A PEST OF CURED TOBACCO, EPHESTIA ELUTELLA HUBNER 11 



females preferred to oviposit on tobacco rather than on the glass vial, 

 practically all the eggs laid being attached to the tobacco leaf. 



The daily lots of eggs were left on the tobacco leaf and examined 

 every 24 hours for hatching. The hatched larvae were separated each 

 day from the unhatched eggs and the number recorded. This pro- 

 cedure was followed in handling all daily lots of eggs to obtain incuba- 

 tion records. The unhatched eggs of each lot were examined for 10 

 days after the last hatch was recorded. By this time all unhatched 

 eggs had become dried, shrunken, and distorted in shape, and it was 

 apparent that further observations were unnecessary. 



The percentages of hatch for all eggs recorded in Table 3 ranged 

 from 94.4 per cent to as low as 1.2 per cent, the average for the 3,820 

 eggs being 57.8 per cent. The average of all the incubation periods 

 (Table 3) was: Average maximum, 7.1 days; average minimum, 4.5 

 days. The mean average daily temperature during the period of 

 longevity was calculated for each female and ranged from 73.3° 

 to 84.5° F. 



The preoviposition periods ranged from less than a day to 3 days, 

 the average being 0.7 day. The oviposition period ranged from 3 to 

 12 days, averaging 6.3 days; and the postoviposition period ranged 

 from less than a day to 6 days, averaging 1.7 days. 



The longevity of female moths ranged from 5 to 13 days, the 

 average being 8.7 days. In most instances high temperature reduces 

 the length of life of females. However, there are exceptions, as shown 

 in Table 3. For example, females Nos. 2 and 3 each lived for 5 days 

 at a mean temperature of 84.2° F., while female No. 1 lived 11 days at 

 a mean temperature of 84.5°. Laboratory records show that six 

 females that emerged and mated in November had an average 

 longevity of 14.6 days when the mean temperature was 59.2°. 



The total number of eggs laid ranged from 279 (laid by female 

 No. 25) to 37 (laid by female No. 15), the average being 127.3. Owing 

 to the variation in the number of eggs laid, no conclusions regarding 

 the effects of temperature on egg laying can be drawn from these data. 



EGG LAYING 



The small grayish-white eggs of Ephestia elutella were ordinarily 

 laid on the tobacco leaves. The eggs, when laid, are covered with a 

 gluey coating, which usually attaches them to the leaves. The 

 number of eggs laid during 24 hours was variable. The daily egg- 

 laying records of the females listed in Table 3 are presented in Table 4. 

 As shown in this table, the number of eggs laid during 24-hour periods 

 by one female ranged from to 90. Female No. 11 laid 90 eggs on 

 August 10, when the temperature ranged from 91° to 78° F. More 

 eggs were laid the second day after emergence than on any other day 

 and most of the egg laying took place during the first five days of the 

 life of each female. 



