The remarkable biology of a new species of Gelis Thunberg, 1827 (Ichneumonidae, Phygadeuontinae), a solitary endoparasitoid of fresh eggs of Timarcha (Coleoptera, Chrysomelidae) Author Shaw, Mark R. https://orcid.org/0000-0002-6651-8801 Honorary Research Associate, National Museums of Scotland, Chambers Street, Edinburgh EH 1 1 JF, UK markshaw1945@gmail.com Author Kan, Pieter 295 Chemin de la Croix, Quartier la Ferrage du Ray, 83830 Callas, France Author Kan-van Limburg Stirum, Brigitte 295 Chemin de la Croix, Quartier la Ferrage du Ray, 83830 Callas, France Author Schwarz, Martin Eben 21, A- 4202 Kirchschlag, Austria text Journal of Hymenoptera Research 2021 2021-04-29 82 161 186 http://dx.doi.org/10.3897/jhr.82.64657 journal article http://dx.doi.org/10.3897/jhr.82.64657 1314-2607-82-161 852712E6BBE44791B0C8DD76D2B4CE3C 6E578025F21B5BEFA9D639EE1C71685E 4741719 Gelis timarchae Schwarz, Shaw & Kan sp. nov. Figs 3-9 , 10-13 (type series); Figs 14 , 15-18 (additional material) Material examined. Holotype ( ♀ ) : " France : Var, Callas, La Ferrage du Ray ex Timarcha nicaeensis egg under loose Prunus dulcis bark coll. 15.4.2019 em. 26.10.2019 . P. Kan 660." ( National Museums of Scotland (NMS), Edinburgh) . Paratypes ( 14 ♀ , 15 ♂ ) same location, solitarily ex eggs of Timarcha nicaeensis , various collection and emergence dates in 2019 and 2020, including rearings in culture (see Tables 1 and 2 , where all paratypes are recorded) (NMS, NHMUK, MSC) . Figures 3-9. Female Gelis timarchae sp. nov., 3-6, 8 holotype 7, 9 paratype 3 habitus lateral 4 head dorsal 5 head facial 6 mesosoma dorsal 7 mesosoma lateral 8 metasoma dorsal 9 ovipositor and sheaths. Figures 10-14. 10- 13 male Gelis timarchae sp. nov., paratype 10 habitus lateral 11 head dorsal 12 head facial 13 mesosoma lateral 14 non-paratype female G. timarchae , head dorsal ( Germany ). Additional, non-paratype, material. Germany : Sachsen, Kyffhaeuser Gebirge, Kattenhof, 450 m, 15.iv.1914, leg. Petry (1♀; ZSM); Ebelsbach (1♀; ZSM). Spain : El Coll, 7.iv.1895 (1♀; MNCN). It is intended that a CO1 barcode sequence will be obtained from one of the paratypes (783 in Table 1 ) and deposited in GenBank. Table 1. Rearings and dissections of wild-collected Timarcha eggs harbouring Gelis spp. collected at Callas. The ix-x.2020 emergences were in Edinburgh, where the host eggs had been sent from Callas in early viii.2020. All others emerged in Callas. All dissections were done in Edinburgh: only prepupae that were alive at the time of dissection are included. The 3-digit code is used to relate parent and progeny in collection depositories; all G. timarchae with such a code are paratypes except that 660 is the holotype.
