Other Common Names
lady beetle parasitoid wasp
Synonyms and other taxonomic changes
Perilitus coccinellae (Schrank) 1802
Range
It has worldwide distribution. Probably an introduced species.
Naturespot. UKRemarks
"It attacks ladybird beetle adults (and sometime late instar lavae). It lays its egg within the adult beetle, the egg develops into the first instar larvae where it waits within the beetle as they overwinter. About a month after it warms up, the wasp will emerge from the beetle as a larva, and spin a cocoon underneath the beetle's dead body. The aposomatic colors supposedly (very likely) protect the wasp larvae as it pupates." --Andy Boring
Probably an introduced species.
See Maria's comment on

Internet References
Dinocampus coccinellae. Parasitoid wasp threatens Scottish Seven Spot ladybird.