EN
Adult ichneumonids of Hyposoter placidus were reared from caterpillars of the large copper butterfly Lycaena dispar collected in NE Poland, feeding on Rumex confertus, R. hydrolapathum and R. obtusifolius. This is the first record of this parasitoid in the country. We hypothesize that H. placidus may be a factor limiting the abundance of populations of L. dispar, a widespread species but usually occurring in low numbers.