Research Article |
Corresponding author: Sergey A. Belokobylskij ( doryctes@gmail.com ) Academic editor: Elijah Talamas
© 2020 Alexander V. Timokhov, Sergey A. Belokobylskij.
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:
Timokhov AV, Belokobylskij SA (2020) Review of the rare genus Vanhornia Crawford, 1909 (Hymenoptera, Proctotrupoidea, Vanhorniidae) with description of a new species from the Russian Far East. Journal of Hymenoptera Research 79: 57-76. https://doi.org/10.3897/jhr.79.56481
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A brief review of the proctotrupoid genus Vanhornia Crawford is given. A new species, Vanhornia yurii sp. nov. from Primorskiy Territory, Russia, is described and illustrated. Photographic illustrations of Vanhornia eucnemidarum Crawford, 1909 (specimens from USA), V. leileri Hedqvist, 1976 (specimens from the Russian Far East) and V. quizhouensis (He & Chu, 1990) (holotype) are given. An identification key to all known species of Vanhornia is provided.
Eastern Asia, key, new species, new distribution, Proctotrupoidea, Vanhorniidae
The superfamily Proctotrupoidea is a diverse group of poorly studied parasitic Hymenoptera of ancient origin. The concept of Proctotrupoidea has changed considerably over the last few decades. After the exclusion of several taxa, Proctotrupoidea s. str. is considered to include eight extant families. Along with the moderately abundant Proctotrupidae, there are much smaller but morphologically distinct families, namely Austroniidae, Heloridae, Pelecinidae, Peradeniidae, Proctorenyxidae, Roproniidae and Vanhorniidae (
Vanhorniidae is an enigmatic family of proctotrupoid wasps. The only genus of the family, Vanhornia Crawford, 1909, has included until now three extant species in the world fauna. The genus was erected for V. eucnemidarum Crawford, 1909, which is the type species by monotypy (
Members of this genus are medium-sized parasitoids (4.0–6.7 mm) and distinctly differ from other proctotrupoid wasps in a unique set of defining morphological features, namely the strong exodont mandibles, projecting downward and not meeting each other on midline; antennae attached very low on the frons, just above the clypeus; face extremely low; large metasomal carapace consisting of the syntergite (fused T2–T5) and synsternite (fused S2–S5 in females or S2–S6 in males); long exserted ovipositor, turned forward and at rest accommodated in the ventral median groove of the synsternite (
Information of the biology of the genus remains scarce. Originally, the small type series of V. eucnemidarum was obtained from the larval chambers of an unidentified false click beetle (Coleoptera: Eucnemidae) (
Study of materials from different regions of Russia revealed three additional records of Vanhornia. In this paper one of the specimens from the southern Russian Far East is described as a new species, and the other records provide new important information on the distribution of the trans-Palaearctic V. leileri.
The main aim of this study is to describe a new Vanhornia species from Eastern Palaearctic, to review all the known species of the genus of the world fauna, to prepare a new illustrated key for determination of Vanhornia species, and to discuss some of its morphological characters and distribution.
The morphological terminology used in the present study follows Hymenoptera Anatomy Ontology (
Photographs were obtained using a Leica M165 stereomicroscope equipped with a Leica DFC450 camera (Paleontological Institute RAS, Moscow) and with a Canon EOS 70D digital camera mounted on an Olympus SZX10 microscope (Zoological Institute RAS, St. Petersburg). Image stacking was performed using Helicon Focus 5.0. Final plates were prepared in Adobe Photoshop CS6.
The following abbreviations are used: POL, shortest distance between the lateral ocelli; LOL, shortest distance between the lateral ocellus and the median ocellus; OOL, shortest distance between the lateral ocellus and compound eye; OD, maximum ocellar diameter.
The holotype of Vanhornia yurii sp. nov. is housed in the Zoological Institute, Russian Academy of Sciences (St. Petersburg, Russia).
Vanhornia eucnemidarum Crawford, 1909.
