February, '17] BECKER: PEACH-TREE BORER 49 



NOTES ON THE PEACH-TREE BORER (SANNINOIDEA 



EXITIOSA) 



By Geo. G. Becker, Fayetteville, Ark. 



Before taking up the subject of this paper the writer wishes to make 

 acknowledgments to Messrs. W. C. Quick, W. D. Merrill and William 

 Lee, who, as student assistants under his direction, made a great many 

 of the observations recorded in this paper. 



Most of the notes are made on pupation, and on the emergence and 

 habits of the moths. 



Pupation 



Attempts were made to ascertain the time required in spinning up, 

 the time spent as larva in the cocoon and the time spent in the cocoon 

 in the actual pupal stage. The problem was fraught with some diffi- 

 culties and the data here offered are at best more or less fragmentary. 



As long as four days may be required to construct a cocoon, though it 

 appears that with average larvse this does not require more than a day. 



After spinning up in its cocoon the larva remains in this stage for a 

 period of 5 to 9 days. During this time it doubtless works for a day 

 or so finishing up the interior of its cocoon and then rests awhile before 

 transforming to the pupal stage. We had one larva spin its cocoon 

 and transform to the pupal stage in six days. 



The duration of the pupal stage within the cocoon appears to be 

 about three weeks, though here again there seems to be a variation 

 with individuals. One individual which was observed as a tender 

 white recently transformed pupa emerged 13 days later as an adult, 

 thus requiring only 13 days for its pupal stage. Our observations 

 lead us to the conclusion that the time which elapses from the time 

 that the larva spins its cocoon to the time that the moth emerges 

 ranges from 18 to 30 days. 



Emergence 



Emergence from the pupal stage was watched with considerable 

 interest and from the observations of 1916, which need to be verified, 

 it appeared that there were four stages of emergence. 



Emergence occurred from 6 to 10 a. m., but was apparently most 

 active from 8.30 to 9 on bright clear days. Doubtless this would 

 vary with the time of the year when emergence took place, being earlier 

 on long days than on the shorter and cooler days later in the season. 



Atmospheric and light conditions seemed to be the factors govern- 

 ing emergence after the pupae were mature for the transformation, 

 though light seemed to be the more important. 



