitudinal furrow almost invisible, distance between punctures about as wide as punctures diameter; punctures on metanotum like those on scutellum, but deeper; metapleuron almost smooth; propodeum dull, with lateral carina and without submedian carina, its dorsolateral surface with reticulate striae (Fig. 20), submarginal carina produced into lamella above propodeal valvulae, lateral surface of propodeum with sparse and fine punctures (Fig. 21); orifice angled dorsally (Fig. 20).

Metasoma. T1 about 2.2× as long as wide, with medial carina from basal margin to one-third of the tergum, gradually widening from one-fourth of the base, then narrowly toward apex, with maximum width about 3.3× its basal width, T1 with coarse and dense punctures (Fig. 23) and lateral carina of T1 present wholly (Fig. 24); BS of S1 without longitudinal carina and with sparse punctures, lateral portion of AE with weak striae and sporadic punctures (Fig. 24); T2 without distinct petiole, gradually swollen from the base to midpoint and nearly straight to apex in lateral view, with developed apical lamella, about 1.3× as long as wide in dorsal view, T2 with dense punctures, which gradually sparse from the base to apex, distance between punctures on the base distinctly less than its diameter and 1–2× larger than puncture diameter on apical margin (Fig. 25); S2 swollen from the base to near midpoint, subsequent portion nearly straight in profile (Fig. 22), punctures on the base of S2 large, punctures on subsequent portion like those on T2, but punctures on lateral portion dense, apical margin of S2 with lamella, T3 and S3 with dense and small punctures, T3 with thick apical lamella, and subsequent terga and sterna with small punctures, distance between punctures about as wide as its diameter.

Male

Unknown.

Distribution

China: Yunnan.

Remarks

This new species resembles Z. nigerrimus Gusenleitner, 2001 from China, Malaysia, Laos and Vietnam, with which it has the following common characters: clypeus minutely bi-dentate apically, depressed space between teeth with a median ridge (Fig. 16), T1 about 2.2× as long as wide (Fig. 23), T2 without distinct petiole (Fig. 25), S2 not tuberculate in profile (Fig. 22). It differs from Z. nigerrimus and all other members of the genus by the following character combination: body with ferruginous marking (Fig. 13), gena without carina (Fig. 17); BS of S1 with sparse punctures (Fig. 24), S2 blunt angulate in profile (Fig. 22), and propodeum and metasoma dull and with dense setae and punctures (Figs 13, 21, 22).

Etymology

The specific name asperipunctatus is derived from two Latin words: asper and punctatus, referring to metasoma dull and with dense punctures.

Zethus nullimarginatus Wang & Li, sp. nov.

Figs 26–35

Material examined

Holotype, ♀: CHINA, Fujian, Longyan City, Changting County, Sidu Town, 25°39.126'N, 116°12.253'E, 1.V.1951, Gentao Jin & Yangming Lin leg. (SEM).

Description

Female: body length 15.2 mm (Fig. 26), fore wing length 13.5 mm. Almost black, the following parts yellow: spot on dorso-inner margin of antennal socket (Fig. 27), apical interrupted band on T1, apical complete band on T2; tegula dark brown (Fig. 29).

Figures 26–35. 

Zethus nullimarginatus sp. nov., holotype 26 habitus in dorsal view, ♀ 27 head in frontal view, ♀ 28 vertex, ♀ 29 mesosoma, ♀ 30 propodeum in dorsal view, ♀ 31 propodeum in lateral view, ♀ 32 propodeum in dorsal-lateral view, ♀ 33 metasoma in lateral view, ♀ 34 T1, ♀ 35 S1, ♀.

Head. Head wider than high, about 1.3× as wide as high in frontal view (Fig. 27), about 1.8× wider than long in dorsal view (Fig. 28); mandible with four teeth and dense setae, its outer surface with irregular punctures; clypeus convex in lateral view and about 1.6× as wide as high, with basal margin straight, apical margin near truncated, width of truncation 1/3× width of clypeus between inner eye margins, clypeus punctate-reticulate with dense long setae (Fig. 27); punctures on frons reticulate; vertex and gena with dense punctures; gena without longitudinal carina in lateral view; distance from posterior ocelli to apical margin of vertex 1.8× as long as distance from posterior ocelli to inner eye margin (Fig. 28); occipital carina complete (Fig. 28); antennal scape 2.8× as long as its maximum width, A3 1.7× as long as its maximum width, A4 slightly longer than its maximum width, A5–11 wider than long, A12 bullet-shaped, slightly longer than its basal width.