Vanhornia eucnemidarum Crawford, 1909
Vanhornia leileri Hedqvist, 1976
Vanhornia quizhouensis (He & Chu, 1990)
Vanhornia yurii Timokhov & Belokobylskij, sp. nov.
Holotype
, ♀, “RUSSIA, Primorskiy kray [Territory], Lazovsk. z-k [Lazovsky Nature Reserve], b. [bukhta = Bay] Proselochnaya, 21–25.VII.2008, Yu. Sundukov [coll.]” (
Female. Body length 3.9 mm; fore wing length 2.6 mm; antenna length 1.5 mm; ovipositor length 2.7 mm.
Head : In dorsal view 1.35 times as wide as its medium length, 1.3 times as wide as maximum width of mesoscutum; in lateral view 1.1 times as high as long; vertex distinctly roundly convex. Head behind eyes (dorsal view) weakly convex in anterior two-thirds, then weakly roundly narrowed. Vertex posteriorly without median longitudinal sulcus. Temple bulging, almost equal to transverse diameter of eye (dorsal view). Eyes suboval, slightly narrowed ventrally, bare. Ocelli weakly enlarged, arranged in obtuse triangle with base (POL) 1.5 times as large as its sides (LOL). POL almost 4.0 times OD, 1.6 times OOL. Occipital carina interrupted dorsally over wide distance, present laterally. Occiput dorsally with effaced vertical median sulcus. Frons distinctly widely convex medially, with small shallow but distinctly rounded submedian depression. Antennal scrobes present as shallow, smooth, subvertical oblique lateral furrows, without marginal carinae delimiting them from the central area of frons. Interantennal process present as obtuse low convex vertical cushion. Clypeal suture distinct and deep. Clypeus narrow and very wide, with two medio-lateral acuminate corners, distinctly concave medially and weakly concave laterally, about 5.0 times as wide as median height. Malar space very short. Temple along its lower margin (between occipital carina and eye) with transverse crenulate narrow furrow. Mandible with four distinct and thick teeth and small additional tubercle on antero-lateral surface; apically two anterior teeth rather acuminate and two posterior teeth rounded and obtuse; anterior tooth distinctly separate from more closely situated three posterior teeth. Clypeus and base of mandibles covered by rather dense long whitish setae. Vertex and temple entirely in distinct but small, numerous and rather dense setiferous punctation; frons finely and sparsely punctate.
Antennae : Thickened, setiform, gradually weakly narrowed apically, 13-segmented, with very dense and short setosity. Scapus widened distally, 1.7 times as long as maximum apical width, about 2.5 times as long as subglobal pedicel. First flagellomere longest and widest, evenly widened towards apex, 2.6 times as long as its maximum width, 1.3 times as long as second flagellomere. Antennomeres A5–A9 elongate, uniform in length. Penultimate segment 2.0 times longer than wide, 0.75 times as long as apical segment; the latter weakly acuminate apically.
Mesosoma : Almost as high as wide, 2.1 times as long as maximum width (dorsal view), 1.9 times as long as maximum height (lateral view). Pronotal collar elongate, rugose-reticulate posteriorly and medially (dorsal view). Netrion almost spindle-shaped, smooth, distinctly delimited by complete and crenulate with rugosity netrion sulcus. Mesoscutum distinctly transverse, 1.5 times wider than medial length, weakly convex, almost entirely distinctly and rather densely (but fine and sparse posteriorly, including between notauli) punctate with short and pale setae. Notauli arcuate, deep, complete throughout, distinctly and rather sparsely crenulate, not widened posteriorly. Parapsidal lines present and narrow. Scutoscutellar (prescutellar) sulcus deep, curved, with seven rather narrow foveae separated by distinct high striae. Scutellum rather large, distinctly narrowed posteriorly, almost as wide anteriorly as its median length, posterior fifth of scutellum separated by deep and distinctly crenulate transverse curved mesoscutellar sulcus. Metanotum (dorsal view) medially with subsquare and coarsely rugose convex area, laterally coarsely and sparsely crenulate with rugosity. Mesopleuron in wide and mainly concave median area (femoral depression) smooth and bare, antero-ventrally with wide crenulation at short distance; mesopleural carina (anterior ridge of mesopleuron) sharp, rugulose-crenulate in antero-dorsal half, extending posteroventrad as low and effaced ridge to postpectal (ventral mesopleural) carina; speculum smooth; mesepimeral sulcus comprised of large subcircular foveae above and smaller transversely elongate foveae below; lower convex longitudinal area of mesopleuron anteriorly distinctly rugulose-punctate, finely and sparsely punctate posteriorly; mesodiscrimen wide, percurrent, foveolate, in sparse and coarse crenulation. Propodeum mostly coarsely reticulate-areolate; basally with two curved short medial keels and two long, oblique, posteriorly converging lateral keels, delimiting three rather small mainly smooth but rugose posteriorly basal areas; with complete high coarse transverse curved keel in posterior 0.4 of propodeum.
