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Two new species of Strongylopsis Brauns (Hymenoptera, Ichneumonidae, Pimplinae) from Beijing, and a key to all species
expand article infoShu-Ping Sun, Tao Wang§, Tao Li, Mao-Ling Sheng
‡ National Forestry and Grassland Administration, Shenyang, China
§ Mentougou Forestry Station, Beijing, China
Open Access

Abstract

Two new species of the genus Strongylopsis Brauns, 1896, are described and illustrated, S. propodealis Sheng & Sun, sp. nov. and S. punctata Sheng & Sun, sp. nov., both collected from Mentougou, Beijing, China. An identification key to all known species of Strongylopsis is provided.

Keywords

China, key, new species, Pimplini, taxonomy

Introduction

Strongylopsis Brauns, 1896, a small genus of the tribe Pimplini in the subfamily Pimplinae (Hymenoptera, Ichneumonidae), comprises seven species (Yu et al. 2016) from the Palaearctic Region, of which six from the Eastern Palaearctic Region (two of them also occur in the Western Palaearctic region) (Kuzin 1950; Viktorov 1958; Momoi 1973; He et al. 1996; He and Liu 2013), three from the Western Palaearctic Region (Brauns 1896; Kasparyan 1974). Two species of Strongylopsis have previously been known from China (He et al. 1996; He and Liu 2013).

Kasparyan (1974) first provided an identification key to the species of Strongylopsis. He and Liu (2013) modified the key with descriptions of one new species, which was collected from the area near the southern border of the Eastern Palaearctic part of China. The diagnostic characters of the genus were revised by He and Liu (2013) and Townes (1969).

The hosts of Strongylopsis are still unknown, but other genera of Pimplini are known to be koinobiont endoparasitoids of (predominantly) Lepidoptera and Hymenoptera pupae (Gauld et al. 2002).

In the last ten years the authors have been exploring the forests of Beijing: Mentougou, Fangshan, Yanqing, Pinggu, and have collected large numbers of ichneumonids. In the present research two new species of Strongylopsis, collected in this area, are described.

Material and methods

Institutional abbreviations

GSFGPM General Station of Forest and Grassland Pest Management, National Forestry and Grassland Administration, China

SCAUG Department of Entomology, South China Agricultural University, Guangzhou, China

ZJUH Institute of Insect Sciences, Zhejiang University, Hangzhou, China.

Specimen collection

Specimens were collected with interception traps (IT), as described by Li et al. (2012), in Mentougou forest (Fig. 1), which comprises mixed deciduous angiosperms and evergreen conifers, mainly Betula dahurica Pallas (Betulaceae), Celtis bungeana Blume (Cannabaceae), Platycladus orientalis (L.) Franco (Cupressaceae), Ephedra equisetina Bunge (Ephedraceae) , Castanea spp., Quercus wutaishanica Mayr, Quercus spp. (Fagaceae), Juglans regia L. (Juglandaceae), Larix spp., Pinus tabulaeformis Carr. (Pinaceae), Rubus saxatilis L., Prunus spp., Pyrus spp., Rosa spp. (Rosaceae), Populus spp., Salix spp. (Salicaceae), Acer spp. (Sapindaceae) and Ulmus pumila L. (Ulmaceae).

Figure 1. 

Habitat of Strongylopsis propodealis Sheng & Sun, sp. nov. and S. punctata Sheng & Sun, sp. nov. The forest in Mentougou, Beijing.

Photos of the types of Strongylopsis chinensis He, 1996 and S. xizangensis He & Liu, 2013 (deposited in ZJUH) taken by Dr. Jing-Xian Liu (SCAUG), were checked and compared to the new species by the corresponding author.

Images were taken using a Leica M205A stereo microscope with LAS Montage MultiFocus. Morphological terminology is mostly based on Broad et al. (2018). Type specimens are deposited in GSFGPM, National Forestry and Grassland Administration, China.

Taxonomy

Strongylopsis Brauns, 1896

Strongylopsis Brauns, 1896: 274. Type-species: Strongylopsis anomala Brauns.

