Braconidae 495 



collected and placed in an emergence cage, just before the adults emerge. 



(4) Peach twigs infested with fruit moth larvae and then exposed 

 to Macrocentrus for oviposition have also been used. When young fresh 

 twigs are not available, slits are made in older twigs, fruit moth larvae 

 inserted and frass placed on the outside to incite oviposition. Larvae 

 are removed from the cages as soon as parasitized, and reared to 

 maturity. 



The last two methods have been used successfully at the New York 

 Agricultural Station. 



Bibliography 



Allen, H. W. 1931. The mass production of Macrocentrus ancylivorus a parasite 



of the Oriental fruit moth and its distribution from southern New Jersey. J. Econ. 



Ent., 24:309. 

 Daniel, D. W. 1932. Macrocentrus ancylivorus Rohwer, a polyembryonic braconid 



parasite of the Oriental fruit moth. N. Y. State Agric. Exper. Sta. Tech. Bull. 187. 

 Garman, Philip, and Brigham, W. T. 1933. Studies on parasites of the Oriental 



fruit moth. II. Macrocentrus. Conn. Agric. Exper. Sta. Bull. 356. 



REARING APHIDIINAE 



Esther W. Wheeler, University of North Dakota 



DURING the winter and spring, roomy lamp chimneys were placed 

 over potted plants in a small greenhouse. Lawn cloth stretched 

 tightly over the top of the chimney and held in place by a rubber band 

 gave free circulation of air and prevented the insects from escaping. 

 The aphids were allowed to grow at least two weeks to exclude any 

 possibility of undetected previous parasitism. Then an aphidiine 

 female was introduced and allowed to oviposit. Various stages of the 

 Aphidiinae were obtained by dissecting aphids at intervals. Moisture 

 condensing on the glass caused trouble occasionally, but the chimney 

 might be removed and wiped out quickly without losing the insects. 

 In summer the greenhouse was too hot for them. 



Another method which was more satisfactory, and absolutely neces- 

 sary in the case of a plant too large for a lamp chimney, required petri 

 dishes. This procedure was carried out in a large, dry laboratory, 

 steam-heated in winter and cool in summer. The bottom of the dish 

 was lined with slightly moistened coarse filter paper, upon which were 

 placed clean leaves of the host plant. Finally unparasitized apterous 

 aphids and a female parasite were introduced. The leaves were changed 

 every day; the insects were transferred with a fine, dry camel's hair 

 brush; and every two days, or oftener if signs of condensation appeared, 

 the dish and paper were changed. In spite of the fact that the 

 Aphidiinae are agile they rarely escaped. In these few cases their 

 positive phototropism would lead them to the nearest window where 



