ECDYSIS IN TMETOCERA OCELLANA SCHIFF. 



S. W. Frost, 

 State College, Pa. 



An examination of the literature on the Bud-moth, 

 {Tmetocera ocellana Schiff.) reveals little concerning the moult- 

 ing of such a common pest. In fact there has been very little 

 investigation of the moulting of any of the Lepidoptera and 

 especially of the measurement of the moulted head capsules. 

 In response to the need of detailed study on this phase of the 

 life history, the writer has assembled the following notes. 



A brief summary of the development of the subject may be 

 of value. Several writers have previously called attention 

 to the moulting habit of the Bud-moth, but there still remains 

 an opportunity for considerable investigation along this line. 

 Mr. H. G. Dyar, of the United States National Museum, 

 several years ago made a valuable contribution in the form 

 of a series of head measurements of the first five instars of the 

 Bud-moth larvae. His notes were published by Prof. M. V. 

 Slingerland (1893).* Further information has been supplied 

 by Prof. Slingerland in the same bulletin. Mr. G. E. Sanders 

 and A. F. Dustan (1919)t in their work on the Bud-moths of 

 Canada, have added likewise to our knowledge of the ecdysis 

 of T. ocellana Schiff. The numerous other papers, chiefly of 

 economic importance, add very little to the study. 



METHOD OF STUDY. 



This study has been divided into four parts. (1) The 

 moulting process, (2) The number of moults, (3) The measure- 

 ment of the moulted head capsules, (4) The shape and structure 

 of the head capsules. 



The larvae used in obtaining these records were hatched 

 from eggs laid in confinement and were examined and fed at 

 least once a day. Each larva was placed in a separate four 

 dram vial with a small portion of the leaf as food. As soon 

 as the moults occurred, the head capsules were removed and 

 placed in individual jelletin capsules and properly labelled by 

 means of colored papers according to the number of the moult. 

 All measurements were made at the end of the season. 



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