Date Timarcha egg collected Gelis (code) Date emerged or (dissected) Minimum days development
2.ii.2019 ♂ Gelis timarchae (554) 18.iii.2019 46
2.ii.2019 ♂ Gelis timarchae (555) 20.iii.2019 48
15.iii.2019 ♀ Gelis timarchae (657) 16.x.2019 215
15.iii.2019 ♀ Gelis timarchae (659) 25.x.2019 224
15.iii.2019 ♀ Gelis timarchae (660) 26.x.2019 225
12.i.2020 ♀ Gelis timarchae (669) 29.i.2020 17
12.i.2020 ♀ Gelis timarchae (714) 4.v.2020 113
29.i.2020 ♂ Gelis timarchae (767) 20.ix.2020 236
29.i.2020 ♂ Gelis timarchae (771) 22.ix.2020 238
29.i.2020 ♀ Gelis timarchae (778) 6.x.2020 252
29.i.2020 ♀ Gelis timarchae (781) 16.x.2020 262
23.iv.2020 ♂ Gelis timarchae (766) 13.ix.2020 144
23.iv.2020 ♀ Gelis timarchae (772) 23.ix.2020 154
23.iv.2020 ♀ Gelis timarchae (773) 26.ix.2020 157
23.iv.2020 ♀ Gelis timarchae (775) 29.ix.2020 160
23.iv.2020 ♀ Gelis timarchae (777) 5.x.2020 166
23.iv.2020 Gelis timarchae prepupa (23.xi.2020) >215
8.vi.2020 ♀ Gelis proximus 1.vii.2020 23
8.vi.2020 Gelis timarchae prepupa (8.viii.2020) >62
8.vi.2020 Gelis timarchae prepupa (8.viii.2020) >62
8.vi.2020 Gelis timarchae prepupa (8.viii.2020)* >62
8.vi.2020 ♂ Gelis timarchae (765) 11.ix.2020 96
8.vi.2020 ♀ Gelis timarchae (768) 21.ix.2020 106
8.vi.2020 ♀ Gelis timarchae (769) 21.ix.2020 106
8.vi.2020 ♀ Gelis timarchae (776) 29.ix.2020 114
8.vi.2020 ♀ Gelis timarchae (780) 15.x.2020 130
1.xi.2020 ♂ Gelis timarchae (783) 24.xi.2020 24
1.xi.2020 ♂ Gelis timarchae (784) 24.xi.2020 24
*Prepupa still alive on 23.xi.2020 (169 days), gut not voided. Figures 15-18. Female Gelis timarchae sp. nov., non-paratype specimens 15 mesosoma lateral (Germany) 16 metasoma (Germany) 17 mesosoma lateral (Spain) 18 metasoma (Spain). Diagnosis and remarks. In the female sex this species is most similar to Gelis brevis (Figs 19-24 , which include a doubtfully determined specimen) and, because both species are variable with somewhat overlapping characters, they are not always easily distinguished. In G. timarchae the propodeum is less steeply sloping caudally on average; and the second and often third tergites of the metasoma have dense, closely spaced setae with the distance between setae distinctly smaller than the length of setae, while in G. brevis the distance between setae varies from wider to somewhat smaller than the length of setae. In studied specimens of G. brevis from UK (including the type of Pezomachus brevis Bridgman, 1883) and Germany the metasoma has widely spaced setae, though in material from southern Europe the setae are much closer, but still less densely spaced than in southern European material of G. timarchae . The two specimens of G. timarchae seen from Germany have (especially) third tergites with setae distinctly more widely spaced (distance between setae longer on average than length of setae) than in material from southern France and Spain. From this we conclude that in G. brevis , and less distinctly so in G. timarchae , the density of pilosity of the metasoma increases from north to south, as is also the case in western European G. proximus ( Schwarz 2002 ). Further, in both G. timarchae and G. brevis the head is a little more transverse in larger specimens. Because the reared series is so constant and slightly different from other specimens that we regard as G. timarchae , we choose to restrict the type series of G. timarchae to the material originating from T. nicaeensis eggs at Callas. Gelis fossae Schwarz, known only from north-western Africa, also resembles G. timarchae , but G. fossae has a deep furrow between the mesonotum and propodeum, and the hind tibia without setae dorsally. The males of G. brevis and G. fossae are unknown, but the male of Gelis rotundiventris ( Foerster ) resembles that of G. timarchae in many characters (e.g. propodeum evenly sloping from anterior margin, long first metasomal segment, colour). However, G. rotundiventris has the mesoscutum with distinct notaulus, fore wing with 2m-cu nearly straight, propodeum medially distinctly granulate and matt, head behind the eyes weakly narrowed, and second and third tergites of metasoma with widely spaced setae. Figures 19-24. Female Gelis brevis ( 23, 24 tentatively determined) 19 mesosoma lateral (UK) 20 metasoma (UK) 21 mesosoma lateral (Spain, Picos de Europa) 22 metasoma (Spain, Picos de Europa) 23 mesosoma lateral (Mallorca) 24 metasoma (Mallorca). Description. Female . Body length: 3.2-3.7 mm. Apterous. Head . Antenna moderately thick and with 21-23 segments; third segment (without annellus) 2.3-2.7 times as long as wide and 0.8-0.9 times as long as fourth segment. Head mainly granulate and matt; face, frons and temple with very fine and scattered punctation. Clypeus strongly convex, only granulate above and with few distinct punctures placed more or less in a transverse row medially, lower part of clypeus smooth and lustrous. Clypeus with ventral margin depressed and evenly rounded, without tooth. Mandible with teeth of equal length. Malar space without a distinct furrow, but with a line of very fine granulation. Malar space 0.8-1.1 times as long as basal width of mandible. Genal carina joining hypostomal carina behind mandibular base. Head in dorsal view 1.9 