30 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



SEASONAL HISTORY. 



Observations on the life history of the grape-berry moth extend 

 over the seasons of 1907, 1908, and 1909. During the latter year 

 special efforts were made to obtain complete records on the develop- 

 ment of the insect in its various stages. In many respects the seasonal 

 conditions during 1907 and 1908 were unusual, the spring of 1907 

 being late and the entire season of 1908 unusually early. The season 

 of 1909 was in most respects normal. 



LIFE-HISTORY STUDIES IX 1909. 



The emergence record of the spring brood of the grape-berry moth 

 was secured from leaves upon which larvae had made cocoons during 

 the fall of 1908. These leaves were left out of doors in a cage all 



4 7 10 13 lb \1 2Z Z5 2,& I 



June 



4 7 10 13 lt> M ZZ 25 28 31 3 i 



July 



Fig. 10.— Diagram, showing time of emergence of spring-brood moths of the grape-berry moth in 1909, at 



North East, Pa. (Original.) 



winter so as to be subject, as nearly as possible/to natural conditions. 

 On May 17, 1909, 1,000 of these cocoons were separated from this 

 mass of leaves and placed in jars in an outdoor rearing shelter (see 

 PL VII, fig. 1) and the following emergence record was secured by a 

 daily examination of the jars and the removal of all moths. 



SPRING BROOD OF MOTHS. 



Time of emergence of spring brood of moths. — Table I gives the emer- 

 gence of all the moths from these jars. The total number of moths 

 to emerge was 507. The number of moths that emerged from June 

 3 to June 14 was 28, or 5.5 per cent; from June 14 to July 14, 455, 

 or 89.8 per cent; from July 14 to August 5, 24, or 4.7 per cent. The 

 maximum emergence occurred June 21. (See fig. 10, showing time 

 of emergence of the spring-brood moths.) 



