A PEST OF CURED TOBACCO, EPHESTIA ELUTELLA HUBNER 15 



Tobacco infested by the moth should be promptly fumigated. The 

 writers are conducting experiments in tobacco warehouses with the 

 available fumigants to determine the conditions necessary for the 

 control of this moth in hogsheads and cases of tobacco. The infested 

 tobacco warehouses have been fumigated with hydrocyanic acid gas, 

 which has greatly reduced the number of insects. Further fumigation 

 experiments for the control of this new tobacco pest will be conducted 

 by the Bureau of Entomology. 



The tobacco trade can assist in preventing the spread of Ephestia 

 elutella by reporting new infestations promptly and by arranging for 

 fumigations to be conducted by experienced persons. 



SUMMARY 



Ephestia elutella Hbn. has appeared in the bright-tobacco belt of 

 the United States as a pest of flue-cured tobacco. It has also been 

 recorded as a pest of tobacco in Russia, England, Southern Rhodesia, 

 Poland, Bulgaria, and Greece. 



Female moths were collected from tobacco warehouses on June 22, 

 1931. The progeny of these moths were used in life-history studies 

 in the laboratorv at Richmond, Va., during the summer and fall of 

 1931. 



The duration of the egg-to-adult period of individuals that hatched 

 in June and July ranged from 45 to 95 days, whereas those that 

 hatched in August required 56 to 81 days to complete the cycle. This 

 uneven rate of development makes it difficult to judge the effects of 

 temperature on the insect. 



Data on 30 mated pairs are presented, including daily records of 

 egg laying. The average longevity of the females was 8.7 days, the 

 mean average temperatures ranging from 73.3° to 84.5° F. The aver- 

 age lengths of the different periods were as follows: Preoviposition 

 period, 0.7 day; oviposition period, 6.3 days; postoviposition period, 

 1.7 days. 



The total number of eggs laid by one female ranged from 37 to 279, 

 the average being 127.3. Records of incubation of 3,820 eggs are 

 given, showing the following variations: Average maximum, 7.1 days; 

 average minimum, 4.5 days. The total number of eggs laid by one 

 female during 24 hours ranged from to 90. Most of the egg laying- 

 took place during the first five days of each female's life. 



Larvae usually feed from the stem end of the tobacco leaf toward 

 the tip. They have been found feeding as deep as 8 inches from the 

 staves in hogsheads of tobacco and have demonstrated their capacity 

 to inflict serious damage on leaf tobacco. 



From the data presented it is probable that four generations de- 

 velop from June 1 to October 31 in unheated warehouses in the 

 bright-tobacco belt. 



Moths reared in the laboratory showed a ratio of 46.7 per cent 

 males to 53.3 per cent females, and those collected from infested 

 warehouses a ratio of 60 per cent males to 40 per cent females. 



Microbracon hebetor (Say) was collected while it was parasitizing the 

 larvae of Ephestia elutella, and a small mite, Seius sp., was found 

 attacking adults. 



The work of larvae of E. elutella is contrasted with that of the 

 cigarette-beetle larvae, as an aid to tobacco dealers and manufac- 

 turers in identifvino: infestations. 



