December, '17] KELLY: BIOLOGY OF CCELINIDEA 529 



The Meromyza eggs into which these parasites oviposited were col- 

 lected and placed in a large vial, where they were kept with especial 

 care until the following spring, but no parasites issued from the eggs, 

 and upon careful examination they were found to be mere shells. 



At the time the oviposition was first observed, the relative size of the 

 parasite and the egg was carefully considered, and the writer wondered 

 how such a large parasite could mature in so small an egg, it being 

 fully four times as large. However, the following spring, the writer 

 observed Diplazon latatorius Forb. ovipositing in a similar manner into 

 the eggs of a Syrphid, which had been placed among a number of 

 aphids, on the stems and leaves of a chrysanthemum. The Syrphid 

 eggs were collected for observation. They soon hatched into tiny 

 Syrphid larvae, which were supplied with aphids for food; they matured 

 as larvae, and pupated, but instead of a Syrphid adult from the Syrphid 

 pupa there issued an adult of Diplazon loetatorius (Jour. Econ. Ent., 

 V. 7). The writer was then convinced that his observations the preced- 

 ing fall on Ccelinidea meromyzcewere correct, but that improper methods 

 had been used in an effort to rear the parasite. The Meromyza eggs 

 should have been permitted to hatch and mature on the wheat 

 plant. 



Since the first observation in 1908, this parasite was not again ob- 

 served until the fall of 1914, although diligent search had been made 

 for it in the fields, and a large number of Meromyza larvae had been 

 collected and reared to maturity in an attempt to rear the parasite. 



During the summer and fall of 1914 a large number of wheat plants 

 were secured from different localities in Iowa, Missouri, IlHnois, 

 Arkansas, South Dakota, Oklahoma, Kansas, and Nebraska. Many of 

 these wheat plants were infested with Meromijza americana Fitch. 

 Upon receipt of this material at the laboratory it was placed in breeding 

 cages, each consisting of a large tin can with a small hole punched in one 

 side near the top into which a glass vial was inserted for the purpose of 

 obtaining the mature Meromyza and parasites as they issued. The 

 infested wheat plants which were placed in the warm room of the 

 laboratory produced adults of Meromyza americana late in the winter, 

 and soon after these began to issue the parasite Ccelinidea meromyzce 

 began to issue from the same material. Upon comparing these parasites 

 with those collected in September, 1908, they were found to be iden- 

 tical. 



Now that the writer was convinced that he had observed this parasite 

 ovipositing into the eggs of Mero^nyza americana in the fall of 1908, he at 

 once set about to rear the parasite in the laboratory. Fortunately a 

 number of Meromyza adults were issuing in early February, in the 

 laboratory, and they were at once placed on potted wheat plants, under 



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