CODLING MOTH IN CENTRAL APPALACHIAN REGION. 



41 



Table XXXVII. — Resume of rearing experiments on the codling moth at four points in 

 Virginia, West Virginia, and Maryland in 1913. 



Observation. 



Ilagers- 



town, M'd. 



Num- 

 ber. 



Per 

 cent. 



Winches- 

 ter, Va. 



Num- 

 ber. 



Per 

 cent. 



Charlottes- 

 ville. Va. 



Num- 

 ber. 



Per 



cent. 



French 

 Creek, 

 W. Va. 



Num- 

 ber. 



Per 

 cent. 



Total. 



Num- 

 ber. 



Per 



cent. 



100.00 



31.46 

 19.58 



47.38 

 1.55 



Larvae collected 



Larvae dying from handling, cannibal- 

 ism, etc... 



Mot h s emerging same season 



Wintering larvae 



Parasitized larvae 



2,756 



883 

 227 



L.tilti 



100.00 



32.04 



8.24 

 59.72 



100.00 



24.10 



33.57 



35.63 



6.70 



100.00 



41.14 



49.82 



9.04 



100.00 



33.58 



28.67 



35.66 



2.09 



4,412 



1,388 



864 

 2,092 



It will be noted that the proportion of larvae dying in the rearing 

 cages, due to handling, cannibalism, disease, etc., varied from 12.90 

 per cent to 41.14 per cent. The latter figure, however, is unduly 

 high, the average loss from this source being 21.12 per cent in 1912 

 and 31.46 per cent in 1913. The proportion of larvae transforming 

 the same season as that in which they were collected varied from 

 8.24 per cent at Hagerstown to 49.82 per cent at Charlottesville, 

 with an average of 19.12 per cent in 1912 and 19.58 per cent hi 1913. 

 For 1912 from 42.86 per cent to 67.14 per cent of all larvae collected 

 spun up and wintered, the average for all points being 59.42 per 

 cent. The proportion of wintering larvae in 1913 was abnormally 

 small on account of the light fruit crop of that year. Loss from 

 winterkilling amounted to from 11.21 per cent to 41.38 per cent, 

 the average for all points being 26.06 per cent. Observations on 

 parasitism were made only at Winchester and French Creek, the 

 highest recorded being 6.70 per cent at Winchester in 1913. It must 

 be remembered, however, that the foregoing facts are taken from 

 observations of insects kept in confinement, and only in a limited 

 way indicate what occurs under normal out-of-door conditions. 



Table XXXVIII gives the numbers of codling-moth larvae col- 

 lected and reared in the course of the work in the different localities. 



Table XXXVIII. — Number of codling -moth larvx collected and reared in the different 

 localities in Virginia, Maryland, and West Virginia during 1911, 1912, and 1913. 



Locality. 



Year. 



Number of 

 larvae col- 

 lected and 

 reared. 



Locality. 



Year. 



Number of 

 larvae col- 

 lected and 

 reared. 





1911 

 1912 

 1913 

 1911 

 1912 

 1911 

 1912 

 1911 

 1912 

 1913 



1,218 



'905 



542 



1.979 



1,862 



910 



1.418 



2,079 



798 



971 



Hagerstown, Md 



1911 

 1912 

 1913 

 1911 

 1912 

 1913 

 1911 

 1912 



1.761 





French Creek, W. Va 



1.706 



2. 756 

 633 







339 

 143 





399 



Winchester, Va 



Total 



47 









20, 466 











