• Coppel, H.C.
  Div of Entomology, Dept of Agriculture, Ottawa, Canada
  
• Maw, M.G.
  Dept of Entomology, Belleville, Ontario
  

Studies initiated in British Columbia in 1943 showed that Madremyia saundersii (Will), a native parasite with a wide range of lepidopterous hosts in North America, was a parasite of the spruce budworm, Chorsitoneura fumiferana (Clem.). The parasite has been obtained each year since then in moderate numbers and released in infested areas of Eastern Canada. M. saundersii deposits macroptype eggs on the integument of host larvae. The first stage larvae penetrate the integument of the host. The larvae attach themselves to tracheal trunks, where they remain throughout the first and second stages, but during the third feeding stage they wander freely within the body, devouring all the contents. The period from egg deposition to adult emergence was 17 to 23 days under laboratory conditions. The life history and habits of the insect are outlined, and are supplemented by general field observations. The immature stages of the parasite are illustrated and described.