Diagnosis

(After Townes 1969; He and Liu 2013). Face (Figs 3, 12) evenly convex, strongly protuberant dorsally in female. Clypeal sulcus present. Upper tooth of mandible slightly longer than lower tooth. Antenna (Figs 2, 11) short and stout, second flagellomere shorter than its width in female. Legs of female stout, outer profile of tibia usually with strong pegs (Figs 2, 11, also see figure in Kuzin 1950: 253). Ovipositor sheath very short, hardly surpassing tip of metasoma. Ventral valve of ovipositor with vertical ridges (Fig. 10).

Figure 2. 

Strongylopsis propodealis Sheng & Sun, sp. nov. Holotype. Female. Habitus, lateral view.

The key (females) of eight species of Strongylopsis is included, the female of S. abdominalis Kasparyan, 1974 is still unknown (Kasparyan 1974; He and Liu 2013).

Key to world species of Strongylopsis (females only)

1 Propodeum without transverse wrinkles, smooth, finely punctate (Fig. 7). Tergites almost entirely black (Fig. 8). Face laterad of a median third polished and scarcely punctate (Fig. 3). “Discocubital” cell without ramellus (Fig. 2). Hind tarsus (Fig. 2) dark brown S. propodealis Sheng & Sun, sp. nov.
Propodeum with transverse wrinkles dorsally (Fig. 17). Other characters not entirely as above 2
2 Metasomal tergites almost entirely black (Fig. 8) 3
At least metasomal tergites 2 and 3 red (Fig. 18) 5
3 Hind and middle femora black; hind tibia blackish brown. 1 m-cu with ramellus on anterior end. Malar space 1.5 as long as basal width of mandible S. xizangensis He & Liu, 2013
Hind and middle femora reddish brown; hind tibia pale rufous. Ramellus in fore wing present or absent 4
4 Fore wing hyaline, radial cell weakly darkened along anterior margin. 1 m-cu with ramellus on anterior end. Malar space 0.60–0.95 as long as basal width of mandible S. belua Kuzin, 1950
Fore wing evenly hyaline. 1 m-cu without ramellus. Malar space much longer than basal width of mandible S. chinensis He, 1996
5 Face with dense punctures. Head 1.5–1.6 × as wide as length from lower margin of clypeus to upper margin of face (Fig. 12) 6
Face with sparse fine punctures. Head about 1.7–2.0 × as wide as length from lower margin of clypeus to upper margin of face 7
6 Metasomal tergites (1)2–4 red, tergites 5–8 black (Fig. 18) S. punctata Sheng & Sun, sp. nov.
Metasomal tergites all red (except base of tergite 1) S. rufiventris Viktorov, 1958
7 Fore wing dark brown, shorter than metasosma S. victorovi Kasparyan, 1974
Fore wing hyaline, longer than metasosma S. anomala Brauns, 1896

Strongylopsis propodealis Sheng & Sun, sp. nov.

Figures 2, 3, 4, 5–7, 8, 9–10

Diagnosis

Propodeum (Fig. 7) large, evenly convex, carinae almost entirely absent, with even, fine punctures. Propodeal spiracle elongate, 2.5 × as long as maximum width. Metasomal tergites with relatively dense, fine punctures. Second tergite 0.75–0.8 × as long as posterior width. Ovipositor almost straight, ventral valve with 10 strong ridges (Fig. 10). All tergites black.

Description

Body length 8.0–8.5 mm. Fore wing length 5.0–6.0 mm.

Head. Head 1.6 × as wide as length from lower margin of clypeus to upper margin of face. Inner margins of eyes almost parallel. Face (Fig. 3) 1.4–1.5 × as wide as long, shiny, evenly convex, with sparse (upper median portion dense) distinct punctures and yellow brown setae. Clypeal sulcus vestigial. Clypeus 2.6–2.7 × as wide as long, shiny, median portion distinctly convex transversely, dorsal margin and lower lateral portions with yellowish brown setae; apical margin almost truncate. Mandible with large sparse punctures and yellowish brown setae, upper tooth slightly longer than lower tooth. Malar space 1.0–1.1 × basal width of mandible. Gena with sparse fine punctures. Vertex (Fig. 4) smooth, shiny, with fine sparse punctures. Postocellar line 0.8 × as long as ocular-ocellar line; ocular-ocellar line 1.7 × as long as maximum diameter of posterior ocellus. Frons (Fig. 4) evenly slightly concave, median portion with dense even yellowish brown setae. Antenna 1.4–1.5 × as long as mesosoma, with 33 flagellomeres. Ratios of lengths from first to fifth flagellomeres: 7:6:6:5:5. Occipital carina complete, reaching hypostomal carina slightly above base of mandible, distance to base of mandible 0.2 as long as basal width of mandibles.

