60 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table LXII. — Length of feeding 'period of second-brood larvse, Douglas, Mich., .1911, 



summary of Table LXI. 



Number 



Days of 



Number 



Days of 



Number 



Days of 



Number 



Days of 



of larvae. 



feeding. 



of larvae. 



feeding. 



of larva?. 



feeding. 



of larvae. 



feeding. 



1 



20 



7 



32 



4 



44 



2 



56 



1 



21 



9 



33 



8 



45 



2 



58 



4 



22 



5 



34 



5 



46 



1 



59 



5 



23 



4 



35 



• 9 



47 



1 



60 



6 



24 



13 



36 j 



3 



48 



3 



61 



2 



25 



9 



37 1 



3 



49 



1 



62 



5 



26 



9 



38 ! 



4 



50 



2 



64 



2 



27 



4 



39 



3 



51 



2 



69 



4 



28 



8 



40 



2 



52 



3 



70 



7 



29 



7 



41 



3 



53 



1 



71 



3 



30 



3 



42 



3 



54 



1 



76 



10 



31 



8 



43 



2 



55 



2 



84 



Length of feeding period. — The feeding period of the second-brood 

 larva? is considerably longer than has been recorded for the first-brood 

 larva? and is mainly the result of prevailing low temperatures during 

 the late summer and the fall. The data from 199 observations 

 (Table LXI) cover a long period of time extending from July 23, when 

 the earliest larvse hatched, to November 13, when the last larvse left 

 the fruit. There was a range in the length of the feeding period of 

 from 20 to 84 days, with an average of 40 days. 



Time of maturity. — In the rearing cages the first larva? of the second 

 brood left the fruit August 18, but these were not from the earliest 

 eggs. Considering the time of feeding and the date of earliest ovi- 

 position, it is evident that in the field the first larva? left the fruit about 

 August 13. As noted from the band records, the last larva? left the 

 fruit November 13, which was also the last date of observation in the 

 rearing cages. 



BAND RECORDS OF 1911. 



During 1911 the band-record tests were extended to the following 

 five localities: Benton Harbor, New Richmond, Douglas, lake shore 

 (near Douglas), and Pentwater. The purpose of these tests in the 

 widely separated sections of the Michigan fruit belt was to determine 

 the possible existence of differences in the time of development of the 

 codling moth. 



The different band-record orchards were located respectively near 

 Benton Harbor, 7 miles from the lake; at Douglas, on the grounds of 

 the station 2 miles from the lake; at the lake shore, west of Douglas; 

 and near Pentwater, about 7 miles from the lake. Most of the apple 

 trees were old and none of them had been sprayed with poison. The 

 number of trees and varieties of apples, so far as could be determined, 

 were as follows: At Douglas, two trees Golden Russet, one Rhode 

 Island Greening, one crab apple; at the lake shore,, one King, two 

 Canada Red, one Wealthy, one Astrachan, two winter varieties not 

 determined; at New Richmond, two Baldwin, one Transcendent crab 

 apple, one winter variety not determined; at Benton Harbor, one 

 Golden Russet, one Canada Red, one crab apple, three fall varieties 

 not determined ; at Pentwater, six Ben Davis. 



