Syntomernus Enderlein, 1920

Samartsev, Konstantin & Ku, Deok-Seo, 2020, New species of the genera Bracon Fabricius and Syntomernus Enderlein (Hymenoptera, Braconidae, Braconinae) from South Korea, ZooKeys 999, pp. 1-47 : 1

Genus Syntomernus Enderlein, 1920

Syntomernus Enderlein 1920: 121 (type species: Syntomernus pusillus Enderlein, 1920). Shenefelt 1978: 1728; Quicke 1987: 89 (in key); 132; van Achterberg et al. 2009: 664.

Ficobracon van Achterberg & Weiblen, 2000: 52 (type species: Ficobracon brusi van Achterberg & Weiblen, 2000). Wei et al. 2013: 466; syn. nov. Syntomernus brusi (van Achterberg & Weiblen, 2000), comb. nov.

Remarks.

The members of the Bracon asphondyliae species group ( Maetô 1991) fit well the diagnosis of Ficobracon , while the latter genus must be synonymised with the genus Syntomernus . Most characters indicated as diagnostic for two latter genera ( van Achterberg and Weiblen 2000) show an overlap. The only exception is the difference in the setosity of mesoscutum (the median lobe of mesoscutum medially setose in Syntomernus and glabrous in Ficobracon ), but this character is not considered strong enough to warrant generic status of Ficobracon . In addition, members of the species attributed here to the genus Syntomernus parasitise ecologically similar hosts. Braconid wasps of the asphondyliae species group attack cecidomiid gall midges ( Maetô 1991; Matsuo et al. 2016), Syntomernus shoreatus van Achterberg & Ng, 2009 uses larvae inside dipterocarp fruits ( van Achterberg et al. 2009), the members of Ficobracon have been reared from fig syconia ( van Achterberg and Weiblen 2000; Wei et al. 2013) and Syntomernus kashmirensis (Maqbool, Akbar & Wachkoo, 2018), comb. nov. is known to be phytophagous on the syconium tissues ( Maqbool et al. 2018). The main character separating Syntomernus from Bracon is the presence of anterolateral areas on third metasomal tergite. The full diagnosis of the genus is presented below.

Diagnosis.

Head transverse, its width (dorsal view) 1.7-2.1 × its median length, with transverse diameter of eye 1.7-3.0 × longer than temple. Clypeus without or with weak dorsal carina, clypeal sulcus absent, dorsal clypeal margin sharp or smoothened. Vertex without mid-longitudinal sulcus. Malar suture absent or weakly impressed. Hind margins of eye and temple (in lateral view) more or less broadened downwards.

Antenna. Dorsal side of scape (lateral view) longer than its ventral side. Antennae with elongate segments, first flagellomere 2-4 × longer than its apical width, middle and penultimate flagellomeres 1.7-2.5 × longer than wide.

Mesosoma 1.1-1.5 × longer than its maximum height. Median lobe of mesoscutum evenly setose or setose only on notauli and posteriorly. Notauli usually deep anteriorly, smoothened or absent and not united posteriorly. Precoxal sulcus absent or vaguely impressed. Mesopleural pit weak or almost indistinct. Mesepimeral sulcus smooth or weakly crenulate, metapleural sulcus smooth. Propodeum with simple and high mid-longitudinal keel developed at least in its apical half and with mid-longitudinal impression in its basal half.

Legs. Hind tibia without subapical row of thick setae (at most with two thick setae subapically). Claws with moderately large, not protruding (rounded) or angularly protruding (acute or blunt) basal lobe.

Wings. Angle between veins C+SC+R and 1-SR ca. 50-70 degrees. Marginal cell of fore wing not shortened, 7-24 × longer than distance from its apex to apex of wing. Vein SR1 distinctly elongate. Vein 3-SR 0.22-0.42 × as long as vein SR1, 0.75-1.50 × as long as vein 2-SR. Vein 1-SR+M more or less curved anteriorly. Hind wing with basally evenly setose membrane. Vein 2-1A of hind wing absent or very short.

