Bradley, G.A. 1973 Effect of Formica obscuripes (Hymenoptera: Formicidae) on the predator-prey relationship between Hyperaspis congressis (Coleoptera: Coccinellidae) and Toumeyella numismaticum (Homoptera: Coccidae).. Canadian Entomologist 105: 1113-1118.

Notes: Toumeyella numismaticum occurred in small areas of heavy infestation in jack pine, Pinus banksiana, stands of southeastern Manitoba, where it was present in the same areas every year. The large populations of Formica obscuripes present in the scale-infestated areas lessened the effectiveness of the main predator of the scale, the coccinellid Hyperaspis congressis, through interference with the Hyperaspis adults.