Tymmophorus Schmiedeknecht 1913

Klopfstein, Seraina, 2014, Revision of the Western Palaearctic Diplazontinae (Hymenoptera, Ichneumonidae), Zootaxa 3801 (1), pp. 1-143 : 103-104

Tymmophorus Schmiedeknecht 1913

Type species. Tymmophorus lacustris Schmiedeknecht 1913

Diagnosis. Tymmophorus species can readily be identified by the following combination of characters: spiracles of the second and third tergites on the dorsal parts, notauli strongly impressed, usually only tergite 1 with a distinct transverse impression. Some Syrphophilus species with indications of notauli can be mistaken for Tymmophorus species. However, the notauli of Tymmophorus are very strongly impressed while being indistinct in Syrphophilus .

Face coriaceous and matt, without vertical impressions, in females black with yellow along inner orbits, these sometimes restricted to frons or completely absent, in males black with yellow inner orbits or entirely yellow. Clypeus with apical margin thin, flat or with a basal elevation that makes it concave in profile. Antenna with apical flagellomeres longer than wide, without tyloids and without long setae. Mesoscutum with notauli comparatively long, reaching one third of length of mesoscutum, always deeply impressed; smooth and shining with some weakly to strongly coriaceous areas, or evenly punctate; yellow shoulder marks usually present; mesopleuron entirely smooth and shining or weakly punctate on lower and front half, rarely mostly coriaceous (in T. gelidus Dasch ); epicnemial carina complete ventrally. Propodeum with a full set of carinae enclosing basal, petiolar and lateral areas; propodeal spiracle inconspicuous; scutellum only carinate basally. Fore wing areolet absent; hind wing with 2–4 basal hamuli. Hind tibia orange to brown. Female metasoma dorsoventrally depressed to strongly compressed from apex of fourth segment, tergites with hind margins convex, with subapical transverse impressions sometimes weakly indicated on tergites 1 and 2. First tergite with or without median dorsal carinae, if present, they are widely separated. Second and third tergites with spiracles dorsal, above lateral folds. Metasoma black, tergites 2–5 usually with orange or yellow hind margins, or mainly orange. Ovipositor sheaths 0.3 times as long as hind tibia, parallelsided and fully enclosing ovipositor, basally smooth, apically with dense and conspicuous setae. Males with tergites 9 and 10 fused as a syntergum, sternite 9 about 1.5 times wider than long, emarginated apically, thus forming two lobes, their outer corners rounded.

Phylogeny. The genus Tymmophorus was not recovered as monophyletic by molecular data as T. obscuripes clustered either with Campocraspedon or basal to a clade including the genera Campocraspedon , Syrphophilus and the two other Tymmophorus species. The position of T. obscuripes , however, was unstable, and additional data are needed to clarify the status of this morphologically rather well-defined genus.

Distribution. Holarctic. This is a small genus including the four Holarctic species discussed here, plus three Nearctic and one Eastern Palaearcthic species.

Biology. The only reliable host records come from the genus Platycheirus ( Syrphinae , Bacchini , Townes 1945; Maibach & Goeldlin de Tiefenau 1991).

Key to species

1. Notauli only weakly impressed, without transverse carinulae................................... cf. Syrphophilus sp.

- Notauli very strongly impressed, often with fine transverse carinulae in the impressions and sometimes interrupting yellow shoulder marks, if present............................................................................... 2

2. All coxae and at least most of hind trochanter black. Femora usually extensively marked with black. Metasoma black, at most with orange hind margins of tergites 2 to 4 or 5............................................................... 3

- Fore and mid coxae mostly yellow, hind coxa black with a yellow tip, trochanters yellow. Femora orange, very rarely with some ventral black marks. Metasoma with at least most of tergite 3 orange........................................ 4

3. Mesoscutum smooth and shining between rather sparse punctures. Antenna with 18 to 20 flagellomeres. Mesopleuron mostly smooth but sometimes with some restricted coriaceous sections and weak punctures, especially along epicnemical carina.......................................................................... Tymmophorus obscuripes (Holmgren)

- Mesoscutum with notauli continued as strongly coriaceous bands towards scutellum. Antenna with 15 to 16 flagellomeres. Mesopleuron shiny coriaceous over most of its surface.................................. Tymmophorus gelidus Dasch

4. Female metasoma dorsoventrally depressed, gradually tapered ( Fig. 26 A). Tergite 2 in females as long as basally wide, or at most 1.2 times longer. Orange on metasoma usually covering all of tergites 3, 4 and often 2, and at least part of tergite 5. Antenna usually all orange, often a bit darker dorsally (males can be difficult to identify).................................................................................................... Tymmophorus suspiciosus (Britschke)

- Female metasoma dorsoventrally depressed basally but strongly compressed laterally posterior to segment 4 ( Fig. 26 B). Tergite 2 at least 1.3 times as long as basally wide in females. Metasoma darker, with most of tergite 2 and all of tergite 5 dark. Antenna brown dorsally, orange or brown ventrally (males can be difficult to identify)....................................................................................................... Tymmophorus erythrozonus (Förster)

Figures

FIGURE 26. Metasomas of Tymmophorus species viewed from above. A. Tymmophorus erythrozonus. B. Tymmophorus suspiciosus. Scale bars represent 500 µm.