Mesosoma. Length of mesosoma about 1.4× as long as wide in dorsal view (Fig. 29); pronotal carina complete and developed, pronotum with coarse punctures dorsally, weak striae in lower lateral surface; notaulix complete, mesoscutum with dense punctures, gradually shallow from the anterior to posterior portion (Fig. 29); tegula smooth, with dense and short setae on its anterior and posterior lobe, its posterior lobe truncated (Fig. 29); mesopleura with dense punctures, slightly sparse ventrally; scutellum flattened, and with shallow punctures and weak middle longitudinal furrow; punctures on metanotum dense and coarse; metapleuron smooth; propodeum dull, with coarse surface in dorsal view and lateral carina very weak, without submedian carina (Fig. 30), its lateral surface with sporadic punctures and without striae (Fig. 31), submarginal lamella almost absent above propodeal valvulae (Fig. 32).

Metasoma. T1 about 2.5× as long as wide, with medial carina from basal margin to one-fourth of tergum, gradually widening from one-fifth of the base, then distinctly narrow toward apex, with maximum width 3× its basal width, T1 with punctures, distance between punctures about equal to the diameter (Fig. 34), lateral carina of T1 disappeared ventrally (Fig. 35); BS of S1 with sparse punctures, AE of S1 with weak and irregular striae and sporadic punctures (Fig. 35); T2 gradually swollen from the base to apical margin in lateral view, with developed apical lamella, about 1.2× as long as wide in dorsal view, T2 with sparse punctures, area between punctures with fine punctures, distance between punctures 1–2× larger than puncture diameter (Fig. 33); S2 gradually swollen from basal to apical margin in profile (Fig. 33); punctures on S2 slightly larger than those on T2, punctures on center area of S2 sparse, S2 with apical lamella; T3 with dense punctures and thick apical lamella; apical margin of S3 with dense punctures like those on T3; subsequent terga and sterna with slightly sparse micropunctures.

Male. Unknown.

Distribution

China: Fujian.

Remarks

The species resembles Z. velamellatus Tan, 2018 from Zhejiang, China by propodeum without submarginal lamella (Fig. 32), S2 gradually swollen from basal to apical margin in profile (Fig. 33). It differs from Z. velamellatus and all other members of the genus by the following character combination: apical margin of clypeus truncated (Fig. 27), the posterior lobe of tegula truncated (Fig. 29), propodeum without submarginal lamella (Fig. 32), T1 about 2.5× as long as wide, narrowly toward apex (Fig. 34), lateral carina of T1 disappeared ventrally (Fig. 35).

Etymology

The specific name nullimarginatus is derived from two Latin words: null and marginatus, referring to lateral carina of T1 disappeared ventrally.

Zethus angulatus Nguyen & Carpenter, 2016, new record

Figs 36–44

Zethus angulatus Nguyen & Carpenter, 2016: 27.

Material examined

1♀: CHINA, Guangxi, Guiling City, Xingan County, Gaozhai Village, 25°50.901'N, 110°28.976'E, 19.VII.2015, Tingjing Li leg. (CQNU); 1♀: CHINA, Guangxi, Hechi City, Huanjiang County, Chuanshan Town, Linglang Village, 25°1.385'N, 108°5.761'E, 22.VII.2018, Qian Han et al. leg. (CQNU); 1♂: CHINA, Guangdong, Shaoguan City, Shixing County, CheBaLing National Nature Reserve, 24°43.503'N, 114°15.658'E, 22.VII.2018, Chengqiang Wang leg. (CQNU).

Diagnosis

Female (Fig. 36): black, with the following parts yellow: spot on near dorso-inner margin of antennal socket and lateral carina of T1. Clypeus emarginated at basal and apical margin, clypeus punctate-reticulate and with long setae (Fig. 37); A12 bullet-shaped (Fig. 39); notaulix complete, punctures on mesoscutum gradually shallow from the anterior to posterior portion (Fig. 40); scutellum with punctures and middle longitudinal furrow; metapleuron with transverse striae; propodeum with lateral carina (Fig. 41) and transverse striae along median carina (Fig. 42), its lateral surface with large punctures in upper half (Fig. 41). T1 about 3× as long as wide in dorsal view, slightly narrow toward apical margin, T1 with coarse and deep punctures (Fig. 43); BS of S1 with longitudinal carina (Fig. 44), T2 with apical lamella, punctures on the near base of T2 denser and larger than other portion of tergum (Fig. 43); S2 with short apical lamella and obtuse angle in lateral view (Fig. 43); punctures on T3 and S3 dense and deep, T3 with thick apical lamella.

