38 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



life-cycle period was 40 days, the average length 43.8 days and the 

 longest 53 days. There is a difference of less than half a day in the 

 averages for the two separate rearings. 



SECOND GENERATION. 



Incubation period of second-brood eggs. — For reasons previously 

 assigned the record of egg laying by the moths in confinement is 

 very scanty. Table XII gives the length of this stage for nine eggs 

 of known origin. The incubation period of these eggs is longer than 

 in the record secured for eggs deposited by the spring-emerging 

 moths. The number of eggs recorded, however, is far too small to 

 admit of generalization on this topic. 



Table XII. — Length of incubation of second-brood egos of the grape-berry moth. North 



East, Pa., 1909. 



No. of 

 observa- 

 tion. 



Date- 



Days of 

 incuba- 

 tion. 



No. of 



observa- 

 tion. 



Date- 



Days of 

 incuba- 

 tion. 



Laid. 



Hatched. 



Laid. 



Hatched. 



1 

 2 

 3 

 4 

 5 



Aug. 27 

 Aug. 30 



...do 



Aug. 31 

 Sept. 1 



Sept. 7 

 Sept. 9 

 Sept. 10 

 Sept. 11 

 ...do 



11 

 10 

 11 

 11 

 10 



6 

 7 

 8 

 9 



Sept. 2 

 Sept. 4 



...do 



Sept. 5 



Sept. 12 

 Sept. 13 

 Sept. 14 

 ...do 



10 

 9 



10 

 9 



Days of incubation: 



Average 10. 1 



Maximum 11 



Minimum 9 



Length of feeding period of second-brood larvse. — Tables XIII-XIV 

 give the feeding period of second-brood larvse under two entirely 

 different conditions, namely, larvae reared on green fruit in stock 

 jars under a rearing shelter (Table XIII) and larvae feeding on 

 fruit growing on a vine (Table XIV) in a large outdoor rearing cage 

 (see PL VII, fig. 2). 



Table XIII. — Length of the feeding period of the second-brood larvse of the grape-berry 

 moth under confinement in jars, North East, Pa., 1909. 



No. of 

 observa- 

 tion. 



Larvae 



Larvse 



Number 



No. of 

 observa- 

 tion. 



Larvae 



Larvae 



Number 



hatched. 



left fruit. 



of days. 



hatched. 



left fruit. 



of days. 



1 



Aug. 27 



Oct. 6 



40 



12 



Aug. 30 



Oct. 26 



57 



2 



...do 



Oct. 9 



43 



13 



...do 



Nov. 1 



63 



3 



Aug. 29 



Oct. 17 



49 



14 



...do 



...do 



63 



4 



...do 



...do 



49 



15 



Sept. 11 



Nov. 3 



53 



5 



...do 



Oct. 20 



52 



16 



...do 



Oct. 25 



44 



6 



...do 



Oct. 21 



53 



17 



...do 



Nov. 3 



53 



7 



...do 



...do 



53 



18 



...do 



...do 



53 



8 



Aug. 30 



Oct. 22 



53 



19 



...do 



...do 



53 



9 



...do 



Oct. 25 



56 



Average 





52.6 



10 

 11 



...do 



...do 



...do 



...do 



56 

 56 



Ma 

 Mil 



ximum. . . 





63 

 40- 











