Syrphoctonus tarsatorius

Klopfstein, Seraina, 2014, Revision of the Western Palaearctic Diplazontinae (Hymenoptera, Ichneumonidae), Zootaxa 3801 (1), pp. 1-143 : 98

Syrphoctonus tarsatorius ( Panzer 1809, Bassus)

Bassus exsultans Gravenhorst 1829

Bassus insignis Gravenhorst 1829

Bassus flavus Desvignes 1862

Bassus indicus Cameron 1909

Homotropus eximius Habermehl 1922 (syn. nov.)

Homotropus flavitrochanterus Uchida 1957

Diagnosis. Fore wing length 3.9–6.4 mm. Antenna in females with 19–21 flagellomeres, in males with 19–23 flagellomeres, with tyloids on flagellomeres 6–7 to 14–16. Epicnemial carina sometimes only weakly interrupted behind fore coxa. Mesoscutum strongly coriaceous and distinctly punctate. Propodeum almost devoid of carinae, at most with pleural carina and apex of lateral longitudinal carina weakly indicated, sculpture coriaceous and matt. Female metasoma gradually tapered to apex, first tergite 1.0–1.4 times longer than wide in females, 1.2–1.5 in males; spiracle of third tergite slightly to distinctly below lateral fold.

Colouration of females. Antenna dark brown or black. Head and mesosoma black, face with a yellow central face patch, yellow on clypeus, mouthparts, hind corner of pronotum, tegula, sometimes subtegular ridge, large shoulder mark, upper mesepimeron, and most of scutellum. Legs orange, fore coxa dark, mid and hind coxae orange; femora orange; hind tibia dark orange with a dark apex, tarsus dark. Metasoma black, usually with hind margins of tergites 2 or 3 to 5 or 6 yellow.

Colouration of males. As in females but with yellow ventrally on antenna, entire face, entire propleuron, most of pronotum, epicnemium, a varying portion of mesosternum, and a stripe on lower mesopleuron. Fore and mid and often also hind coxae entirely yellow. Metasoma as in females but often with yellow posterior margins broader and yellow spots on basolateral corners of tergite 3.

Material examined. Holotype of Bassus indicus Cameron : India, Simla . 1♂, at BMNH . Holotype ♀ of Homotropus eximius Habermehl examined by Erich Diller (personal communication).

Finland (3), France (2), Germany (1), Hungary (30), Sweden (40), Switzerland (>100), Turkey (1), United Kingdom (30).

Distribution. Holarctic and Oriental.

Figures. Mesoscutum ( Fig. 12 B), epicnemical carina ( Fig. 16 B), clypeus ( Fig. 16 D), metasoma ♀ ( Fig. 24 B), habitus ( Fig. 34 F).

Notes. This is a species with a large range of variation in size and also colouration. Two specimens of a colour variant which might or might not represent a distinct species were found in the Swiss Alps and in Finland. They have a mostly black hind tibia with a whitish base and yellow posterior bands on tergites 2 to 7 instead of the usual 2 to 5 in females. No distinction from specimens with the typical orange hind tibia was found in the CO1, ND1 and 28S markers. It remains to be shown if this variant represents a distinct species.

Figures

FIGURE 24. Metasomas of Syrphoctonus species viewed from above. A. Syrphoctonus idari. B. Syrphoctonus tarsatorius. Scale bars represent 500 µm.

FIGURE 34. Habitus of Diplazontinae species. A. Sussaba montana. B. Sussaba pulchella. C. Sussaba roberti sp. nov. D. Syrphoctonus desvignesii. E. Syrphoctonus fissorius. F. Syrphoctonus tarsatorius.

FIGURE 12. A. Diplazon laetatorius ♀, mesonotum showing notauli. B. Syrphoctonus tarsatorius ♀, mesonotum. C. Diplazon tetragonus ♀, fore wing. D. Enizemum ornatum ♀, fore wing. E. Promethes sulcator ♀, head. F. Tymmophorus obscuripes ♀, head. G. Diplazon tetragonus ♀, clypeus. H. Tymmophorus suspiciosus ♀, clypeus. I. Daschia brevitarsis ♀, clypeus. J. Campocraspedon caudatus ♀, clypeus. K. Xestopelta gracillima ♀, clypeus. L. Diplazon tetragonus ♀, hind tibia.

FIGURE 16. A. Homotropus signatus ♀, epicnemical carina. B. Syrphoctonus tarsatorius ♀, epicnemical carina. C. Homotropus elegans ♀, clypeus. D. Syrphoctonus tarsatorius ♀, clypeus. E. Enizemum ornatum ♀, clypeus.