THE CODLTXG MOTH TX MICHIGAN. 



81 



Table LXXVIII.— instars of the codling moth larvae of the second brood; head measure- 

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



Date of hatching and moltins, 

 and larval head measurements 

 in millimeters— Continued. 



No. of 

 observa- 

 tions. 



Sixth instar. 



Fifth 

 molt. 



Left 

 fruit. 



Pupa- 

 tion, 

 sLxth 

 molt. 



Davs duration of instars. 



Sixth instar. 



First Second Third Fourth Fifth 



instar. instar. instar. instar. instar. Feed- Water- 

 ing, i ing. 



1.81 Aug. 31 



Sept. 18 



Sept. 10 



8 _ 



9 Aug. 26 



10 



11 :. 



12 



13 



14 



15 



16 



17 



18 



19 ■ Sept. 6 



20 ' I. 



21 . 



22.. i I ! 



23 Sept. 27 1. 62 j Oct. 20 



24 Oct. 1 ! 1. 52 Oct. 18 | 



1.57 i Sept. 18 





4 

 5 

 3 

 6 



5 









......'. 



5 











5 





















:::;::; 





6 













4 .. 















4 









8 

 ( 2 ) 

 ( 2 ) 



5 



( 2 ) 







i 



6 

 4 











8 .. 













8 

 7 















8 











16 .. 











14 



2 

 5 

 9 











9 i 



10 



























« 



12 



( 2 ) 



& 



8 

















8 















7 



10 



12 

 13 



23 



17 



(2) 







(2) 













1 Abnormal and not included in the summary. 



- Wintered. 



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

 for each instar; duration of instars; summary of Table LXX VIII. 



Observations. 



Head measurements in mm. 

 instar. 



per 





Days duration of 



instars. 







i 



8 









pa •-.' 



a 





= 



| 



I ins 

 inst 



a 



a 



C2 



X 





— X 



•= 



"x 



- 



- 



r ~ r; __ 



£ 



*= 



5 ~ H 



sz 



- 































— 



'1 '— 



— 



— 



X 



— 



x — 



— 



— 



X 



Average 



0.35 



0.47 



0.70 



0.81 



1.14 



1.63 



- 



5.8 



7 



- 



9.5 



14.2 



Maximum 





.54 



.78 



.81 



1.08 



1.81 



16 



9 



10 



10 



13 



23 



Minimum 





.42 



.60 



.80 



1.22 



1. 52 



4 



2 







4 











The records for the time of molting and the head measurements for 

 the separate instars for the first brood are given in Table LXXYI. 

 Of a total number of 14 larva?, 8 attained full growth. Of these. 

 2 passed through five instars and 6 through six instars. A single 

 larva (Xo. 8) that appeared stunted in its growth had seven instars, 

 but failed to reach maturity. One full-grown larva of this brood 

 wintered, while 7 resulted in moths the same year. Larva? Xos. 11 to 

 14, inclusive, were left undisturbed during then early stages in order 

 that their development should not be unduly delayed. 



