Following initial establishment of the parasitoid, Tetrastichus julis (Walker), at a carefully managed field nursery, releases of parasitized Oulema melanopus larvae were made by Michigan county agents at preselected sites throughout the lower peninsula during 1970-74. A follow-up recovery program during 1971-75 revealed continued dispersion and population increase for T. julis. An independent census verified the increasing rates of parasitism.
Logan, P. A.; Stehr, F. W.; and Sauer, R. J.
"The Subcolonization and Buildup of Tetrastichus Julis, (Hymenoptera: Eulophidae) a Larval Parasitoid of the Cereal Leaf Beetle, (Coleoptera: Chrysomelidae) in the Lower Peninsula of Michigan,"
The Great Lakes Entomologist, vol 9
Available at: https://scholar.valpo.edu/tgle/vol9/iss1/5