LIFE HISTOEY OF CODLING MOTH IN PECOS VALLEY^ N. MEX. 79 



FOURTH BROOD OF LARV^. 



Length of feeding. — ^The first observation of larvae leaving the fruit was 

 made September 23, after a feeding period of 28 days. Records in this 

 comiection were kept with 125 individual insects and the last larvae were 

 found leaving the fruit on October 31, thus covering a period of 28 

 days. All of these individuals passed the winter as wmtering larvae. 



The maximum length of the feeding period for larvae of this gen- 

 eration was found to be 53 days, and the minimum period 25 days, 

 covering a range of variation of 28 days. The average feeding period 

 for the enthe time was 38.36 days, as shown in Table LVII. This 

 average feeding period is 17.26 days greater than the corresponding 

 average for wintering larvae of the third generation of this season, 

 and 11.81 days greater than the correspondmg average for all larvae 

 of the third generation during 1912. 



MISCELLANEOUS EMERGENCE OF MOTHS. 



Records of Tiourly observations. — In an endeavor to determine the 

 tune of day at which the greatest number of insects leave the pupal 

 case and emerge as moths, experiments were conducted by using a 

 number of glass jars in which larvae collected from banded trees had 

 been placed and on which daily emergence records were taken. 

 The first observations of the season were made April 28, usmg moths 

 of the spring brood. Observations were begun at 7 a. m. and con- 

 tinued throughout the day at intervals of one hour until 7 p. m. 

 Largely because of the cool weather prevailing at that early stage 

 of the season no emergences were fomid to take place until 11a. m., 

 when 1 moth was discovered. At 12 noon, however, 35 moths were 

 found and at this hour a thermograph withm the breedmg shelter 

 indicated a temperature of 84° Fahrenheit. At 1 p. m. a total of 14 

 moths was found and a temperature of 85° F. was recorded and later 

 noted as being the highest temperature throughout the day. 



On June 24 and 25 similar experiments were agam conducted 

 although no observations were made until 9 a. m., when the greatest 

 immber of accumulated moths was found for any particular hour, 

 being 55 in all. Records show an average temperature of 70° F., 

 for that hour on the two days. However, the highest emergence 

 during the more heated portion of the day occurred at 3 j). m. with 

 a total of 33 moths and an average temperature of 90° F., for that 

 hour on tlie two days. 



On August 1 siniihir records were made with enierghig moths of tlie 

 s(>con(l generation, and the first observation of tlie day was made at 7 

 a. m., when a total of 1 9 motlis was found. Tlie maximum emergence 

 of the day, however, occurred at 3 p. ni., when 103 individuals wercMlis- 

 covered. The tenif)erature njcords at this hour read 83° F., wliih^ the 

 maximum temperature of tlio day occurred at 12 noon and was found 

 to})e89° F. Kni(Tg(!nr('H forofluM- Jioura throughout the day on wliicli 

 r(!Cords wcue tak(;n wci-e found 1o he. in varying iiundx'rs, as is shown 

 in Table L\T 1 1 . Of ii. tuhd of T.'>\ lecords of indivi(hial cnKirgcnces, 

 55888^— Bull. 42'J— 17 «i 