Figures 36–45. 

Zethus angulatus Nguyen & Carpenter, 2016 36 habitus in lateral view, ♀ 37 head in frontal view, ♀ 38 antenna, ♂ 39 antenna, ♀ 40 mesosoma, ♀ 41 propodeum in lateral view, ♀ 42 propodeum in dorsal view, ♀ 43 metasoma in lateral view, ♀ 44 S1, ♀ 45. Zethus dolosus Bingham, 1897, mesosomal segment 2 in lateral view, ♀.

Male: structure as in female, but differing as follows: longitudinal pale yellow stripe on mandible, apical margin of clypeus deeply emarginated with the emargination forming a semicircle, A13 elongate, slightly curved (Fig. 38), propodeum with strong and oblique striae along median carina.

Distribution

China: Guangdong and Guangxi (new record); Vietnam.

Zethus tumidus Nguyen & Carpenter, 2016, new record

Figs 46–53

Zethus tumidus Nguyen & Carpenter, 2016: 29.

Material examined

1♂: CHINA, Hainan, Changjiang County, Bawangling, 19°07.270'N, 109°05.009'E, 11–12.VII.2007, Yibin Ba & Juntong Lang leg. (MHBU).

Diagnosis

Male (Fig. 46): black, with yellow spot on dorso-inner margin of antennal socket and brown on S1 and the base of S2. Clypeus with reticulate punctures, apical margin distinctly emarginated (Fig. 47); ocelli large, its diameter as wide as antennal socket (Figs 47, 48); occipital carina complete (Fig. 48); A13 elongated (Fig. 49). Notaulix developed, mesoscutum with distinct punctures (Fig. 50); propodeum with lateral carina (Fig. 51), submarginal carina produced into developed lamella, its lateral surface without distinct punctures and striae and with deep and large punctures along lateral carina (Fig. 52). T1 2.4× as long as wide in dorsal view, maximum width 3× its basal width, then narrowly toward apical margin, with a medial carina which runs from basal margin to one-third of tergum, punctures on T1 large and dense (Fig. 53); BS of S1 with irregular and longitudinal striae; T2 with slightly dense punctures; T2 and S2 in lateral view gradually convex from basal to apical margin, with developed apical lamella; T3 and S3 with dense punctures; T3 with thick apical lamella.

Figures 46–53. 

Zethus tumidus Nguyen & Carpenter, 2016 46 habitus in dorsal view, ♂ 47 head in frontal view 48 vertex 49 antenna 50 mesosoma 51 propodeum in dorsal view 52 propodeum in lateral view 53 T1.

Distribution

China: Hainan (new record); Vietnam.