Metasoma with six coarsely sculptured tergites. First metasomal tergite with distinct, often deep crenulate mid-longitudinal impression and more or less developed dorsal and dorsolateral carinae. Second metasomal tergite without anterolateral, posteriorly diverging grooves; with dorsolateral impressions more or less deep, crenulated, usually with strong posteriorly converging carinae along their proximal margin. Median area of second metasomal tergite elongate-triangle or longitudinal, with sharp margin. Spiracle of second metasomal tergite located in middle or behind middle of tergite. Suture between second and third tergites deep and curved. Anterolateral areas of third tergite always developed, large and separated by crenulate suture. Apical margins of third to sixth tergites thick, with deep crenulate transverse subapical grooves. Ovipositor sheath 1.4-3.6 × longer than hind tibia, 0.4-1.0 × as long as fore wing. Apex of ovipositor with developed nodus and ventral serration.

A key to the species of the genus Syntomernus from Eastern Palaearctic is presented below. Syntomernus codonatus and S. rhiknosus from the Oriental part of China were also included there while five species described in Chen and Yang (2006) could not be included because the types were not available, and the descriptions are insufficient for inclusion.

Figures

Figures 157 - 166. Syntomernus pusillus Enderlein, 1920 (159 - 162 lectotype, MIIZ) and S. sunosei (Maeto, 1991) (163 - 167 holotype of Bracon flaccus Papp, 1996, HNHM) 157 habitus, lateral view 158, 164 head, front view 159, 163 head, dorsal view 162, 160 propodeum and first-third metasomal tergites, dorsolateral view 161 hind tarsus 165 habitus, dorsal view 166 propodeum and first-third metasomal tergites, dorsal view 167 first metasomal tergite, dorsal view. Scale bars: 1 mm (157, 165); 0.5 mm (158 - 164, 166); 0.25 mm (167).

Figures 127 - 133. Syntomernus flavus sp. nov. (127 - 131 holotype, NIBR 132, 133 paratype, female, SMNE) 127 habitus, lateral view 128 head, front view 129 base of antenna 130 head and mesosoma, lateral view 131 head, dorsal view 132 head, ventrolateral view 133 propodeum, dorsal view. Scale bars: 1 mm (127); 0.5 mm (128 - 132); 0.25 mm (133).

Figures 142 - 152. Syntomernus scabrosus sp. nov. (holotype, NIBR) 142 habitus, lateral view 143 head, front view 144 head, lateral view 145 head, ventrolateral view 146 head, dorsal view 147 mesosoma, lateral view 148 hind tarsus 149 first metasomal tergite 150 apex of antenna 151 apex of hind tarsus 152 apex of ovipositor. Scale bars: 1 mm (142); 0.5 mm (143 - 149); 0.25 mm (150 - 152).

Figures 168 - 178. Syntomernus tamabae (Maeto, 1991) (168 - 173 female, ZISP) and S. asphondyliae (Watanabe, 1940) (174 - 178 paratype, EIHU) 168 fore wing 169, 175 head, front view 170, 174 head, dorsal view 173, 178 metasoma, dorsal view 172 hind tarsus 171, 177 first metasomal tergite, dorsal view 176 habitus, lateral view. Scale bars: 1 mm (168, 176); 0.5 mm (169 - 175, 178); 0.25 mm (177).

Figures 153 - 156. Syntomernus scabrosus sp. nov. (holotype, NIBR) 153 wings 154 mesosoma, dorsal view 155 metasoma, dorsal view 156 metasoma, dorsolateral view. Scale bars: 1 mm (153, 156); 0.5 mm (154, 155).

Figures 134 - 141. Syntomernus flavus sp. nov. (134 - 136 holotype, NIBR 139 - 141 male paratype, SMNE) 134 wings 135 hind tarsus 136 second and third metasomal tergites, dorsal view 137 apex of ovipositor 138 first and second metasomal tergites, dorsolateral view 139 habitus, lateral view 140 metasoma, dorsolateral view 141 head, front view. Scale bars: 1 mm (134, 139); 0.5 mm (135 - 138, 140, 141); 0.25 mm (137).