46 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



FIRST-BROOD OP LARV.E. 



Time of hatching. — Tho earliest newly hatched larvae appeared in 

 the field about June 7, eggs being deposited on May 28 and the first 

 larva from the band records being collected June 27. The greatest 

 number of larvae hatched between June 17 and July 7. A few isolated 

 larvae hatched as late as July 20. 



Length of feeding period of transforming larvse. — The feeding period 

 for the transforming larvae of the first brood was determined from 70 

 individuals, as given in Table LV. The average length of feeding 

 was 21.25 days, the maximum 29 days, and the minimum 15 days. 

 These results show a shortening of the feeding period as compared 

 with the records for 1910, which must have been due to the excep- 

 tionally warm season of 1911. 



Table XLVII. 



-Length of feeding period of wintering larvse of the Jirsb brood, Douglas, 

 Mich., 1911. 



Length of feeding period of wintering larvse. — On comparing records 

 of the feeding period of the wintering larvae with those of the trans- 

 forming larvae it will be noted that there is a marked difference, in that 

 the wintering larvae fed for a much longer period of time. The aver- 

 age for the wintering larvae is 28.2 days, the maximum 41 days, and 

 the minimum 18 days (see Table XLVII) and for the transforming 

 larvae the average is 21.25 days, the maximum 29 days, and the 

 minimum 15 days (Table LV). This difference of habit of the two 

 sets of larvae was also observed during 1910 and has been referred to 

 in connection with the studies for that year. 



About one-half of the first-brood larvae recorded in Table LV were 

 reared in bagged fruit on the trees, and the other half in fruit in cages. 



