20 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table VI. — Life cycle of the first generation, Walnut Creek, Col., 1909 — Continued. 





Date of — 



Days for— 



Individ- 

 ual No. 



Egg dep- 

 osition 

 (night). 



Hatch- 

 ing. 



Larva 



leaving 



fruit. 



Pupa- 

 tion. 



Emer- 

 gence of 

 moths. 



Incu- 

 bation. 



Feed- 

 ing of 

 larva. 



Making 

 of co- 

 coon. 



Pupal 

 period. 



Total 



life 



cycle. 



37 



May 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 



10 

 10 

 10 



May 30 

 30 

 30 



July 1 



2 



29 



July 6 

 6 



July 25 

 25 



21 

 21 

 21 



32 

 33 

 30 



5 

 4 



19 

 19 



77 



38 



77 



39 





40 













41 



30 

 30 

 30 

 29 

 29 

 30 

 30 

 30 

 30 

 30 

 30 

 30 

 30 

 29 

 29 

 27 









21 



21 

 21 

 20 

 20 

 21 

 21 

 21 

 21 

 21 

 21 

 21 

 21 

 19 

 19 

 17 











42 



25 







26 









43 













44.. 



27 

 24 

 28 





19 



29 

 26 

 29 









45.. 











46 













47 













48/ 



49 . 



1 







32 



















50l . . 



11 







42 









51 













52 

















53 



54. 



June 28 



6 



22 



29 



8 



16 



74 



55 



30 



30 







32 



34 









56 



6 



20 



6 



14 



71 







SUMMARY. 





Days for — 



Observations. 



Incuba- 

 tion. 



Feeding 



of 

 larva. 



Making 



of 

 cocoon. 



Pupal 

 period. 



Total life 

 cycle. 



Average 



20. 05 

 22.00 

 17.00 



29.97 

 42.00 

 24.00 



6.85 



11.00 



4.00 



17.58 

 23.00 

 14.00 



74.25 



Maximum 



78.00 



Minimum 



71.00 







FIRST-BROOD LARVAE. 



Time of hatching. — The first larvae under observation in 1909 

 hatched May 7 from eggs brought in from the field. On May 11, 8 

 recently hatched larvae were found in the orchard. On this same 

 date, May 11, 1910, young larvae were quite numerous in the field. 

 At Suisun, CaL, in 1910, the first larva was found April 29, and 

 recently hatched larvae were quite numerous by May 3. Very 

 young larvae were found continuously until the 1st of June. Larvae 

 at laboratory hatched May 26 to 30, and it is very likely that all 

 first-brood eggs in the field had hatched and all larvae were in fruit 

 by this time. 



Development of larvx in fruit. — Of the larvae hatching under 

 observation in 1909, only 29 reached full development in the fruit, 

 requiring from 25 to 42 days. The individual records are given in 

 Table VI. The first larva to leave the fruit in the field was not 

 observed, but on June 5 three newly formed pupae and 20 full-grown 

 larvae were found under bands on 21 pear trees, and 4 pupae and 28 



