A key to European species of Hyposoter Förster, 1869 (Ichneumonidae: Campopleginae) with descriptions of 18 new species, and notes on all included species Author Galsworthy, Anthony 0009-0009-6612-9847 acgalsworthy@btopenworld.com Author Shaw, Mark R. 0000-0002-6651-8801 markshaw1945@gmail.com Author Haraldseide, Håkon 0009-0009-6612-9847 acgalsworthy@btopenworld.com text Zootaxa 2023 2023-05-18 5290 1 1 73 http://dx.doi.org/10.11646/zootaxa.5290.1.1 journal article 53361 10.11646/zootaxa.5290.1.1 36037514-64e6-4cde-88f9-583b4b9d8bf1 1175-5326 7959256 FD54D381-F123-4958-A03E-6CA71E02D06A Hyposoter dubitatus ( Holmgren, 1860 ) stat. rev. Limneria dubitata Holmgren, 1860 : lectotype ♀ in NHRS, designated by Hinz (1962), examined. Limneria dubitata Holmgren was synonymized with Campoplex sicarius Gravenhorst, 1829 by Schmiedeknecht (1909) , though without explanation. Aubert (1972) , after examining the lectotype , stated that the synonymy with sicarius was ‘doubtful’. Horstmann’s draft key makes it clear that he had intended to separate dubitatus from sicarius , but we have not found evidence in his notes that he had seen the lectotype of dubitatus . However, we have seen the lectotype , and confirm that it is quite different from the specimen of sicarius in Horstmann’s collection which he had compared with the type of the latter. We therefore formalise here Horstmann’s intention to restore dubitatus to valid species status stat. rev. Three specimens ( one male and two females ) in Horstmann’s collection from northern Germany had originally been identified by Horstmann as H. thuringiacus Schmiedeknecht , but bear Horstmann’s labels correcting this to H. dubitatus . They match the type of dubitatus very well (see above under H. thuringiacus in the section on species excluded from the key). The species is very similar to H. caedator : see notes under that species for separation of the two. The type material is from Sweden . The two female specimens in Horstmann’s collection mentioned above bear labels ‘ex Epione parallelaria’, i.e. Epione vespertaria (Linnaeus) ( Lepidoptera , Geometridae ), though there are no cocoons or larval remains. One specimen in NMS was reared in Italy from an unknown geometrid and a further specimen in the French Alps also from an indeterminate geometrid, possibly Eulithis . There are also further specimens in NMS from France and from the UK .