Parasitoids (Hymenoptera: Braconidae: Aphidiinae) of Aphids Feeding on Ornamental Trees in Southeastern Europe: Key for Identification and Tritrophic Associations

Ornamental trees are valuable natural elements which provide several economic, aesthetic, and ecological benefits to humans. They are seriously infested by numerous pests and diseases, among which aphids are of high importance. Here we present a comprehensive list of Aphidiinae parasitoid species that attack aphids on ornamental trees in southeastern Europe, some of which are potential biocontrol agents. Thirty-eight species of Aphidiinae are recorded, keyed, and illustrated. Fifty-six out of 120 recorded tritrophic (parasitoid – aphid – plant) associations were previously unknown. The results are discussed in relation to the overall parasitoid – aphid – tree associations in the target region, as well as potential of parasitoid use in biological control programs.