A PEST OF CURED TOBACCO, EPHESTIA ELTJTELLA HUBNER \) 



Table 3. — Data on the life history of 30 mated pairs of Ephestia elutella on flue- 

 cured tobacco in the laboratory at Richmond, Va., 1931 





Date of emergence 









Longevity 





Per 

 cent- 

 age 

 of 

 hatch 



Incubation period 

 of eggs 



Mean 

 average 



Mat- 

 ing 



No. 





Pre- 



ovipo- 



ex- 

 posi- 



Post- 

 ovipo- 







Total 

 eggs 

 laid 









daily 

















temper- 







sition 



tion 



sition 













ature 



Male 



Female 



period 



period 



period 



Male 



Fe- 

 male 



Maxi- 

 mum 



Mini- 

 mum 



Aver- 

 age " 



during 

 life of 





























female 2 



















Num- 



Per 

















Days 



Days 



Days 



Days 



Days 



ber 



cent 



Days 



Days 



Days 



° F. 



1 



July 28 



July 28 







10 



1 



9 



11 



183 



75.4 



5 



4 



4.1 



84.5 



2 



July 31 



July 31 







4 



1 



4 



5 



126 



81.7 



6 



4 



4. 1 



84.2 



3 



-__do 



...do 







4 



1 



3 



5 



108 



94.4 



7 



4 



4.3 



84.2 



4 



Aug. 2^ 



Aug. 2 







5 



2 



7 



7 



104 



86.5 



7 



5 



5.3 



83.5 



5 



--do 



--do 







7 



3 



6 



10 



117 



17.1 



7 



5 



6.0 



82.4 



6 



Aug. 4 



Aug. 4 





4 



1 



7 



6 



76 



92.1 



6 



3 



4.1 



83.3 



7 



Aug. 5 



Aug. 5 





10 



2 



13 



13 



211 



78.1 



7 



4 



4.5 



79.6 



8 



Aug. 6 



Aug. 6 





4 



2 



9 



7 



148 



93.2 



7 



4 



4.3 



80.2 



9 



Aug. 7 



Aug. 7 





7 



2 



12 



10 



138 



65.9 



7 



5 



5.1 



79.1 



10 



Aug. 8 



Aug. 8 





3 



6 



10 



10 



95 



35.8 



8 



5 



6.0 



78.8 



11 



Aug. 7 



-__do 





4 



1 



8 



6 



144 



79.9 



9 



5 



5.3 



78.3 



12 



Aug. 9 



Aug. 9 





3 



2 



10 



6 



134 



63.4 



7 



5 



5.4 



77.1 



13..-. 



Aug. 10 



Aug. 10 







8 



1 



8 



9 



120 



64.2 



8 



4 



5.1 



77.5 



14 



Aug. 11 



Aug. 11 



1 



4 



1 



10 



6 



101 



41.6 



6 



4 



5.3 



76.1 



15 



Aug. 12 



Aug. 12 



3 



3 







5 



6 



37 



78.4 



9 



4 



4.7 



77.5 



16.... 



...do 



.-do 



2 



8 



2 



7 



12 



113 



79.6 



8 



4 



4.5 



75.1 



17 



Aug. 13 



Aug. 13 



2 



7 







11 



9 



103 



68.9 



9 



4 



4.7 



77.1 



18.... 



Aug. 14 



Aug. 14 



2 



5 







10 



7 



144 



56.2 



9 



5 



6.2 



78.7 



19 



...do 



...do 







7 



3 



8 



10 



123 



47.1 



7 



4 



4.6 



75.5 



20 



Aug. 16 



Aug. 16 



1 



7 



2 



8 



10 



84 



1.2 



6 



6 



6.0 



75.0 



21 



Aug. 19 



Aug. 19 







6 



2 



10 



8 



83 



63.8 



8 



5 



6.1 



73.5 



22 



...do 



...do 



1 



8 



3 



8 



12 



93 



24.7 



7 



5 



5.2 



74.6 



23 



Aug. 20 



Aug. 20 







7 



2 



10 



9 



126 



35.7 



8 



5 



6.5 



73.4 



24 



Aug. 21 ! Aug. 21 



] 



7 







12 



8 



99 



71.7 



7 



4 



5.6 



73.3 



25 



Aug. 24 



Aug. 24 



1 



12 







14 



13 



279 



67.2 



7 



4 



5.1 



77.3 



26___- 



—do 



-__do 







7 



3 



10 



10 



109 



44.9 



7 



5 



5.2 



77.3 



27 



Aug. 29 



Aug. 29 







4 



3 



6 



7 



98 



43.9 



7 



5 



5.5 



77.7 



28_.-_ 



Aug. 30 



Aug. 30 



1 



9 



1 



12 



11 



227 



43.6 



7 



5 



5.0 



77.0 



29 



Sept. 4 



Sept. 4 







7 



1 



8 



8 



87 



23.0 



6 



5 



5.3 



77.5 



30-.__ 



Sept. 5 



Sept. 5 







9 



2 



11 



11 



210 



16.2 



5 



5 



5.0 



79.1 



j 



Average 



0.7 



6.3 



1.7 



8.9 



8.7 



127.3 



57.8 



7. 1 



4.5 













1 The average of the incubation records of all eggs laid by one female. 



2 The temperatures recorded in this table were obtained from hygrothermograph records in the laboratory 

 at Richmond, Va. 



INCUBATION PERIOD 



The records of development of 30 eggs laid in June and July, 1931 

 (Table 1), gave the following incubation periods: Maximum, 7 days; 

 minimum, 3 days; average, 4.8 days. For the eggs laid in August, 

 1931 (Table 2), the incubation periods were as follows: Maximum, 6 

 days; minimum, 4 days; average, 5.3 days. The length of the hatch- 

 ing period is greatly influenced by temperature. For example, the 

 maximum period of 7 days (Table 1) occurred during the period June 

 23 to 30, when the mean average temperature was 75.1° F.; whereas 

 the minimum period of 3 days (Table 1) occurred during the period 

 July 7 to 10, when the mean average temperature was 81°. The 

 longest incubation period observed in the laboratory was 17 days, in 

 November, 1931, when the mean average temperature was about 

 55.9°. 



As shown in Table 3, the incubation periods of all hatched eggs 

 ranged from 3 to 9 days, the average being 4.5 to 7.1 days. Obser- 

 vations were made on all of the 3,820 eggs laid by 30 females. 



