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 larvss of the terrapin scale at the leaf ward migration. 



Expe- 

 riment 

 No. 



Num- 

 ber of 

 larvae 

 used. 



Time of start. 



Time of finish. 



Surface. 



Time of observation. 



Num- 

 ber of 

 larvae 

 dead. 



I 



3 

 125 



13 



July 2, 9 a. m.. 

 July 7, 12 noon. 



July 4 , 8.30 

 a. m. 



July 4, 1p.m... 

 July 10, 3.30 p. m. 



July6,8.30a.m.. 



Dead peach twig . . 



Exterior surface 

 of test tube over 

 water. 



Inner surface of 

 test tube over 

 water. 



July 2, 9 a. m 









July 3, 9 a. m 









July 4, 9 a. m 



2 







3 



II 



July 7, 12 noon 



July 8, 8 a. m 





 10 



Ill 



Juiy 9, 7.30 a. m 



July 9, 12 noon 



July 10, 8 a. m 



July 10, 3.30 p. m 



July 4, 8.30a. m 



July 4, 3 p. m 



108 

 110 

 122 

 125 

 









July 5, 8.30 a. m 



5 



7 





July 5, 9 p. m 



7 





July 6, 8.30 a. m 



13 



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



Day of death. 



Experi- 

 ment I. 



Experi- 

 ment II. 



Experi- 

 ment III. 



Dead, by 

 days. 



Per cent 



dead, by 



days. 



First 



; 10 

 2 100 



1 15 



5 

 8 

 



15 

 110 



16 



10.63 





78.01 



Third 



11.34 







Total . 



3 I 125 



13 



141 



99.98 











The summary in Table XVII shows that the average longevity for 

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

 ity 3 days. 



Table XVII. — Maximum longevity of migrating larvse 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. 

 2 days. 



II 



Ill 





Average 





2 days 9J hours. 







