THE TEEEAPIN SCALE. 



21 



the migrating larvae can live from 2 to 3 days. More than 78 per 

 cent of the larvae died upon the second day, and the mortality of the 

 remainder was about equally divided between the first and third day. 

 It was apparent that the third day was of very little value to the 

 larvae as they were in a state of collapse. 



Table XV. — Longevity of larvse of the terrainn scale at the leafward migration. 



Expe- 

 riment 

 No. 



Num- 

 ber of 

 larvaj 

 used. 



Time of start. 



Time of finish. 



Surface. 



Time of observation. 



Num- 

 ber of 

 larvsE 

 dead. 



I 



3 

 12.5 



13 



July 2, 9 a. m. . 

 July 7, 12 noon. 



July 4 , S..30 

 a. m. 



Jiily •!, Ip. ra... 

 July 10, 3.30 p.m. 



Jnly6,S.30a.ra.. 



Dead peach twig . . 



Exterior surface 

 of test tube over 

 water. 



Inner surface of 

 test tube over 

 water. 



July 2, 9 a. ra 









July 3, 9 a. ra 









July 4, 9 a. m. . 



2 





July 4, 1 p. ra. . . 



3 



II 



July 7, 12 noon 



July 8, 8 a. m 





 10 



Ill 



Jmy 9, 7.30 a. m 



July 9, 12 noon 



July 10, 8 a. m 



July 10, 3.30 p. m 



July 4, 8.30 0. m 



July 4, 3 p. m 



108 

 110 

 122 

 125 

 









July 5, 8.30 a. m 



July 5, 4 p. ra. . . 



5 



7 





July 5,9p.m 



7 





July 6, 8.30 a. ra 



13 



Table XVI. — Daily mortality of larvae, of the terrapin scale from data in Table XV. 



Day of death. 



Experi- 

 ment I. 



Experi- 

 raent II. 



Experi- 

 ment III. 



Dead, by 



days. 



Per cent 



dead, by 



days. 



First 



10 

 2 100 



1 [ 15 



5 



I 



15 

 110 

 16 



10.63 





78.01 



Third 



11.34 







Total 



3 



125 



13 



141 



99.98 







The summary in Table XVII shows that, the average longevity for 

 the three experiments was 2 days 9^ hours and the maximum longev- 

 ity 3 days. 



Table XVII. — Maxivium longevity of migrating larvae of the terrapin scale from 

 experiments given in Table XV. 



Experiment. 



Number of 

 specimens. 



Longest life. 



I 



3 



125 



13 



2 days 4 hours. 



3 days. 



II 



Ill 



2 days. 





Average 





2 days 9J hours. 







