• Arthur, A.P.
  Div of Entomology, Dept of Agriculture, Ottawa, Canada
  
• Coppel, H.C.
  Laboratory of Entomology, Belleville, Ontario
  

Sarcophagia aldrichi Park. is a native parasite which has been reared continually, though small in numbers, from Choristoneura fumiferana (Clem.) in British Columbia. It is also an important parasite of Malacosoma disstria Hbn. and is apparently widely distributed throughout North America. The parasite can be reared in the laboratory on pork liver, or on a mixture of liver and fish, from larvae deposited on the rearing medium by ovoviviparous females. The total time required for development from deposition of the larvae to the beginning of the pupal formation was five to eight days. The puparia were formed 7 to 44 days later. No adults emerged without a period of diapause, which normally lasted throughout the winter months. The distinguishable characters of the immature stages are described. The methods used in rearing spruce budworm pupae for obtaining parasites are outlined.