Hyposoter horticola ( Gravenhorst, 1829 )

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 : 48

Hyposoter horticola ( Gravenhorst, 1829)

Campoplex horticola Gravenhorst, 1829 : lectotype ♁ in UWCP, designated by Horstmann (2000) and examined by him.

The female is easily distinguished from all other Hyposoter by the unique structure of the eighth tergite, whereby the lateral edges are extended backwards to form a covering for the ovipositor and its sheaths. The male has a deeply incised seventh tergite.

The species is a parasitoid of various species of melitaeine Nymphalidae (Lepidoptera) : Melitaea athalia (Rottemburg) , M. cinxia (Linnaeus) , and Mellicta aurelia (Nickerl) ( Shaw et al. 2016) . There is a detailed account of its life history in Finland by Nouhuys & Ehrnsten (2004) and Nouhuys & Kaartinen (2008) as a parasitoid of M. cinxia , which is parasitized just before it leaves its egg by females that have located and monitored the egg batch over time. Oviposition through the host’s eggshell may account for the unusual structure of the female’s 8th tergite.

We have seen specimens from Finland, Poland, Germany, France and Spain. The species has also been reported from Sweden, Hungary and Romania. Two specimens from the third author’s collection were barcoded (BOLD Sample IDs CollHH3481 and 3482).