Hyposoter clausus ( Brischke, 1880 )

Galsworthy, Anthony, Shaw, Mark R. & Haraldseide, Håkon, 2023, A key to European species of Hyposoter Förster, 1869 (Ichneumonidae: Campopleginae) with descriptions of 18 new species, and notes on all included species, Zootaxa 5290 (1), pp. 1-73 : 38-39

Hyposoter clausus ( Brischke, 1880)

Limneria clausa Brischke, 1880 : type ♀, lost.

The type material of this species is lost, as is much of Brischke’s collection. The name was applied, apparently consistently, thereafter by such authorities as Bridgman (1881 and 1885) and Schmeideknecht (1909) to a species which fits Brischke’s original description well, and has continued to be so applied more recently (eg Aubert. 1973; Shaw et al. 2016). The species is not covered in Horstmann’s notes, though he referred to it in several faunistic publications and included it in his draft key, and there is a good series named by him in his collection. The species is reasonably well known, and there seems no reason to question the application of the name to it.

Identification is straightforward when the underside of the head is visible: the genal carina peters out well before junction with the hypostomal carina, and is replaced by a bulge covered with grey hairs. But when this is invisible, confusion with H. placidus is possible. Both species lack emargination of the seventh tergite. The best distinction between the two lies in the sculpture of the mesopleuron: in clausus , the granulate sculpture on the lower mesopleuron is fine and in low relief with small punctures separated by more than their diameters; in placidus it is in higher relief, often almost cellular, with larger, closer and more easily visible punctures. On the upper mesopleuron forward of the speculum, placidus invariably has patches of striation and high rugosity which are lacking in clausus . Hyposoter placidus also lacks yellow on the underside of the scape in both sexes. The ovipositor in clausus is very short, with the sheaths only about half the apical height of the metasoma.

Hyposoter clausus has been reared from a variety of geometrid moth larvae, and from one noctuid, Polia tricoma (Hufnagel) (details in Shaw et al. 2016). In the NHMUK collection there is a long series of specimens reared by G.T.Lyle in the first half of the 20th century: these are unfortunately glued face down onto cards, which prevents determination with absolute certainty, but they are very probably this species. All were reared from Geometridae , 12 from Agriopis marginaria (Fabricius) , seven from Peribatodes rhomboidaria (Denis & Schifferm̧ller), and one from L. pusaria , probably Cabera pusaria (Linnaeus) . We have seen specimens from the UK, Germany, Norway, and Poland. It has been reported in addition from Finland, the Czech Republic, France and Romania in Europe, and also from Iran and Pakistan.

Three specimens from the third author’s collection were barcoded (BOLD Sample IDs CollHH1219, 1221, and 3476).