158 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table XLVL- 



Second-brood eggs. Incubation period of eggs laid in the rearing 

 cages — Continued . 



No. of 

 apple. 



Red rimi. 



Black spot. 



Num- Date of 

 ber of deposi- 



eggs. lion. 



Aug. 



..do 



..do 



Date of Num- Date of < Num- 



appear- ber of I appear- ber of 



anee. | eggs. t ance. eggs. 



Aug. 31 



..do 



..do 



Sept. 1 



Aug. 30 { S $; T 



. ... /..do 



!1 \Sept. 7 

 Sept. 4 



...do. 



...do. 



** 1 @pt' 

 ...do 



Sept. 3 



Sept. 4 

 Sept. 12 



(Sept. 

 {Sept. 

 [Sept. 



Sept. 



Sept. 

 (Sept. 

 {Sept. 



I Sept. 4 



[Sept 

 ..do 

 ..do 



8 



9 



|Sept. 11 



/Sept. 8 

 (Sept. 9 



(Sept. 7 

 {Sept. 8 

 ISept. 9 

 /Sept. 7 

 \Sept. S 



...do 



/..do 



\Sept. 9 

 Sept. s 

 Sept. 10 

 Sept. 11 

 Sept. 12 

 Sept. 10 

 Sept. 12 



..do 



..do 



jsept. 



13 



>..do 



Sept. 15 



Sept. 22 



Hatched. 



Date of 

 appear- 

 ance. 



Sept. S 

 Sept. 9 

 Sept. 10 

 Sept. 9 

 Sept. S 



[sept. 11 

 (Sept. 12 



|Sept. 10 

 {Sept. 11 

 (Sept. 12 



I Sept. 9 

 fSept. 10 



I do 



/ 

 Sept. 11 



...do 



Sept. 12 

 Sept. 11 



Isept. 13 

 [Sept. 14 



Sept. 13 

 Sept. 14 



...do 



...do 



Sept. 15 



/..do 



\Sept. 16 

 Sept. 17 

 Sept. 18 

 Sept. 25 



Num- 

 ber of 

 eggs. 



Length 

 of egg 

 stage. 



Days. 

 12 

 13 

 14 

 13 

 12 



14 

 15 



13 

 14 

 15 



12 

 13 



From Table XLVI it will be seen that the average egg stage was 

 12.5 days, the later individuals remaining in the egg slightly longer 

 than the earlier, a phenomenon probably due to the gradual lower- 

 ing of the temperature. Out of 845 eggs deposited, 760, or a frac- 

 tion under 90 per cent, hatched. As can be seen from a study of 

 Table XLVI the red ring is not a constant factor in the egg develop- 

 ment, since it could be discovered in only 610 individuals. Mortality 

 is about equally great before and after the appearance of the black 

 spot. Table XLYII shows the variations in the length of the egg 

 stage; as recorded in Table XLVI. 



Table XLVII. — Second-brood eggs: Variations in the length of the egg stage as recorded 



in Table XL VI. 



Table XL VIII is a summary of Table XLVI and shows the aver- 

 age, maximum, and minimum length of the egg stage. 



