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PROCEEDINGS ENTOMOLOGICAL SOCIETY 



Some time subsequent to the preparation of this manuscript it 

 was my privilege to see Dr. J. C. Nielson's most interesting paper 1 

 relative to his experiments with Tachina larvarum Linn, (a species 

 very closely related to, if not identical with, our Tachina mella 

 Walk.) and its parasitism on Zygaena filipendulae in Denmark. 

 My experiments while conducted on a much smaller scale seem to 

 indicate results which are in the main parallel with his. That is to 

 say, the deposition of supernumerary eggs resulted in a diminution 

 of size in the resulting parasites. However, he says, "in cases where 

 several flies emerged from the same host ; their size was not equally 

 reduced, one or two of them not differing in size from that of flies 

 which had developed solitary, the remainder being undersized." 

 He does not, however, state whether the solitary specimens men- 

 tioned were those resulting from the deposition of one, or more than 

 one egg on the host caterpillar. 



The detailed results of my somewhat limited investigation are 

 summarized below in the appended table : 



In discussing this paper Mr. Pierce stated that in the South 

 he had found Chelonus texanus Cresson (det. Viereck) which laid 

 its egg in the egg of Laphygma to be a much more efficient parasite 



1 Undersogelser over entoparasitiske Muscide larver hos Arthropoder 

 af Dr. J. C. Nielson, Saertryk af Vidensk. Medd. fra den naturh. Foren. 

 Bd. 64 p. 215-248. 



