80 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table LXXVII. — Larval instars of the codling moth; head measurements in millimeters 

 for each instar; days duration of instars. Summary of Table IX X VI. 





Head measurements in mm. 



instar. 



per 







Days 



duration of instars. 











1 









1 



Sixth instar. 



.i' 



Observations. 



S \ £ \ S. 



c? 



1 



00 



.s 



GO 



c 



~. 



£ 



. 











Second ins 

 Third insti 

 Fourth Ins 



33 



s = 



3 



"3 



o 



Average 



0.35 



0. 47 0. 66 0. 89 



1.16 



I 1.47 



5.6 



3.6 



4.1 



5.5 



6.1 



8.3 6.4 



44. S 



Maximum 



.35 



.50 1 .70 ! 1.08 



1.30 



1.57 



8 







6 



8 



12 



12 ! 8 



59 



Minimum 



.35 



.45 .60 .80 



1.00 



1.40 



3 



3 



2 



3 



3 



7 4 



33 



111 the course of these studies there was a rather high percentage of 

 mortality, but this was mainly due to the difficulty in properly remov- 

 ing: the larvae from the fruit. 



Table LXXVIII. — Instars of the codling moth larvse of the second brood; head measure- 

 ments in millimeters; days duration of the instars; Douglas, Mich., 1911. 





Date of hatching and molting, and larval head measurements in millimeters. 





No. of 

 observa- 



First instar. 



Second instar. 



Third instar. 



Fourth 



instar. 



Fifth instar. 





Hatched. 



mm. 



First 



molt. 



mm. 



Second 

 molt. 



mm. 



Third 

 molt. 



mm. 



Fourth, 

 molt. 



mm. 



1 



Julv 29 



...do 



...do 



...do 



Aug. 2 

 ...do 



Aug. 6 



...do 



do 



3: 

 > 



Aug. 2 

 Aug. 3 

 ...do 



...do 



Aug. 7 

 Aug. 8 

 Aug. 10 



...do 



0.45 



Aue. 6 



0.75 

 11.00 



.78 

 .76 

 . 75 

 .70 



Aug. 11 

 Aug. 12 



0.81 

 11.22 





2 



. 45 Aug. 7 

 . 49 Aue- S 





3. . 





4 



.54 

 .46 

 .46 

 .43 

 .49 



Aug. 6 

 Aug. 13 

 Aug. 15 









5 









6 









7 









8 











9 











Aug. 18 

 Sept. 2 

 Aug. 31 



1.22 



10 



11 



Aug. 7 

 Aug. 11 

 Aug. 12 



...do 



...do 



do 





Aug. 20 



.66 



.76 



Aug. 27 

 ...do 



i 1.08 

 i 1.19 



i 1.51 

 1 1.51 



12 



Aug. 20 .50 

 Aug. 17 : .46 



...do ! .46 



Aug. 28 .50 

 Aug. 26 .49 

 Aug. 23 .49 

 Aug. 19 .51 



...do 







13 



Aug. 25 

 Aug. 24 



.68 

 .67 







14 



15 



Sept. 1 





16 



...do 



Aug. 14 



...do 



Aug. 15 

 Aug. 16 

 Aug. 18 



...do 



Aug. 24 



Aug. 2S 



...do 



...do 



.71 

 .66 

 .67 







17 



Sept. 7 





18 







19 







Sept. 1 



1. 19 



20 



Aug. 25 

 Aug. 28 

 Aug. 25 



.50 

 .42 

 .46 



Sept. 2 



.67 









21 









22 



Sept. 2 



.60 









23 



Sept. 8 



.80 

 .81 



Sept. 15 

 Sept. IS 



1.08 



24 









1.08 















1 Abnormal and not included in the summary. 



