THE TERRAPIN SCALE. 9 



of the reproductive period. The averages are too long, however, for 

 the first 3 or 4 days of reproduction. 



Table V. — Birth data of 7 larvae of the terrapin scale under favorable conditions, Mont 



Alto, Pa. 



Females. 



Num- 

 ber of 

 larvae. 



Temper- 

 ature 

 at start. 



Embryo 



at 

 orifice. 



Birth 

 com- 

 pleted. 



Time 



re- 

 quired. 



Interval 

 between 

 births. 



Date. 



Degree 

 of ex- 

 haustion 

 of the 

 female. 



Atmos- 

 pheric 

 conditions. 



I 



1 



2 



3 

 1 

 2 

 3 

 1 



F. 

 75 

 75 

 75 

 75 

 75 

 75 

 75 



a. m. 

 7.14 

 7.24 

 7.35 

 7.16 

 7.24 

 7.31 

 8.07 



a.m. 

 7.17 

 7.28 

 7.36 

 7.18 

 7.27 

 7.33 

 8.09 



Minutes. 

 3 

 4 

 1 

 2 

 3 

 2 

 2 



Minutes. 



1913. 

 June 24 



...do 



...do 



...do 



Per cent. 

 70 

 70 

 70 

 70 

 70 

 70 

 70 





I 



11 



8 



Do. 



I 



Do. 



II 



Do. 



II 



9 

 6 



...do 



...do 



...do 



Do. 



II 



.Do. 



Ill 



Do. 







75 







2.43 



8.5 





















Table VI gives data for 7 larvae from two well-exhausted parents 

 under rather unfavorable conditions. These data show an average 

 interval between births of 13.87 minutes. They also show that the 

 interval varies widely in the case of different individuals. 



Table VI. — Birth data for the terrapin scale under unfavorable conditions, Mont Alto, Pa., 



1913. 



Female. 



Num- 

 ber of 

 larvae. 



Tem- 

 pera- 

 ture 

 at 

 start. 



Time 



of 

 birth. 



Interval 

 between 

 births. 



Date. 



Degree 

 of ex- 

 haustion. 



Weather 

 conditions. 



I 



1 



2 

 3 



4 



° F. 



74 

 74 

 75 

 76 



a. to. 

 7.37 

 7.43 

 7.50 

 8.05 



Minutes. 



1913. 

 June 13 



...do 



...do 



...do 



Per cent. 

 70 

 70 

 70 

 70 







6 

 7 

 15 



Do. 

 Do. 



Do. 







75 





9.3 











1913. 

 June 13 



...do 



...do 







n 



1 

 2 

 3 



76 

 76 

 76 



8.03 



8.24 

 8.45 





90 



90 



. 90 



Do. 





20.6 

 20.75 



Do. 

 Do. 



Average for second female. . . 





76 





20.67 

 13.87 









Average for both females 

























THE YOUNG LARV^ IN THE BROOD CHAMBER. 



In the orchard the larvae appear in the brood chambers from 1 to 

 3 days before any of them emerge. During the time of maximum 

 emergence most of the larvae remain in the brood chamber only until 

 the day following birth. If larvae are removed from the brood 

 chamber by overturning the scales they migrate at once to the leaves. 

 Even those that have been born but a few hours do this. The maxi- 

 mum time during which they can remain in the brood chamber 

 depends upon their ability to live without food. Experiments indi- 

 cate that 4 days is the maximum limit of life for unemerged larvae. 