Fore wing : About 3.0 times as long as maximum width, entirely in dense and dark setosity. Radial cell distinctly shortened, surpassed by postmarginal vein, 3.5 times as long as maximum width. Costal section of radial cell 1.4 times length of pterostigma, about 1.5 times distance from apex of radial cell to apex of wing. Apical (terminal) abscissa of radial vein (3-Rs) weakly curved basally and almost straight in distal half, 3.0 times as long as preceding abscissa of this vein (2-Rs). Medial cell small and narrow, strongly narrowed distally. Vein cu-a straight and interstitial to vein 1-M.
Legs : Slender. Hind femur distinctly narrowed basally and apically, 4.0 times as long as maximum width. Trochantelli absent on all legs. Tibial spurs short, their formula 1/2/2.
Metasoma : Narrow (dorsal view). Syntergite 2–5 (dorsal view) without any traces of fusion of tergites, 2.4 times as long as its maximum width; basally with high and coarse weakly curved transverse keel, medially and laterally with coarse longitudinal keels in basal quarter of syntergite, with several and rather sparse longitudinal striation on basal 0.2; remaining part of syntergite entirely in rather dense but fine setiferous punctation. Synsternite 2–5 with a percurrent deep, relatively narrow and almost smooth groove on midline, almost entirely in dense and fine setiferous punctation, upper smooth on narrow stripe, posteriorly in narrow area in dense, straight or weakly curved vertical striation. Cowled tergite 6 abruptly deflexed, mostly in sparse and fine setiferous punctation, almost smooth in anterior vertical third; in posterior view, rather narrow, subtriangular shape, strongly narrowed to lower margin and distinctly convex upper, 1.4 times as high as maximum width, with distinct median obtuse and smooth vertical bar. Ovipositor mostly exposed, slender and flexible, its visible part 0.7 times as long as body.
Colour : Body mainly black, metasoma with brown parts. Antenna black; mandibles mostly brown with black teeth; palpi light brown to brown. Legs brown to dark reddish brown, fore and middle tibiae and tarsi and hind tarsus yellow to partly brownish yellow. Tegula dark brown. Fore wing faintly infuscate; sclerotised veins brown; pterostigma black. Ovipositor yellow.
Male. Unknown.
This new species is similar to V. quizhouensis (He & Chu, 1990) from China (Guizhou) (Fig.
The new species is also similar to the North American V. eucnemidarum Crawford, 1909 (Fig.
Vanhornia eucnemidarum Crawford, 1909 (female, specimens from USA) A habitus, dorsal view B body, dorsal view C body, lateral view D antennae, head and mesosoma, ventral view E right mandible, lateral view F head and mesoscutum, dorso-lateral view G head, front view H mesosoma, lateral view I metasoma, dorsal view J metasoma, ventral view K wings.
This species is named in honour of its collector, Dr Yuriy N. Sundukov, a Russian coleopterist and hymenopterist.
(Fig.
According to the illustration (
(
Vanhornia leileri Hedqvist, 1976 (A–F, H–K female G male, specimens from Russian Far East) A habitus, lateral view B right mandible, lateral view C head, dorsal view D head, front view E head, lateral view F antenna G basal part of antenna H head, antero-lateral view I mesosoma, dorsal view J mesosoma, lateral view K metasoma and hind leg, lateral view.
