Spalangia endius were collected from fly pupae, primarily house fly and stable fly, from a poultry house in Indiana. Male and female wasps did not differ within and across host species in host size usage. Also, despite stable fly pupae being significantly smaller than house fly pupae, the proportion of male wasps emerging from the two host species was similar.
King, B. H.
"No Intersexual Differences in Host Size and Species Usage in Spalangia Endius (Hymenoptera: Pteromalidae),"
The Great Lakes Entomologist, vol 24
Available at: https://scholar.valpo.edu/tgle/vol24/iss1/3