TWO LEAFHOPPERS INJURIOUS TO APPLE NURSERY STOCK. 13 



Table IV. — Length of nymphal stages of the first brood of the apple leaf hopper at West 



Chester, Pa., 1915. 



First brood, June and July. 



























Aver- 



























age 



























mean 



Date 

 of 



First 



First 



Second 



Sec- 

 ond 



stage. 



Third 



Third 



Fourth 



Fourth 



Fifth 



Fifth 



Total 

 nym- 

 phal 

 pe- 



tem- 

 pera- 

 ture 

 for 



hatch- 



molt. 



stage. 



molt. 



molt. 



stage. 



molt. 



stage. 



molt. 



stage. 



ing. 























riod. 



nym- 

 phal 



















































pe- 



























riod. 



1915. 



1915. 



Days. 



1915. 



Days. 



1915. 



Days. 



1915. 



Days. 



191$. 



Days. 



Days. 



°F. 



June 12 



June 15 



3 



June 17 



2 



June 21 



4 



June 25 



4 



June 30 



5 



18 



75.18 



Do... 



June 16 



4 



June 18 



2 



...do.... 



3 



June 26 



5 



July 1 



5 



19 



75.47 



Do... 



June 18 



6 



June 21 



3 



June 25 



4 



June 29 



4 



July 3 



4 



21 



75.79 



Do... 



June 16 



4 



June 19 



3 



June 22 



3 



June 27 



5 



July 1 



4 



19 



75.47 



June 13 



...do.... 



3 



June 20 



4 



June 24 



4 



...do 



3 



July 2 



5 



19 



75.20 



Do... 



June 17 



4 



...do 



3 



June 21 



1 



June 26 



5 



July 1 



5 



18 



75.15 



Do... 



June 18 



5 



...do 



2 



...do 



1 



June 27 



6 



July 4 



7 



21 



75.70 



Do... 



June 16 



3 



...do 



4 



June 25 



5 



June 29 



4 



July 3 



4 



20 



75.52 



Do... 



June 18 



5 



...do 



2 



June 23 



3 



June 27 



4 



July 2 



5 



19 



75.20 



June 14 



June 16 



2 



June 19 



3 



June 21 



2 



June 29 



8 



July 3 



4 



19 



75.20 



Do... 



June 17 



3 



June 20 



3 



June 24 



4 



June 28 



4 



July 2 



4 



18 



74.84 



Do... 



June 18 



4 



...do 



2 



June 23 



3 



...do 



5 



July 3 



5 



19 



75.20 



Do... 



...do.... 



4 



June 21 



3 



June 29 



8 



July 2 



3 



July 6 



4 



22 



75.28 



Do... 



June 17 



3 



...do 



4 



June 23 



2 



June 26 



3 



July 1 



5 



17 



74.77 



June 15 



June 18 



3 



...do 



3 



June 21 



3 



June 28 



4 



July 3 



5 



18 



74.81 



Do... 



...do.... 



3 



...do 



3 



June 25 



4 



June 29 



4 



July 4 



5 



19 



75.05 



Do... 



June 19 



4 



...do 



2 



June 24 



3 



June 28 



4 



July 1 



3 



16 



74.32 



Do... 



...do.... 



4 



June 22 



3 



June 27 



5 



July 1 



4 



July 6 



5 



21 



74.95 



June 18 



June 21 



3 



June 26 



5 



June 29 



3 



July 3 



4 



...do.... 



3 



18 



74.36 



Do... 



June 20 



2 



June 24 



4 



...do 



5 



July 2 



3 



...do... 



4 



18 



74.36 



June 19 



June 21 



2 



...do 



3 



June 26 



2 



June 29 



3 



July 4 



5 



15 



74.06 



June 23 



June 26 



3 



June 30 



4 



July 4 



4 



July 8 



4 



July 11 



3 



18 



75.07 



Average 





3.5 





3 







3.4 





4.2 





" 



18.7 



75.04 







FIRST BROOD OF ADULTS. 



Longevity. — First-brood adults were confined in a Riley cage to 

 determine the length of life. Most of the hoppers died by August 1, 

 as shown in Table V. 



Table V. — Longevity of first-brood adult apple leafhoppers; 50 adults placed in cage 



July 2, 1915. 



Date of examination. 



July 7. . 

 July 8.. 

 July 9.. 

 July 10. 

 Do. 

 July 11. 

 July 12. 

 July 13. 

 July 17. 

 July 24. 



Number 



dead. 



Date of examination. 



July 24. 

 July 26. 

 July 27. 

 July 30. 

 July 31. 

 Aug. 2. 

 Aug. 4. 

 Aug. 5 . 

 Do. 

 Aug. 6 . 



Number 

 dead. 



i Escaped. 



Extent of reproduction. — Two globe cage experiments were made to 

 determine the extent of reproduction by a first-brood female in con- 

 finement. In one cage two pairs of adults, in the other three pairs 

 were confined until death occurred. The average number of eggs 



