ZOOSYSTEMATICA ROSSICA ISSN 2410-0226 Zoological Institute, Russian Academy of Sciences, St Petersburg ▪ https://www.zin.ru/journals/zsr/ (Online) 0320-9180 Vol. 27(2): 229–233 ▪ Published online 3 December 2018 ▪ DOI 10.31610/zsr/2018.27.2.229 (Print) RESEARCH ARTICLE A new species of the genus Syndipnus (Hymenoptera: Ichneumonidae: Ctenopelmatinae: Euryproctini) with unusually depressed metasoma Новый вид рода Syndipnus (Hymenoptera: Ichneumonidae: Ctenopelmatinae: Euryproctini) с необычной сплющенной дорсовентрально метасомой D.R. Kasparyan Д.Р. Каспарян Dmitriy R. Kasparyan, Zoological Institute, Russian Academy of Sciences, 1 Universitetskaya Emb., St Petersburg 199034, Russia. E-mail: [email protected] Abstract. A new species of the subfamily Ctenopelmatinae, Syndipnus depressus sp. nov. with strong dorsoventral compression of the metasoma, is described from Poland. Similarity of the new species to two ctenopelmatine species of the tribe Mesoleiini (Mesoleius phyllotomae Cushman, 1933 and M. aceris Shaw et Kasparyan, 2003), endoparasitoids of leaf mining sawflies of the genusHeterarthrus Stephens, 1835 (Tenthredinidae: Heterarthrinae), suggests that the new species may have similar hosts. Резюме. В подсемействе Ctenopelmatinae описан из Польши новый вид Syndipnus depressus sp. nov. с сильно сплющенной дорсо-вентрально метасомой. Сходство нового вида с двумя други- ми видами трибы Mesoleiini (Mesoleius phyllotomae Cushman, 1933 и M. aceris Shaw et Kasparyan, 2003), эндопаразитоидами минирующих пилильщиков рода Heterarthrus Stephens, 1835 (Ten- thredinidae: Heterarthrinae), дает основание предполагать, что новый вид имеет сходных хозяев. Key words: taxonomy, Poland, Europe, West Palaearctic region, Tenthredinidae, Heterarthrinae, new species Ключевые слова: систематика, Польша, Европа, Западная Палеарктика, Tenthredinidae, Heterar- thrinae, новый вид ZooBank Article LSID: urn:lsid:zoobank.org:pub:8A2C4D3A-72AB-4D1C-B493-644C825B2E35 Introduction metasoma. Since the publication of monographs by Schmiedeknecht (1913) and Meyer (1936), a The Holarctic genus Syndipnus Förster, 1869 few additional Palaearctic species have been de- includes 30 species: 7 Nearctic and 23 Palaearctic scribed by Roman & Lack (1934), Habermehl (Yu et al., 2016). The genus may easily be distin- (1935), Teunissen (1953), Kasparyan (2003) and guished from other Ctenopelmatinae genera (ex- Aubert (1998, 2007). A synopsis of the Nearctic cept for the Rhorus mesoxanthus species-group) species was given by Walley (1940, 1945). by the immovably joined (partly fused) tergites 2 All known host records of Syndipnus species and 3, and absence of a glymma in tergite 1 of the are from nematine sawflies (Nematinae: Tenthred- © 2018 Zoological Institute RAS and the Author(s) D.R. Kasparyan. A new species of Syndipnus inidae) with open-living larvae feeding on conifer- Description. Female (holotype). Fore wing ous and deciduous trees and on herbaceous plants 4.0 mm long. Antenna (Fig. 1) with 23 flagel- (Aubert, 2000; Yu et al., 2016). lomeres; flagellum 3.5 mm long, about 0.9 times The aim of this work is to describe a new spe- as long as fore wing; two basal flagellomeres com- cies of Syndipnus from Poland. bined as long as maximum diameter of eye; length of subapical flagellomeres 1.3 times of their width. Material and methods Head weakly and roundly narrowed behind eyes, almost 1.4 times as wide as mesoscutum between The holotype of the new species is deposited in tegulae. Malar space finely granulate, about 0.6 the Zoological Institute of the Russian Academy of basal mandibular width. Face finely scabrous of Sciences, St Petersburg, Russia (ZIN). Morpho- with fine scarce punctures, its central part with logical terminology mainly follows that of Townes thin vertical rugae. Frons granulate, with median (1969, 1970). Taxonomy follows the catalogue polished longitudinal shallow depression, and in TaxaPad (Yu et al., 2016). Layer photographs were lower half with more or less transverse irregular taken in ZIN with a Canon EOS 70D digital cam- rugae. Temple smooth with fine sparse punctures era attached to an Olympus SZX10 stereomicro- and with granulation in its lower part (on cheek). scope, and partially focused images were assem- Pronotum with short epomia obscured (hid- bled with Helicon Focus 6 Pro software. den) by adjacent rugae; dorsolateral area behind epomia smooth and almost impunctate; lower cor- Results ners of pronotum with irregular rugae. Mesoscu- tum smooth with rather superficial moderately Order Hymenoptera large punctures; notauli rather long but not deep; Family Ichneumonidae median lobe of mesoscutum dorsally polished with sparse short setae and with small impunctate Subfamily Ctenopelmatinae area, behind this area (in posterior