Figures 3, 4. 

Strongylopsis propodealis Sheng & Sun, sp. nov. Holotype. Female 3 head, anterior view 4 head, dorsoanterior view.

Mesosoma. Lateral concavity of pronotum (Fig. 6) wide, deep, smooth, shiny, anterior margin with dense fine brown setae; dorsoposterior portion with dense fine punctures and brown setae. Epomia absent. Mesoscutum (Fig. 5) almost flat, shiny, anterior portion with fine punctures and yellowish brown setae. Notaulus indistinct. Scutellum almost shiny, with fine sparse punctures. Postscutellum with indistinct fine punctures. Mesopleuron (Fig. 6) with irregular fine punctures. Speculum and its surrounding area smooth, shiny. Upper end of epicnemial carina reaching subtegular ridge. Metapleuron with almost even fine punctures. Juxtacoxal carina absent. Legs stout. Outer profiles of tibiae with strong pegs (Fig. 2). Ratios of length of hind tarsomeres from first to fifth approximately: 3.6:2.8:2.0:1.3:2.2. Claw simple. Fore wing 1.05–1.1 × as long as metasoma, slightly brownish, hyaline. Vein 1cu-a opposite M&RS. Areolet pentagonal, receiving vein 2m-cu approximately 0.6 × distance from vein 2rs-m to 3rs-m. Postnervulus intercepted at lower 0.25. Hind wing vein 1-cu 0.2–0.25 × as long as cu-a. Propodeum (Fig. 7) evenly convex, shiny, with even, fine punctures (anterior and posterior portions almost sparsely punctate). Anterior of median longitudinal carina present as vestige. Propodeal spiracle elongate, 2.5 × as long as maximum width.

Figures 5–7. 

Strongylopsis propodealis Sheng & Sun, sp. nov. Holotype. Female 5 mesoscutum 6 mesosoma, lateral view 7 scutellum, postscutellum and propodeum, dorsal view.

Metasoma. Metasomal tergites (Figs 8, 9) slightly shiny, with even fine punctures. First tergite 1.6–1.7 × as long as apical width, evenly widened posteriorly, anterior portion almost impunctate; spiracle slightly convex, located at anterior 0.35. Second tergite 0.75–0.8 × as long as posterior width. Third tergite approximately 0.6 × as long as posterior width. Fourth tergite approximately 0.5 × as long as posterior width. Hind margin of seventh tergite slightly concave dorsally. Apex of ovipositor sheath slightly beyond apex of metasoma. Ovipositor almost straight, ventral valve with 10 strong ridges (Fig. 10).

Figure 8. 

Strongylopsis propodealis Sheng & Sun, sp. nov. Holotype. Female. Metasoma, dorsal view.

Figures 9, 10. 

Strongylopsis propodealis Sheng & Sun, sp. nov. Female 9 holotype, apical portion of metasoma, lateral view 10 paratype, apical portion of metasoma, lateral view.

Coloration (Fig. 2). Black, except for following: ventral profile of flagellum, apical half of clypeus, subapical portion of mandible, maxillary palpi, labial palpi, tegulae brown to reddish brown. Legs (except coxae black) red; apex of hind tibia and apical portion of each hind tarsomere slightly dark brown. Posterior margins of tergites slightly brownish. Pterostigma and veins dark brown.

Male

Unknown.

Etymology. The specific name is derived from the large, oblong, smooth propodeum (Fig. 7).

Material examined. Holotype: China • ♀; Beijing, Xiaolongmen, Mentougou; 23.VI.2012; IT by Shi-Xiang Zong. Paratypes: China • 1♀; same data as for holotype except 16.VI.2009. • 3♀♀; same data as for holotype except 8–30.VI.2012; IT by Tao Wang, Shi-Xiang Zong. • 2♀♀; same data as for holotype except 28–29.VI.2013.

Host

Unknown.

Distribution

China.

