82 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



The observations on the molting habits of the second brood of 

 larva? (Table LXXVIII) were not all completed, as at times some of 

 the larva? were neglected on account of the stress of other work. 



Table LXXX. — Head measurements of first-brood and second-brood codling moth larva:, 

 collected from banded trees at Douglas, Mich., 1911. 





First 





Second 





First 





Second 



No. of 

 larvae. 



brood 



larvae. 



collected 



No. of 

 larvae. 



Lrood 



larvae. 



collected 



No. of 

 larvae. 



brood 



larvae. 



collected 



No. of 



larvae. 



brood 



larvae. 



collected 





July 13. 





Sept. 17. 





July 13. 





Sept. 17. 





mm. 





mm. 





mm. 





mm. 



1 



1.70J 



1 



1.57 c? 



16 



1.62 c? 



16 



1.78c? 



2 



1.50? 



2 



1.62 c? 



17 



1.83 9 



17 



1.73 c? 



3 



1.56 c? 



3 



1.84 9 



IS 



1.51c? 



18 



1.73 c? 



4 



1. 70 $ 



4 



1.78 9 



19 



1. 80 9 



19 



1.62 c? 



5 



1.70 c? 



5 



1.57 9 



20 



1.62 c? 



20 



1.73 9 



6 



1.62 c? 



6 



1.84 9 



21 



1.56 c? 



21 



1.73 9 



i 



1.56 9 

 1.29 9 



7 



1.68 9 



22 



1.62 9 



22 



1.73 c? 



18 



8 



1.62 c? 



23 



1.67 9 



23 



1.78 c? 



9, 



1.62 9 



9 



1.78 9 



24 



1.62c? 



24 



1.62 c? 



10 



1.70 c? 



10 



1.84 9 



25 



1.709 



25 



1.89 9 



11 



1.79 c? 



11 



1.68 c? 



26 



1.70 c? 



26 



1.78 9 



12 



1.56 9 



12 



1.68 c? 



27 



1.62 c? 



127 



1.27 9 



13 



1.62 c? 



13 



1.68 9 



28 



1.62 9 



28 



1.67 c? 



14 



1.56 c? 



i 14 



1.29 9 



29 



1.S0 9 



29 



1.67 9 



15 



1.56 9 



15 



1.73 9 



30 



1.65 9 



30 



1.89 c? 



1 Parasitized larvae. 



The results from these observations are, however, similar to those 

 previously obtained. 



The pink color which is characteristic of the mature larva first 

 appeared a few days after the final molt. A number of mature first 

 and second brood larvae collected in the field were measured for a 

 comparison with those maturing in the laboratory. The records of 

 Table LXXX show no material difference in the size of head of the 

 larva? of the two sets except that the field larva? are slightly larger, 

 which is to be expected, since the latter have developed normally and 

 without any interference. 



Table LXXXI. — The average widths of the head of the larva in its successive instars and 

 the rate of increase at each molt; summary of Tables LXXIV-LXXIX . 



Instars. 



1910, sec- 

 ond brood. 



1911, first 

 brood. 



1911, sec- 

 ond brood. 



Average. 



Average 



increase 



at each 



molt. 



First 



mm. 



0.33 



.48 



.68 



.94 



1.24 



1.54 



mm. 



0.35 



.47 



.66 



.89 



1.16 



1.47 



mm. 



0.35 



.47 



.70 



.SI 



1.14 



1.63 



m m . 



0.34 



.47 



.67 



.88 



1.18 



1.55 



m m . 

 0.13 





.20 



Third 



.21 



Fourth . . . 



.30 



Fifth 



.37 



Sixth 









