THE GEAPE PHYLLOXERA I1ST CALIFORNIA. 



93 



In 1915, in all, there were reared to maturity 52 sexuals, of which 

 9 were males, 2 of these having hatched from eggs of intermediate 

 dimensions. These 2 males were noticeably larger than the other 7. 

 The majority of the sexuals were reared in darkness under cellar 

 conditions, the temperatures never averaging over 70.5° F. and in 

 one instance falling to 61.5° F. A noticeable phenomenon was the 

 death of a great number of sexes during the fourth instar, which 

 appeared to be due to their inability to cast the final skin as a result 

 of a deficiency of moisture. Tables XXXII and XXXIII show 

 the development of the sexes in 1915. 



Table XXXII. — Development of sexed forms of the grape phylloxera, Walnut 



Creek, Calif., 1915. 



Individual No. 



Date of 

 egg de- 

 position. 



Date of 

 maturing 

 of sexual. 



Develop- 

 mental 

 period. 



Sex. 



Average 

 tempera- 

 ture. 



Environment. 



1... 



July 17 

 ...do 



July 28 

 ...do 



July 30 

 ...do 



Days. 

 11 

 11 

 11 

 13 

 13 

 10 

 11 

 12 

 12 

 9 

 10 

 10 

 11 

 11 

 11 

 11 

 12 

 13 

 9 

 10 

 10 

 10 

 11 

 11 

 11 

 11 

 11 

 11 

 11 

 11 

 11 

 11 

 12 

 12 

 13 

 14 

 15 

 14 

 12 

 15 

 15 

 16 

 16 

 17 

 15 

 15 

 16 

 17 

 18 

 19 

 19 

 21 



9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 3 

 9 

 9 

 3 

 9 

 3 

 9 

 9 

 9 

 9 

 9 

 9 

 9 

 3 

 9 

 9 

 3 

 3 

 3 

 9 

 9 

 9 

 9 

 9 

 9 

 3 

 9 

 3 

 9 

 9 

 9 

 9 

 9 



°F. 

 70.3 

 70.3 

 70.3 



70 

 70 





2. 





4. 



...do 



[cellar. 



5. 



...do 





6. 



July 18 

 July 22 

 ...do 



July 28 

 Aug. 2 

 Aug. 3 



...do 



Aug. 8 

 Aug. 10 



...do 



Aug. 12 



...do....- 



...do..... 



...do 



Aug. 13 

 Aug. 14 

 Aug. 12 

 Aug. 13 



...do 



...do 



Aug. 14 

 Aug. 15 

 Aug. 16 



...do 



...do 



...do 



...do 



...do 



...do 



Aug. 17 

 Aug. 18 



...do 



Aug. 19 

 Sept. 8 

 Sept. 9 

 Sept. 15 

 Oct. 4 

 Oct. 9 



...do 



Oct. 10 

 Oct. 12 

 Oct. 13 

 Oct. 21 



...do 



Oct. 22 

 Oct. 24 

 Oct. 25 

 Nov. 1 



Nov. 3 





7. 



70 

 70 

 70 



1 



8. 



ICellar. 



9. 



...do 



I 



10 



July 30 

 July 31 

 ...do 





11 



69.8 

 69.8 

 69.7 

 69.7 





12 





13 



Aug. 1 

 ...do 



[Cellar. 



14. 





15. 



...do 





16. 



...do 







17. 



...do 







18. 



...do 







19. . 



Aug. 3 

 ...do 







20. 







21. 



...do 







22. 



...do 







23. 



...do 







24. 



Aug. 4 

 Aug. 5 

 ...do 



69 



68.8 



68.8 



68.8 



68.8 



68.8 



68.8 



68.8 



68.5 



68.5 



68.5 



68.6 



68.7 



68.7 



66.9 



64.9 



64.9 



64.9 



64.8 



64.3 



64.3 





25 





26. 





27. 



...do 





28. 



...do 





29. 



...do 





30. 



...do.... 





31. 



...do.... 





32. 



Aug. 6 

 ...do 





33- 





34. 



...do 



[cellar. 



35. 



. .do.... 





36. . 



Aug. 25 

 ...do 





37. 





38 



Sept. 1 

 Sept. 22 

 Sept. 24 

 ...do 





39 





40 





41 . 





42. . 



...do 





43. 



Sept. 26 

 ...do 





44. 





45. 



Oct. - 6 

 .do 





46. 





j-Room of laboratory. 



47. 



.do 







48. .. 



Oct. 7 

 ...do 



62 



62 



61.5 



61.5 



61.7 





49. 





50.... 



Oct. 13 



...do 



. .do 



[cellar. 



51 



52 











