Eleganesia minuta (Yasumatsu, 1955) Liao & Terayama & Eguchi, 2022

Liao, Hauchuan, Terayama, Mamoru & Eguchi, Katsuyuki, 2022, Revision of Taiwanese and Ryukyuan species of Pristepyris Kieffer, 1905, with description of a new species (Hymenoptera, Bethylidae), ZooKeys 1102, pp. 1-42 : 1

Eleganesia minuta (Yasumatsu, 1955) comb. nov.

Figs 14 , 15 , 16 , 17 , 18

Pristocera minuta Yasumatsu, 1955: 246. Holotype (male, KUF), type loc.: Sobosan, Prov. Bungo, Kyusyu, Japan. Acrepyris minutus : Terayama, 1996: 595 (genus transfer). Pristepyris minutus : Azevedo et al. 2018: 104 (genus transfer). Comb. nov.

Apenesia takasago Terayama, 1996: 143, figs 15-18. Holotype (male, NSMT), type loc.: Tokkasha, Nantou Hsien, Taiwan. Pristepyris takasago : Azevedo et al. 2018: 104 (genus transfer). Syn. nov.

Male diagnosis.

TL ≈ 3.3-5.5 mm. HL/HW × 100 = 98-109. Frons and vertex almost smooth and shining or with shallow foveolae, of which intervals are smooth and shining and wider than diameter of foveolae. Anterior clypeal margin nearly straight. Mandible with four apical teeth. Transverse pronotal carina absent. Cervical pronotal area in lateral view gently rounded. LP/WP = 1.30-1.44. Metapostnotal median carina distinct, but incompletely reaching posterior transverse margin. Tergum II without longitudinal ridge and sulcus, sternum II with longitudinal median carina. Hypopygium with almost straight apical margin. Aedeagus with developed ventral and dorsal valves; apical lobe reduced.

Female diagnosis.

TL = 3.7 mm. HL/HW × 100 = 139. Frons and vertex with foveolae (ca. 0.01 mm in diameter), of which intervals are imbricate; intervals in lateral part of frons as wide as or narrower than diameter of foveolae; intervals in vertex and median part of frons wider than diameter of foveolate. Median portion of clypeus roundly produced anteriad. Compound eye less developed. Mandible with four teeth. Transverse pronotal carina absent. Cervical pronotal area in lateral view gently rounded. Dorsal area of pronotum, mesoscutellum, mesopleuron and dorsomedian face of metapectal-propodeal complex imbricate. Dorsal area of pronotum, mesoscutellum, mesopleuron and dorsolateral face of metapectal-propodeal complex with spare foveolae. Tergum II without longitudinal ridge and sulcus.

Male description.

Full description was given by Yasumatsu (1955) and Terayama (2006). Additional information as below.

Head. HL/HW × 100 = 98-109 (100 in holotype of P. minuta ). Frons and vertex almost smooth and shining or with inconspicuous foveolae (ca. 0.01-0.02 mm in diameter, Fig. 15A ) or shallow foveolae (ca. 0.02-0.04 mm, Fig. 15B ), of which intervals are smooth and shining and wider than diameter of foveolae. Occipital carina present. Median portion of clypeus shortly produced anteriad; median clypeal carina moderately distinct, not reaching anterior margin; anterior clypeal margin nearly straight medially. Compound eye large and convex, with sparse thin erect setae. Mandible with four teeth.

Mesosoma. Pronotum without transverse pronotal carina; cervical pronotal area in lateral view round; dorsal area smooth and shining, or with sparse, inconspicuous or shallow foveolae. Mesopleuron elongate; anterior, upper and lower fovea distinct; acropleural area smooth and shining, with inconspicuous foveolae; mesopleural pit absent. Mesodiscrimen concave, without median carina. Metasternum with metafurcal pit. Lateral face of metapectal-propodeal complex obliquely rugose in marginal area and irregularly rugose in central area. Metapectal-propodeal complex in dorsal view with lateral margins subparallel and slightly convex; LP/WP = 1.30-1.44 (1.30 in holotype of P. minuta ); metapostnotal median carina distinct, but incompletely reaching posterior transverse margin; submedian rugae irregularly running; sublateral margin distinct, but short, incomplete posteriorly; posterior transverse margin distinct; dorsomedian face weakly rugoso-scabrous; dorsolateral face smooth and shining; median portion of propodeal declivity with transversely rugoso-scabrous. Forewing with long R12v vein and R2 flexion line, of which the latter is shorter than 1M2 flexion line (arrows in Fig. 15F ), without 2M12 flexion line. Hindwing with four distal hamuli. Tarsal claws bifid, with thin and curved apical teeth; basal one very short.

