© Entomologica Fennica. 13 June 2008 New species of Orthocentrinae (Hymenoptera: Ichneumonidae) from Finland Andrei E. Humala Humala, A. E. 2008: New species of Orthocentrinae (Hymenoptera: Ichneu- monidae) from Finland. — Entomol. Fennica 19: 94–104. Five new species of ichneumonids of the subfamily Orthocentrinae s. l. were dis- covered in Finnish collections. A new genus is proposed for one new species from Southern Finland, Fennomacrus koponeni gen. et sp. n. Its relationships and systematic position are briefly discussed. Four other new species, Plectiscidea aquilonia sp. n., P. fuscifemur sp. n., P. helleni sp.n.andEusterinx (Holome- ristus) fennoscandica sp. n., from Fennoscandia are also described. The hitherto unknown female of Helictes fabularis Rossem is described as well. A. E. Humala, Forest Research Institute, Karelian Centre of the Russian Acad- emy of Sciences. Pushkinskaya St. 11, Petrozavodsk 185910, Russia; E-mail: [email protected] Received 14 June 2006, accepted 30 July 2007 1. Introduction H. Townes, based on the fact that the type spe- cies of the type genus (Plectiscus impurator The subfamily Microleptinae sensu Townes (Hy- Gravenhorst, 1829) belongs to Orthocentrinae, menoptera: Ichneumonidae) was established as proposed a new name for this group – Micro- an independent taxon roughly equivalent to its leptinae (Townes 1958). He placed together with modern usage by A. Förster under the name plectiscines several genera of unclear relation- Plectiscoidae (Förster 1869). He described the ships, admitting that this subfamily was a “waste- majority of recent genera and a lot of species, re- basket group” (Townes 1971). Although some vealing their significant morphological diversity genera, such as Oxytorus, Tatogaster, Acaeni- (Förster 1869, 1871). Some ichneumonids simi- tellus and Microleptes, were later excluded from lar to plectiscines belonging to other subfamilies, the group (and in this connection the subfamily e.g. Ateleute, Polyaulon, Symphylus (=Acrodac- name has changed 3 times during the last 20 tyla), Adelognathus, were included by him in this years), up to now a uniform and generally ac- group as well. On the other hand, many genera cepted classification is missing, and the sub- without a closed areolet in the fore wing, which family still remains insufficiently known, be- are included nowadays in Orthocentrinae, were cause of its high morphological diversity and described by Förster in other groups of ichneu- confusing taxonomy. monids. C. G. Thomson considered plectiscines After several genera were removed, the re- among other Tryphonidae close to ortho- maining ones were treated as the subfamily centrines, and divided them into 4 sections Helictinae (Gupta 1987, Gauld 1991, Dasch (Thomson 1888). He synonymised some of 1992). Resulting from the works of Wahl (1986, Förster’s genera and changed their status to sub- 1990), they were united with the orthocentrines genera for some others. within Orthocentrinae s. l. (Yu & Horstmann ENTOMOL. FENNICA Vol. 19 • New species of Orthocentrinae from Finland 95 1997, Wahl & Gauld 1998), while Cylloceria and Some collections of the Zoological Museum of Allomacrus were removed from other “helic- Uppsala University (UUZM) have been revised tines” into the subfamily Cylloceriinae. The Pa- as well. Morphological terminology mainly fol- laearctic fauna of these two segregated genera lows Gauld (1991). Finnish collecting localities was recently revised (Humala 2002), and two are provided with coordinates using 27°E grid, species, Cylloceria tenuicornis Humala, 2002 biogeographical provinces of East Fennoscandia and Allomacrus subtilis Humala, 2002, were de- are given according to Heikinheimo and Raati- scribed from Finland and Russia. The third genus kainen (1971). Rossemia (= Sweaterella) included in this group was described from the Karelian Republic and the Far East (Humala 1997, Wahl & Gauld 1998). 3. Results and discussion According to the Catalogue of World Ichneu- monidae (Yu & Horstmann 1997) the Ortho- 3.1. Genus Fennomacrus gen. n. centrinae s. l. comprises 31 recent genera, with moderate numbers of species, though the struc- Diagnosis. Fennomacrus can be distinguished ture and composition of the subfamily are still far from all other ichneumonid genera by the follow- from stable. Since that time the genus Kentro- ing combination of features: the wide and flat tryphon was synonymised under Allomacrus clypeus (Fig. 1b); mandibles not twisted, with (Schwarz 2004), genus Epitropus under Adelo- subequal teeth; weak notauli; absence of ste- gnathus, Pantomima under Acrodactyla, Fetialis rnauli; first sternite not fused with tergite, with under Aclastus (Broad 2004) and the genus spiracles before mid-length of segment; compar- Cressonia was