Insects are the most numerous and species rich group of animals on Earth. One of the four mega diverse orders within the class Insecta is Hymenoptera which include ants, bees and parasitic wasps. One of the many Hymenopteran subfamilies is Adeliinae, a group of tiny wasps that parasitize leaf mining Lepidoptera larvae. Only one described species of Adeliinae is hitherto known to occur in Sweden. However, this known species exhibits a wide range of polymorphism. In fact, the hypotheses if Adeliinae constitute a subfamily with just a few, but very variable species or if it is composed by a rich number of very similar species have never been tested before. The results in this study confirm the variation, but cannot state which of the hypotheses that is the most correct. Furthermore, the processed information from the traps in which the wasps were caught show that the Adeliinae are spread throughout Sweden and appear in a wide variety of habitats.