Male (first description). Body length 4.3 mm; fore wing length 3.0 mm. Antennomeres 4 and 5 noticeably and antennomere 6 only slightly modified, with narrow longitudinal ridges ventrally (Fig.
(Fig.
(
1 | Syntergite 2–5 striate in basal 0.7–0.8 (Figs |
V. leileri Hedqvist |
– | Syntergite 2–5 striate in basal 0.2–0.3 (Figs |
2 |
2 | Scutoscutellar (prescutellar) sulcus with seven foveae separated by prominent striae (Fig. |
V. yurii Timokhov & Belokobylskij, sp. nov. |
– | Scutoscutellar (prescutellar) sulcus with five foveae separated by prominent striae (Figs |
3 |
3 | Median longitudinal sulcus on vertex long and almost complete (Fig. |
V. eucnemidarum Crawford |
– | Median longitudinal sulcus on vertex very short and incomplete (Fig. |
V. quizhouensis (He & Chu) |
Vanhornia is a genus of rare and specialised parasitoids of remarkable appearance. Vanhornia is different from all other Proctotrupoidea in having exodont mandibles, which are generally rare in Hymenoptera. Exodont mandibles are characteristic of braconids in the large subfamily Alysiinae, which use them to cut their way out of the hosts’ puparium (
Rather intriguing is the similarity of the mouthparts of Vanhornia with those of some eucnemid larvae (its hosts), in particular those of Melasini, to which Isorhipis ruficornis belongs, also equipped with large, freely movable, exodont mandibles (
Although all species of Vanhornia have exodont mandibles, their shape is substantially different between certain species.
Another morphological character making Vanhornia unique among the Proctotrupoidea is the presence of a netrion, a morphological trait that was not mentioned in the previous original descriptions of species of this genus (
The metasoma and ovipositor of Vanhornia are also very peculiar features. In Vanhornia, the heterogeneity of metasomal segments is especially pronounced among all Proctotrupoidea and is accompanied by the fusion of several sclerites into syntergites and synsternites, respectively. In V. eucnemidarum and V. leileri, the traces of fusion of metasomal tergites are barely discernible as areas with sparser pubescence (Figs
The presence of a set of peculiar morphological features implies a profound biological specialisation. However, biological information on Vanhornia is rather scarce. Vanhornia eucnemidarum is known as a parasitoid of Isorhipis ruficornis in North America (
Species of the genus Vanhornia are found in the Nearctic (V. eucnemidarum) and Palaearctic (V. leileri and V. yurii sp. nov.), and one species (V. quizhouensis) is found in the Oriental region (South China and Thailand). Of these, V. eucnemidarum is the most common. The other species are especially rare, including V. leileri, which has been known to date only from North, West and Central Europe and from the Russian Far East. Therefore, the new records of V. leileri in East Siberia (Krasnoyarsk Territory) and in the Kuril Islands on the one hand expand its range, and on the other hand partly close the huge distribution gap for this species (Fig.
We are very thankful to Prof. Xue-xin Chen and Dr Pu Tang (Hangzhou, China) for the photos of the holotype of Sinicivanhornia quizhouensis, Dr Elijah J. Talamas (Gainsville, USA) for the photos of the specimens of Vanhornia eucnemidarum and useful corrections of the first variant of MS, Dr Alexandr P. Rasnitsyn (Moscow, Russia) for the opportunity to prepare insect images, Dr Yuriy Sundukov (Vladivostok, Russia) and Victor Kolyada (Moscow, Russia) for the material provided for this study, and Dr Pyotr Petrov (Moscow, Russia) for improving the English of the manuscript. Also we are very thankful to the reviewers for their opinion on the MS, some suggestions and corrections.
This work of AVT was performed as part of the Russian State Research Project No. AAAA–A16–116021660101–5. This work was in part supported by the Russian Foundation for Basic Research (project No. 19–04–00027) and Russian State Research Project No. AAAA–A19–119020690101–6 for SAB.