transferred to Diacritinae (Wahl & atively short, straight ovipositor; slender legs; Gauld 1998). presence of areolet; fore wing vein 2m-cu with All species for which the biology is known are two bullae; unbroken reclivous nervellus; distinct larval koinobiont endoparasitoids of Diptera sculpture of head and mesosoma. In the structure Nematocera, primarily fungus gnats (Sciaroi- of the first metasomal segment the new genus is dea). Orthocentrines comprise a common and close to the representatives of tribe Cylloceriini conspicuous part of the ichneumonid fauna, espe- Wahl, 1990 (Humala 2003, 2007). Fennomacrus cially in north and temperate regions, where the differs from Allomacrus in the weak notauli and group is particularly species-rich and abundant, straight ovipositor; from Entypoma by the weak but up to now this subfamily is one of the least notauli, straight mandibles, slenderer legs, espe- known within Ichneumonidae. cially femora, straight ovipositor; from Proeli- ator and Plectiscidea by the first metasomal seg- ment with tergite and sternite not fused, presence 2. Materials and methods of glymmae on the first tergite, distinct granulate sculpture on head and mesosoma. For the present research the collections of Fennomacrus is represented by a single Orthocentrinae s. l. stored at the Zoological Mu- known species. The habitus of the genus is illus- seum, Finnish Museum of Natural History of trated in Fig. 1a. Helsinki University, including the collection of To my mind, the genus Allomacrus is much Wolter Hellén (ZMHU), and Department of Ap- closer to Apoclima and Entypoma than to Cyllo- plied Biology of the Helsinki University ceria (Humala 2003), and D. Wahl’s arguments (DABHU) – now part of ZMHU – were studied. for segregation of these two genera (Wahl 1986, Additional material collected during entomologi- 1990) seems not to be convincing, which was cal investigations in the Biosphere Nature reserve confirmed for instance by the synonymy of “Northern Karelia” in 1994–1999 and in some Allomacrus and Kentrotryphon (Schwarz 2004). adjacent territories, stored at the Karelian Re- So this group should be expanded by including search Centre in Petrozavodsk (KRC) and at the other genera, based on the structure of the first Zoological Institute of Russian Academy of Sci- segment of the metasoma. According to Broad ences, St. Petersburg (ZIN), were also used. (2004, pers. com.), Hyperacmus has a close rela- 96 Humala • ENTOMOL. FENNICA Vol. 19 Fig. 1. Fennomacrus koponeni gen. et sp. n., holotype female. – a. Whole insect, lat- eral view. – b. Head, frontal view. – c. Head, dorsal view. Scale bar 0.5 mm. tionship with Orthocentrinae + Cylloceriinae and Etymology. The name is combined from should not be separated from this group. Indi- Fenno – Fennia and macrus – from related genera rectly this was confirmed by edivý and evèík Allomacrus and Stenomacrus. (2003), who reared H. crassicornis Gravenhorst from the fungus gnat Sciophila varia (Winnertz), 3.1.1. Fennomacrus koponeni sp. n. (Fig. 1) inhabiting the fruit body of Hydnum repandum L.: Fr. (Cantharellales, Hydnaceae). As a result Type material. Holotype $, Finland, Sa: Ristiina the new genus is placed together with genera 6826: 502; 4.VII.1980 (M. Koponen leg.) Cylloceria, Hyperacmus, Allomacrus, Rossemia, DABHU. Apoclima and Entypoma, forming the tribe Female (holotype). Body length 2.9 mm; fore Cylloceriini Wahl, 1990 within subfamily Ortho- wing 3.0 mm; antenna slender, 21 flagellar seg- centrinae. ments; first flagellar segment 5.0× as long as ENTOMOL. FENNICA Vol. 19 • New species of Orthocentrinae from Finland 97 wide; second flagellar segment 3.6× as long as after Martti Koponen, who collected the only wide. Head width 1.1× height; face width l.72× known specimen of the genus. height, 0.57× head width, matt, punctate, lateral margins parallel; malar space 1.2× basal width of mandible, with strip of rougher, granulate sculp- 3.2. Genus Plectiscidea Viereck, 1914 ture between eye and mandible, subocular sulcus absent; mandibles not twisted, teeth subequal; Unfortunately the existing key to females of Pa- clypeus small and wide, width 2.4× height (Fig. laearctic Plectiscidea species (Rossem 1991) is 1b), slightly convex at base, remainder flattened almost of no practical use, as very few characters to apex, transversely weakly convex; anterior (mainly the ratio of length of first flagellar seg- tentorial pits small; frons matt; ocular-ocellar dis- ment to its apical width, ratio of length of first tance (OOL) about 1.6× post-ocellar distance metasomal segment to its apical width and ratio of (POL), 1.9× greatest diameter of lateral ocellus; ovipositor length to fore wing length) were used gena well developed, strongly convex, matt, in the key, and it