Differential diagnosis

The new species is similar to Strongylopsis chinensis He, 1996, but can be distinguished from the latter by the following combination of characters: frons without median carina; fore wing vein 1cu-a opposite M&RS; areolet pentagonal, receiving vein 2m-cu approximately 0.6 × distance from vein 2rs-m to 3rs-m; propodeum without wrinkles, without median longitudinal concavity; first tergite 1.6–1.7 × as long as posterior width; apical half of clypeus reddish brown. Strongylopsis chinensis: frons with median carina; vein 1cu-a distal of M&RS; areolet quadrate, receiving vein 2m-cu approximately 0.72 × distance from vein 2rs-m to 3rs-m; propodeum with transverse wrinkles, with median longitudinal concavity; first tergite 1.45 × as long as apical width; clypeus entirely black.

Strongylopsis punctata Sheng & Sun, sp. nov.

Figures 11, 12–14, 15–17, 18

Diagnosis

Face (Fig. 12) with dense punctures and yellow brown setae. Occipital carina reaching hypostomal carina distinctly above base of mandible, distance to base of mandible 0.5 as long as basal width of mandible. Fore wing vein 1cu-a distal to M&RS by 0.3 × length of 1cu-a. Areolet quadrate, receiving vein 2m-cu approximately 0.7 × distance from vein 2rs-m to 3rs-m. Median area of propodeum (Fig. 17) with fine transverse wrinkles, laterally with fine punctures. Posterior portion of first tergite, tergites 2–3 and anterior portion of tergite 4 red to brownish red.

Figure 11. 

Strongylopsis punctata Sheng & Sun, sp. nov. Holotype. Female. Habitus, lateral view.

Description

Body length 11.5–12.0 mm. Fore wing length 8.5–9.0 mm.

Head. Head 1.6 × as wide as length from lower margin of clypeus to upper margin of face. Inner margins of eyes slightly convergent ventrally. Face (Fig. 12) 1.2–1.3 × as wide as long, shiny, evenly convex, with dense punctures (in lateral portion punctures sparser than upper median portion) and yellow brown setae. Clypeal sulcus weak, as vestige. Clypeus 2.5–2.6 × as wide as long, shiny, subbasal portion distinctly convex transversely, with sparse yellow brown setae; apical margin almost truncate. Mandible with sparse punctures and yellowish brown setae, upper tooth slightly longer than lower tooth. Malar space 1.1–1.2 × as long as basal width of mandible. Gena with sparse irregular fine punctures. Vertex (Fig. 13) smooth, shiny, with sparse punctures. Stemmaticum with relatively dense punctures. Postocellar line 0.9 × as long as ocular-ocellar line. Ocular-ocellar line 1.4–1.5 × as long as maximum diameter of posterior ocellus. Frons (Fig. 13) slightly concave, with dense brown setae and weak median longitudinal sulcus. Antenna stout, with 36–37 flagellomeres. Ratios of lengths from first to fifth flagellomeres: 10:8:8:7:7. Occipital carina complete, reaching hypostomal carina distinctly above base of mandible, distance to base of mandible 0.5 as long as basal width of mandible.

Figures 12–14. 

Strongylopsis punctata Sheng & Sun, sp. nov. Holotype. Female 12 head, anterior view 13 head and mesoscutum dorsal view 14 pronotum, lateral view.

Mesosoma. Lateral concavity of pronotum (Figs 14, 15) wide, smooth, shiny, lower anterior and dorsoposterior portions with distinct punctures and brown setae; subdorsal-median and lower posterior portions with distinct transverse wrinkles. Epomia vestigial. Mesoscutum (Fig. 13) almost flat, shiny, with fine punctures and yellowish brown setae. Notaulus indistinct. Scutellum almost shiny, with fine punctures. Postscutellum transverse, slightly convex, with indistinct fine punctures. Mesopleuron (Fig. 15) with even fine punctures; speculum and its surrounding area smooth and shiny. Upper end of epicnemial carina almost reaching to subtegular ridge. Metapleuron with even, fine punctures. Juxtacoxal carina absent. Legs stout. Outer profiles of tibiae with strong pegs (Fig. 11). Ratios of length of hind tarsomeres from first to fifth approximately: 3.6:2.4:1.8:1.0:2.0. Claw simple. Fore wing 1.2–1.3 × as long as metasoma, brownish, hyaline. Vein 1cu-a inclivous, distal to M&RS by 0.3 × length of 1cu-a. Areolet quadrate, receiving vein 2m-cu approximately 0.7 × distance from vein 2rs-m to 3rs-m; postnervulus intercepted at lower 0.2–0.25. Hind wing vein 1-cu 0.2 × as long as cu-a. Propodeum (Fig. 17) evenly convex, shiny, median area with irregular fine wrinkles, lateral areas with fine punctures; posteromedian portions almost smooth, sparsely punctate. Median longitudinal carina present as vestige anteriorly. Propodeal spiracle elongate, 2.3 × as long as maximum width.

