New York Agricultural Experiment Station. 



303 



Table III.— Length of Period of Gkotnth of San Jose Scale Larv-S. 

 Date began to reproduce. j'^": Kemarka. 



Larva Date settled 

 No. down. 



No. 

 days. 



1 

 2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 

 17 

 18 



19 



Sept. 



<< 

 (( 

 II 

 (< 

 << 

 (( 

 <i 

 <( 

 (( 

 (( 

 <i 



(4 



6 

 6 

 6 

 6 

 6 

 6 

 6 

 6 

 6 

 6 

 6 

 6 

 6 

 7 

 6 



Aug. 29 



Oct. 24. 



" 27. 



None to Dee. 31. 

 (I (( 



<( « 



<< « 



Oct. 28. 



None to Dec. 31. 

 <( (( 



Oct. 25. 

 None to Dec. 31. 



Oct. 29. 

 On Nov. 11 bnd 25 larv89 

 None to Dec. 31. 



Oct. 7 had together 101 



48 

 51 



On apples in laboratory. 



laiv£8. 



f 1 



29 



Oct. 12. 



Average 



49.5 days. 



The table shows that but ten or a little more than half of these 

 females produced larvae. With these, however, the period from 

 date of settling down until young were produced was fairly uni- 

 form varying from 44 to 53 days with an average of 49.5 days. 

 At Plate XLVIII, Fig. 1, some larvse are shown that have just 

 settled down and are about to begin forming scales. 



It is during this period also that the discoloration of the tissue 

 begins. The irregular blotches produced by the young scales 

 individually and collectively on fruit and leaves are shown at 

 Plate XLIX, Fig. 6 and Plate LI, Fig. 2. 



Form<ition of the scale. — In the formation of the scale by the 

 female there were usually apparent four well defined stages 

 based upon its outward appeairance as follows: (1) The white or 

 fluffy stage, (2) the tufted stage, (3) the black stage and (4) the 

 fully formed stage. 



The white or ffuffy stage. — The first indication of the formation 

 of the scale is the secretion of white cottony filaments that cover 

 the body at first sparingly but finally become quite dense until 

 the insect has the appearance of a white oval mass of fluffy cot- 