Key to species of the genus Zethus from the Oriental region

1 T1 about 5× as long as wide in dorsal view Z. fulgens Gusenleitner, 2007
T1 at most 4.2× as long as wide in dorsal view (Figs 10, 23, 34, 43, 53) 2
2 Head and mesosoma with dense and long golden orange setae 3
Head and mesosoma without dense golden orange setae 5
3 Apical lamella of T3 indistinct; mesoscutum with large and dense punctures Z. celebensis Giordani Soika, 1958
Apical lamella of T3 distinct; mesoscutum with indistinct punctures 4
4 S2 with developed lamella; in female, apical margin of S3 with a punctate median lobe; in male, antennae black, apical flagellomere rounded apically; apical margin of clypeus without teeth Z. soikai Selis, 2017
S2 without apical lamella; in female, apical margin of S3 without lobe; in male, antennae orange, apical flagellomere pointed apically; apical margin of clypeus with two triangular teeth Z. luzonensis Giordani Soika, 1941
5 S2 not tuberculate in lateral view (Figs 8, 22, 33, 43) 6
S2 tuberculate in lateral view (Fig. 45) 22
6 Both T2 and T3 without lamellae Z. puehringeri Gusenleitner & Gusenleitner, 2013
Both T2 and T3 with lamellae (Figs 12, 25, 33, 43, 45, 46) 7
7 Submarginal lamella of propodeum absent (Fig. 32) 8
Submarginal lamella of propodeum present (Figs 7, 21, 41, 52) 9
8 Apical margin of clypeus without depressed space and lateral tooth (Fig. 27); lateral carina of T1 disappeared in ventral view (Fig. 35) Z. nullimarginatus sp. nov.
Apical margin of clypeus with depressed space between lateral tooth; lateral carina of T1 present in ventral view Z. velamellatus Tan, 2018
9 Occipital carina developed laterally, weak dorsally (Fig. 4); pronotal carina almost indiscernible dorsally (Fig. 5) 10
Occipital carina and pronotal carina complete and visible (Figs 19, 29, 40, 50) 11
10 Apical margin of clypeus emarginated; propodeum with weak lateral carina Z. trimaculatus Cameron, 1904
Apical margin of clypeus frontally truncated and laterally cambered (Fig. 3); propodeum with strong lateral carina (Fig. 6) Z. striatus sp. nov.
11 Apical margin of clypeus almost truncated or rounded (Figs 16, 27) 12
Apical margin of clypeus distinctly emarginated (Figs 47, 37) 19
12 T1 at least 3.5× as long as wide in dorsal view 13
T1 at most 2.6× as long as wide in dorsal view (Figs 23, 34, 53) 16
13 Metapleuron with strong and short striae 14
Metapleuron without striae 15
14 Scutellum with weak longitudinal furrow in middle Z. malayanus Gusenleitner, 2010
Scutellum with deep longitudinal furrow on the apex behind Z. quadridentatus Cameron, 1902
15 Tegula and leg ferruginous; T1 narrowly toward apical margin Z. varipunctatus Cameron, 1902
Tegula and leg black; T1 nearly parallel-sided apically Z. planiclypeus Gusenleitner, 1988
16 T2 without distinct petiole (Fig. 25) 17
T2 with petiole 18
17 Mesosoma and metasoma almost black; gena with a longitudinal carina Z. nigerrimus Gusenleitner, 2001
Mesosoma and metasoma with ferruginous marking (Fig. 13); gena without longitudinal carina (Fig. 17) Z. asperipunctatus sp. nov.
18 T1 gradually widening from one-sixth from the base, with medial carina from basal margin to near apical margin; submarginal carina of propodeum produced into pointed lamella Z. nanlingensis Nguyen & Xu, 2017
T1 gradually widening from one-fourth from the base, with medial carina from basal margin to one-fourth of tergum; submarginal carina of propodeum produced into round and short lamella Z. propodeus Nguyen & Carpenter, 2016
19 T1 about 3× as long as wide in dorsal view Z. angulatus Nguyen & Carpenter, 2016
T1 less than 2.5× as long as wide in dorsal view 20
20 A3 2× as long as wide; ocellar diameter as wide as antennal socket (Fig. 47) Z. tumidus Nguyen & Carpenter, 2016
A3 less than 2× its width; ocellar diameter narrower than antennal socket 21
21 Gena without longitudinal carina; in male, mandible separated from middle tooth by a broad notch; clypeus black Z. taiwanus Yeh & Lu, 2017
Gena with a longitudinal carina; in male, mandible not separated by a broad notch; clypeus with yellow marking Z. tansoneus Nguyen & Carpenter, 2016
22 T1 swollen at the base, with lateral margins narrowly toward apex 23
T1, subcylindrical, nearly parallel-sided apically 25
23 Propodeum without lateral carina Z. bakeri Giordani Soika, 1995
Propodeum with lateral carina 24
24 A13 slightly curved; punctures on T2 large and slightly sparse; clypeus with yellow marking Z. mandibularis Giordani Soika, 1995
A13 straight; punctures on T2 fine and dense; clypeus black Z. malabarica Giordani Soika, 1995
25 Apical lamella of the S2 not reaching the lateral margins of the same sternum Z. ceylonicus de Saussure, 1867
Apical lamella of the S2 reaching the lateral margins of the same sternum 26
26 Body glossy and almost without punctures Z. improcerus Giordani Soika, 1995
Body with coarse and wide punctures 27
27 Lateral surface of propodeum with oblique striae in the lower half Z. dolosus Bingham, 1897
Lateral surface of propodeum smooth in lower half 28
28 Metasomal segments 3–6 with long and dense setae Z. albopilosus Giordani Soika, 1995
Metasomal segments 3–6 with short and sparse setae Z. indicus Giordani Soika, 1958

Acknowledgements

We are very grateful to Prof. James M. Carpenter (American Museum of Natural History, New York, USA) and Dr. P. Girish Kumar (Western Ghat Regional Centre, Zoological Survey of India, Kozhikode, India) for providing copies of many references. We sincerely thank Prof. Meicai Wei (Central South University of Forestry and Technology, Changsha, China), Prof. Guodong Ren (Museum of Hebei University, Baoding, China) and Prof. Haisheng Yin (Shanghai Entomological Museum C.A.S., Shanghai, China). This study was funded by the National Natural Science Foundation of China (Nos: 31772490, 31372247, 31000976), Young Talent Incubation Programme of Chongqing Normal University (14CSDG07).

References

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