Flies can be controlled cheaply and effectively by DDT properly used. Farmers in Iowa and other states have given it an experimental trial on livestock, in their barns, in other outbuildings and have okayed it as an efficient fly-fighting weapon.
"Farmers Try DDT For Flies!,"
Farm Science Reporter: Vol. 7
, Article 3.
Available at: https://lib.dr.iastate.edu/farmsciencereporter/vol7/iss1/3