Figures 15–17. 

Strongylopsis punctata Sheng & Sun, sp. nov. Holotype. Female 15 mesosoma, lateral view 16 fore wing 17 scutellum, postscutellum and propodeum, dorsal view.

Metasoma. Metasomal tergites (Fig. 18) with even, fine punctures, evenly widened from base to fifth tergites. First tergite 1.5–1.6 × as long as posterior width, evenly widened posteriorly, anterior portion weakly punctate; spiracle slightly convex, located at anterior 0.3. Second tergite 0.8–0.9 × as long as posterior width. Third tergite 0.65–0.7 × as long as posterior width. Fourth tergite 0.55–0.60 × as long as posterior width. Lateral sides of fifth tergite parallel. Apex of ovipositor sheath slightly beyond apex of metasoma.

Figure 18. 

Strongylopsis punctata Sheng & Sun, sp.n. Holotype. Female. Metasoma, dorsal view.

Coloration (Fig. 11). Black, except for following: ventral profile of flagellum, apical half of clypeus, mandible except teeth, maxillary palpi, labial palpi, tegulae, legs except coxae, trochanters and hind tarsus, posterior portion of first tergite, tergites 2–3 and anterior portion of tergite 4 red to brownish red. Hind tarsus black. Pterostigma and veins brownish black.

Male

Unknown.

Etymology

The specific name is derived from the densely punctate face (Fig. 12).

Material examined

Holotype : China • ♀; Beijing, Xiaolongmen, Mentougou; 13.VI.2008; IT by Tao Wang. Paratypes: China • 1♀; same data as for holotype except 23.VI.2012. • 1♀; same data as for holotype except 31.V.2013; Mao-Ling Sheng leg. • 2♀♀; same data as for holotype except 25.VI.–9.VII.2014.

Host

Unknown.

Distribution

China.

Differential diagnosis

The new species is similar to Strongylopsis anomala Brauns, 1896, but can be distinguished from the latter by the following combination of characters: head 1.6 × as wide as length from lower margin of clypeus to upper margin of face; face (Fig. 12) with dense punctures; areolet quadrate; propodeum with distinct transverse wrinkles; second tergite distinctly trapezoidal. Strongylopsis anomala: head at least 1.7 × as wide as length from lower margin of clypeus to upper margin of face; face with sparse fine punctures; propodeum without transverse wrinkles; second tergite square.

Discussion

It is known that the males of Ichneumonids are often more easily caught using interception traps (IT) or Malaise traps. Even though the authors have been exploring the mountains around Beijing for ten years and have collected/ obtained large numbers of ichneumonids, males of Strongylopsis have still not been found.

Maybe the males of Strongylopsis are less distinctive than females, some parts with more or less different coloration from female, but they can be recognised by the strong spine-like setae on the tibia; the gradually narrowed first tergite, with rounded edges and antenna with tyloids.

The males of some ichneumonid groups are not easy to match with females based on morphological characters (Hilpert 1992). For further research on males, as well as females, more accurate assessments will be helped by molecular methods.

Acknowledgements

The authors would like to express their cordial thanks to Drs Gavin R. Broad (NHMUK) and Dmitry R. Kasparyan (ZISP) for reviewing the manuscript. The authors also are deeply grateful to Dr. Jing-Xian Liu (SCAUG) for providing type photos of Strongylopsis chinensis He and S. xizangensis He & Liu. This research was supported by Beijing’s Science and Technology Planning Project (Z191100008519004) and the National Natural Science Foundation of China (NSFC, No. 31110103062, No. 31501887) and by key project of science-technology basic condition platform from The Ministry of Science and Technology of the People’s Republic of China (Grant No. 2005DKA21402).

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