Metasoma. Tergum II without longitudinal ridge and sulcus; sternum II with longitudinal median carina. Hypopygium with very long spiculum, with almost straight apical margin; apicomedian part thickened which is visible as a small triangular region; outer face of apicomedian part with relatively dense setae; membrane developed between spiculum and S9ala (Fig. 17A ), without thickened margin. Gonostipes thin and glabrous, fused to harpe in dorsal portion. Harpe in ventral view elongate-spatulate, slightly curved inward, with blunt apex, entirely covered with setae which increase in length toward apex; median basal portion with concavity which accommodates digitus and cuspis. Subbasal part of volsella with seta-bearing area which is almost as long as cuspis. Cuspis elongate-lobate and straight, extending posteriad, with several long setae at the apex. Digitus extending laterad, curled. Aedeagus with reduced apical lobe; dorsal lobe large; ventral lobe elongated, with large lobate projection produced ventrally in posterior portion (arrow in Fig. 17D, F, H ).

Female description.

Female of this species was recognized for the first time by collecting a male and female pair in copulation.

Color. Body light brown; mandible, antenna and legs as same as or lighter than body.

Head. Head capsule with posterior margin very weakly incurved, with posterolateral corner round; HL/HW × 100 = 139. Occipital carina present. Frons and vertex foveolate (ca. 0.01 mm in diameter), with intervals imbricate; intervals in lateral part of frons as wide as or narrower than diameter of foveolae; intervals in vertex and median part of frons as wide as or wider than diameter of foveolae. Clypeus imbricate; median portion roundly produced anteriad; median longitudinal carina reaching anterior clypeal margin which is slightly incurved medially (Fig. 18C ). Compound eye less developed. Mandible with four teeth. Antennomere I (excluding the basal condylar bulb) 3.1 × as long as maximum width; antennomere I:II:III = 27:8:6 in length; antennomere II 0.9 × as long as maximum width, narrowed and bent in basal part; antennomere III-XII each 0.72-0.78 × as long as maximum width, elongate-cylindrical; antennomere XIII (terminal) 1.7 × as long as maximum width, with round apex.

Mesosoma. Pronotum with anterior flange extending anteriad beyond anterior margin of propleuron; cervical pronotal area in lateral view gently round; dorsal area subtrapezoidal, with weakly incurved posterior margin, with inconspicuous foveolae of which intervals are imbricate and wider than diameter of foveolae; transverse pronotal carina absent; LPD/WPD = 1.36. Mesoscutum overlain by posteromedian portion of pronotum. Mesoscutellum trapezoidal, 0.72 × as long as maximum width, weakly imbricate, with a few inconspicuous foveolae. Mesopleuron elongate and imbricate; anterior, upper and lower depressions absent; mesopleural pit absent. Lateral face of metapectal-propodeal complex imbricates entirely. Metapectal-propodeal complex in dorsal view weakly constricted behind propodeal spiracles and then widened again posteriad, without any distinct carinae which subdivide dorsal face; LP/WP = 2.16; dorsomedian face smooth and shining; median portion of propodeal declivity weakly transversely rugoso-scabrous.

Metasoma. Tergum II without longitudinal ridge and sulcus.

Material examined.

Japan: Tokyo. 4 males ( JT200820 _01, 05-07); Minami-osawa , 35°37'11"N, 139°12'03"E, 154 m alt. HauChuan Liao leg. (sweeping); 20/VIII/2020 . 1 female, Miyake-jima ; Kentaro Tsujii leg.; 25/VIII-22/IX/2012 . Yakushima. 2 males ( JK210921 _05, 07); Ohko-no-taki, 30°17'48"N, 130°24'51"E, 16 m alt. HauChuan Liao leg. (sweeping); 22/IX/2021 . Okinawa-Hontou. 1 male ( JO170808 _05); Mt. Nago , 26°35'58"N, 128°01'09"E, 181 m alt. HauChuan Liao leg. (sweeping); 10/VIII/2017 . 2 males ( JO190717 _13, 15); Kunigami Vil. , 26°44'41"N, 128°13'10"E, 316 m alt. HauChuan Liao leg. (sweeping); 19/VII/2019 . Amami-Oshima. 1 male ( JA170808 _13); Mt. Yuwan , 28°16'13"N, 129°19'26"E, 44 m alt. HauChuan Liao leg. (sweeping); 16/VIII/2017 . Ishigaki - jima. 3 males ( JI170808 _28, 31, 35), Mt. Omoto , 24°26'31"N, 124°05'56"E, 93 m alt. HauChuan Liao leg. (sweeping); 12-13/VIII/2017 . Iriomote - jima. 2 males (JIR190717_49, 54), Tropical Biosphere Research Center , 24°23'48"N, 123°48'11"E, 33 m alt. HauChuan Liao leg. (sweeping); 27-28/VII/2019 . Taiwan: N. Taiwan. 3 males (TNT180629_03, 04, 09), Mt. ShiZaiTou, New Taipei City, 24°54'14"N, 121°29'46"E, 778 m alt. HauChuan Liao leg. (sweeping); 29/VI/2018 . 5 males (TNT180706_01, 04, 06-08), Mt. Ta Tung , New Taipei City, 24°52'53"N, 121°34'07"E, 602 m alt. HauChuan Liao leg. (sweeping); 6/VII/2018 . C. Taiwan. 2 males ( TN181022 _40, 47); Sun Moon Lake , Nantou County, 23°50'57"N, 120°56'16"E, 92 m alt. HauChuan Liao leg. (sweeping); 23/X/2018 .

