26 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table IX. — Feeding periods of second-brood larvae in pears, Walnut Creek, Cal.,1909. 





Date of— 







Date of — 







Date of — 





indi- 

 vid- 

 ual 

 No. 







Period 

 of feed- 



Indi- 

 vid- 

 ual 

 No. 







Period 

 of feed- j 



Indi- 

 vid- 

 ual 

 No. 







Period 















of feed- 



Hatch- 

 ing. 



Leaving 

 the fruit. 



ing. 



Hatch- 

 ing. 



Leaving 

 the fruit. 



ing. 



Hatch- 

 ing. 



Leaving 

 the fruit. 



ing. 









Days. 









Days. 









Days. 



1... 



Julv 12 



Aug. 18 



37 



22... 



July 25 



Aug. 26 



32 



43... 



Aug. 2 



Aug. 20 



18 



'2a.. 



12 



14 



33 



23a.. 



26 



20 



25 



44... 



2 



20 



18 



3... 



12 



19 



38 



24... 



26 



20 



25 



45... 



2 



22 



20 



4a.. 



16 



13 



28 



25... 



26 



23 



28 



46... 



2 



27 



25 



5a.. 



16 



21 



36 



26... 



26 



22 



27 



47... 



2 



29 



27 



6a.. 



16 



14 



29 



27... 



26 



20 



25 



48... 



2 



26 



24 



la.. 



16 



16 



31 



28... 



26 



21 



26 



49... 



2 



26 



24 



8a.. 



16 



21 



36 



29... 



28 



18 



21 



50... 



2 



29 



27 



9a.. 



24 



19 



26 



30... 



28 



21 



24 



51... 



3 



27 



24 



10... 



24 



20 



27 



31... 



29 



25 



27 



52... 



3 



21 



18 



11a. . 



24 



19 



26 



32... 



29 



21 



23 



53... 



3 



29 



26 



12... 



24 



21 



28 



33... 



29 



28 



30 



54... 



3 



31 



28 



13... 



24 



27 



34 



34... 



29 



22 



24 



55... 



3 



26 



23 



14... 



24 



21 



28 



35... 



29 



19 



21 



56... 



3 



27 



24 



15... 



24 



28 



35 



36... 



29 



23 



25 



57... 



4 



25 



21 



16... 



25 



18 



24 



37... 



29 



24 



26 



58... 



4 



28 



24 



17a.. 



25 



20 



26 



38... 



29 



Sept. 8 



41 



59... 



4 



31 



27 



18... 



25 



18 



24 



39... 



29 



Aug. 12 



14 



60... 



6 



Sept. 1 



26 



19... 



25 



26 



32 



40... 



29 



13 



1'5 1 



61... 



6 



Aug. 29 



23 



20... 



25 



21 



27 



41... 



Aug. 2 



26 



24 i 



62... 



6 



31 



25 



21... 



25 



27 



33 



42... 



2 



24 



22 



63... 



6 



31 



25 



a Pupated and moth emerged in September. 



Feeding period: 

 Average . . . 

 Maximum. 



Minimum. 



Davs. 

 . 26.34 

 . 41.00 

 . 14.00 



Overwintering larvx. — The first larvae not pupating but going into 

 winter cocoons in 1909 were taken from bands July 17. Of 78 larvae 

 taken on this date, 38 pupated and adults emerged, 28 died, and 20 

 went through the winter as larvae. Of 196 larvae and pupae collected 

 under bands on June 28, 1910, 5 did not pupate but wintered as larvae 

 in cocoons. After this date the percentage of overwintering larvae 

 increased. However, some adults emerged as late as September 18. 

 With the development of the second brood there was a marked 

 increase in the number of overwintering larvae. Of some 95 to 100 

 larvae developing in fruit out-of-doors at the laboratory, only 9 

 pupated. These were Xos. 2, 4, 6, 7, 8, 9, 11, 17, and 23 in Table IX. 

 Adults emerged 17 to 36 days after leaving fruit. This would give 

 some 6 to 7 weeks for the life of the individuals of the second genera- 

 tion. 



REVIEW OF LIFE HISTORY FOR THE YEARS 1909 AND 1910. 



There are practically two full broods of larvae each year in the inte- 

 rior counties of California. It is not easy to distinguish definitely 

 between the two o-enerations bv field observations alone, and to know 

 just when all the first-brood larvae are in the fruit, although there is 

 a period of some weeks each summer during which very few eggs are 

 laid. Taking into consideration the difference in time required for 

 development of eggs and larvae, and the fact that the pears are picked 

 before very many of the second-brood larvae leave the fruit, it is diffi- 

 cult to determine the division of generations by band records. Some 

 growers report that young larvae are hatching and entering fruit 