half) with lon- Tribe Euryproctini gitudinal rugosity and rather coarse punctures. Genus Syndipnus Förster, 1869 Prescutellar groove wide, crenulated with about nine short transverse rugae. Scutellum smooth, Type species: Euryproctus (Syndipnus) mac- moderately punctate, with short dorsolateral ca- rocerus Thomson, 1883; designated by Viereck, rinae. Mesopleuron smooth with sparse fine punc- 1914. tures, with light rugosity on front margin and near subtegular ridge; speculum large. Upper end Syndipnus depressus sp. nov. of prepectal carina almost reaching hind margin (Figs 1–5) of pronotum at its middle. Mesopleural pit as a Holotype. Female; Poland, “Lomna Stac-ja at War- short groove, about 0.25 times as long as meso- szawa, 10.6.1987, byliny”, leg. Ja. Sawoniewicz (ZIN). pleuron. Mesopleural suture before mesepimeron Etymology. The name of the new species refers with about nine deep pits. Metapleuron roughly to strong dorsoventral depression of its metasoma. scabrous with small polished area before front end Comparative diagnosis. The new species can of indistinct pleural carina; submetapleural carina easily be distinguished from all congeners by distinct. Propodeum rugose, with transverse ru- the strongly dorsoventrally depressed metasoma; gosity on basal area and areola; median longitudi- tergites 6 to 8 long and each projecting strongly nal carinae and carinae enclosing laterally apical beyond the preceding tergite (Fig. 2); ovipositor area rather coarse (Figs 3, 4). small, thin, entirely concealed by tergites 7 and Metasoma strongly depressed (Fig. 2), dorsal- 8 (Fig. 5); antenna with only 23 flagellomeres ly with first tergite completely and second tergite (in most congeners usually more than 24 flag- at basal two tenths and widely laterally (except ellomeres; 19–21 flagellomeres only in S. saotis distal two tenths) matt, with thin scabrous sculp- Kasparyan, 2003, but in this species metasoma is ture; following tergites shining, subpolished, with compressed laterally). sparse fine setae (Fig. 4). First tergite 1.25 times 230 ( Zoosystematica Rossica, Vol. 27, No. 2, pp. 229–233 D.R. Kasparyan. A new species of Syndipnus Figs 1–5. Syndipnus depressus sp. nov., female, holotype. 1, head and antenna, lateral view; 2, body, lateral view; 3, mesosoma, dorsal view; 4, propodeum and base of metasoma, dorsal view; 5, apical segments of metasoma, ven- tral view. ( Zoosystematica Rossica, Vol. 27, No. 2, pp. 229–233 231 D.R. Kasparyan. A new species of Syndipnus as long as wide at hind margin; petiole at base mesoxanthus species-group of the genus Rhorus narrow, 0.3 times as wide as posterior width of Förster, 1869, and in Syndipnus (Ctenopelmati- tergite. Second and third tergites confluent, me- nae). Other considerable modifications in the diodorsally without distinct suture between them. structure of metasoma of some Syndipnus species Tergites 6 to 8 long and each projecting strong- perhaps are connected with utilisation of ecologi- ly beyond preceding tergite (Fig. 2). First tergite cally new hosts. In the genus Syndipnus, hosts are without epipleura; tergites 2–8 with epipleurae known for only five or six species and all of them wide, about twice as long as wide, strongly turned are the nematine sawflies (Tenthredinidae: Nem- under; tergites 2 and 3 with epipleurae separated atinae) with larvae living openly on coniferous, from their tergites by distinct crease; and terg- willows and grasses. Syndipnus depressus sp. nov. ites 4–7 with epipleurae without distinct crease. described here differs from congeners and from Spiracles dorsad of creases in tergites 2 and 3, and most other ichneumonids by the strong dorsoven- laterad (on turned margins) in tergites 4–7. Ster- tral depression of the metasoma. By this unusual nites 2–8 strongly sclerotised, with weak median morphological peculiarity and by habitus, the new longitudinal fold on sternites 2 and 3, and without species is similar to two ctenopelmatine species distinct fold on sternites 4–6 (Fig. 5). Ovipositor of the tribe Mesoleiini: Mesoleius phyllotomae small and completely hidden under tergites 7 and Cushman, 1933 and M. aceris Shaw et Kaspary- 8 (Figs 2, 5). an, 2003. Both are endoparasitoids of leaf-mining Antennae blackish. Head and mesosoma black. sawflies of the genus Heterarthrus (Tenthredini- Clypeus and mandible yellow; palpi dark brown, dae: Heterarthrinae) whose larvae feed on Betula fourth and (or) third maxillary palpomeres yel- Linnaeus, 1753 and Acer Linnaeus, 1753, respec- lowish. Small sclerite between hind corner of tively. These data can be considered as clues for pronotum and tegula whitish yellow; tegula yel- possible trophical links of S. depressus sp. nov. lowish, translucent. Pterostigma brownish, pale with similar concealed hosts