Taxonomic remarks.

Due to the new combination of " Pristepyris minutus " to the genus Elganesia , the "Key to Taiwanese and Ryukyuan species of the genus Eleganesia , based on male morphology" given in Liao et al. (2021) is updated and given as Appendix 1.

The holotype of " Pristepyris takasago " was unable to be discriminated morphologically from E. minuta (including the holotype). Therefore, the former is herein synonymised under the latter.

In the present phylogenetic tree (Fig. 3 ), E. minuta was subdivided into three (or four) lineages, i.e. Lineage “X” from the Kanto area of Japan to Okinawa-Hontou; “Y” from Ishigaki-jima to Taiwan and “Z” from Taiwan. The lineages also showed differences in the shape of the lobate extension of the ventral valve of aedeagus (Lineage X as in Fig. 17C, D; Y as Fig. 17E, F; Z as Fig. 17G, H ). However, there was no remarkable difference among them in external morphology and hypopygium (excluding weak variation in head sculpture as seen in Figs 14A , 15A, B , 16A ) and also no differences in the 28S sequence (Table 2 ). As the lineages were parapatric or allopatric in the area of Taiwan and the Ryukyus, in the present study, the Lineage X, Y and Z are conspecific and treated as E. minuta . However, it is also possible that further taxon sampling and integrative taxonomy may reveal several cryptic species within E. minuta and determine one of them as " E. takasago " (see also “Discussion”).

Distribution and habitat.

Hokkaido to Ryukyus in Japan ( Terayama 2006), northern South Korea ( Lim et al. 2011), northern and central Taiwan; evergreen broadleaf forest.

Figures

Figure 3. ML tree based on the 28 S + COI dataset (1,075 bp in length). Ultrafast bootstrap (UFB), SH-aLRT and posterior probability (pp) values are given beside the nodes. The values were omitted when UFB <95, SH-aLRT <80 and pp <0.90. Tips are labelled with specimen ID. Tokyo, Tokyo Metropolis; Yakushima, Yakushima Island; Amami, Amami-Oshima Island; Okinawa, Okinawa-Hontou Island; Irabu, Irabu-jima Island; N. Taiwan, Northern Taiwan; C. Taiwan, Central Taiwan; E. Taiwan, Eastern Taiwan; S. Taiwan, Southern Taiwan.

Figure 14. Eleganesia minuta comb. nov., male, holotype A head in full-face view B antenna (right) C mandible D mesosoma in lateral view E mesosoma in dorsal view F Forewing G hindwing. Scale bars: 0.5 mm.

Figure 15. Eleganesia minuta comb. nov., male A, C-H JO 190717 _ 13 B JIR 190717 _ 54 A, B head in full-face view C antenna (left) D mandible E mesosoma in lateral view F mesosoma in dorsal view G forewing H hindwing. Scale bars: 0.5 mm.

Figure 16. " Pristepyris takasago ", male, holotype A head in full-face view B antenna (right) C mandible D mesosoma in lateral view E mesosoma in dorsal view F forewing G hindwing. Scale bars: 0.5 mm.

Figure 17. Eleganesia minuta comb. nov., male genitalia A, C (JO 190717 _ 13) from Okinawa-Hontou Island B (holotype) D (JA 170808 _ 13) from Amami-Oshima Island E (JI 170808 _ 31) F (JI 170808 _ 35) from Ishigaki-jima Island G (TNT 180706 _ 01) H (TNT 180706 _ 06) from Taiwan A hypopygium B, C, E, G genitalia (and aedeagus) in ventral view D, F, H aedeagus in outer-lateral view; arrows show morphological variation in ventral valve of aedeagus. Scale bars: 0.2 mm.

Figure 18. Eleganesia minuta comb. nov., female A head in full-face view B antenna (left) C mandible D mesosoma in lateral view E mesosoma in dorsal view. Scale bars: 0.2 mm.