times as wide as long. Head behind eyes short and strongly narrowed or sometimes moderately narrowed. Mesosoma mainly granulate and weakly matt, but partly lustrous (e.g. mesopleuron). Mesonotum more or less fused with pronotum, short and 0.5-0.6 times as long as wide, without distinct depression medially. Scutellum very short and not distinctly separated from mesoscutum. Metanotum absent dorsally. Mesonotum and propodeum dorsally with moderately spaced setae. Furrow between mesonotum and propodeum of normal size, not unusually deep. Mesosternum ventrally very short and much shorter than diameter of antenna. In profile upper margin of propodeum not higher than upper margin of mesonotum. Propodeum with horizontal part short, about 0.5 times as long as sloping part. Propodeum sloping rather gently posteriorly, but degree of steepness somewhat variable. Posterior transverse carina present, but widely interrupted medially. Hind femur 4.0-4.3 times as long as wide. Hind tibia somewhat widened and with densely placed setae dorsally. Metasoma . First segment with dorso-lateral carina and ventro-lateral carina present, but rather weak. Second and often third tergites of metasoma with densely spaced setae, their distance distinctly smaller than length of setae on average. Laterotergite of second metasomal tergite moderately wide, about 3.0-3.5 times as long as wide. Ovipositor sheath 0.4-0.5 times as long as hind tibia. Ovipositor slender and straight, with nodus indistinct, its tip 3.8-4.0 times as long as wide and with very weak teeth ventrally. Colour . Black. Orange-brown usually on scape partly or entirely, often pedicel, mandible except teeth, legs partly. Palpi, coxae partly, trochanters partly, fore and mid femora partly, hind femur, fore and mid tibiae often partly, hind tibia subbasally and apically brownish or blackish. Variaton (non-type material). Body length 2.8-3.1 mm. Antenna with 20 segments; third segment (without annellus) 2.0-2.2 times as long as wide. Head in dorsal view 2.0 times as wide as long. Hind femur 3.0-3.5 times as long as wide. In German specimens distance between setae of third metasomal tergite longer than length of setae on average. Narrow caudal margins of first and second metasomal tergites orange-brown. Male. Body length: 3.0-3.5 mm. Macropterous. Head . Antenna slender and with 24-27 segments; third segment (without annellus) 3.9-4.4 times as long as wide and 1.0-1.2 times as long as fourth segment; segments 11-12 with tyloids. Head mainly granulate and matt; face, frons and temple with very fine and scattered punctation or without distinct punctation. Clypeus strongly convex, only granulate above and with few distinct punctures placed more or less in a transverse row medially, lower part of clypeus smooth and lustrous. Clypeus with ventral margin depressed and evenly rounded, without tooth. Mandible with teeth of equal length. Malar space without a distinct furrow, but with a line of very fine granulation. Malar space 0.4-0.5 times as long as basal width of mandible. Genal carina joining hypostomal carina behind mandibular base. Ocelli large. Distance between eye and lateral ocellus (OOL) 0.7-0.9 times diameter of lateral ocellus. Head behind eyes moderately short and moderately narrowed. Mesosoma . Mesoscutum with fine granulation and matt, with very fine and hardly recognisable punctation and with densely spaced setae. Mesopleuron weakly granulate and lustrous with scattered punctation. Metapleuron granulate and matt. Propodeum evenly sloping from anterior margin. Propodeum mainly granulate and matt and partly with rugosity (mainly anteriorly); area superomedia and area postica lustrous and with shallow sculpture. Pleural carina, posterior transverse carina laterally and lateromedian longitudinal carina distinct, but the latter usually very fine anteriorly; other carinae of propodeum absent. Hind femur 5.1-5.8 times as long as wide. Hind tibia weakly widened. Fore wing with pterostigma large and triangular. Marginal cell with RS beyond areolet nearly straight but distally weakly bent. Areolet open with 3rs-m absent. 2m-cu rather long, distinctly sinuate and with two widely separated bullae. Metasoma with first segment rather long and slender, dorso-lateral and ventro-lateral carinae present but rather weak, latero-median carina short and present close to spiracle. Second and third tergites of metasoma with densely spaced setae. Colour . Black. Tegula often brown or orange brown. Orange brown are sometimes postpetiole posteriorly, second tergite of metasoma usually entirely or more rarely only partly, third tergite partly or more rarely entirely, rarely fourth tergite anteriorly, sometimes coxae partly, trochantelli partly, trochanters entirely or partly, femora partly or entirely, fore and mid tibiae entirely or partly, hind tibia partly, fore and mid tarsi often partly. Hind tibia narrowly black basally, often brown subbasally and apically. Tarsi mainly brown. Fore wing with pterostigma blackish and only narrowly white basally. Mandible partly reddish. Palpi varying from mainly orange brown to blackish. Etymology. The name refers to the host genus, meaning "of Timarcha ".