D CIRCULAR 269, U. S. DEPT. OF AGRICULTURE 



and that the rapidity of flight is much greater at night. In the day- 

 time the moths are attracted to dim lights and are most numerous 

 in the shadows cast by rows of hogsheads. 



LIFE HISTORY AND HABITS 

 APPARATUS AND METHOD OF STUDY 



Female moths of the spring brood were collected in tobacco ware- 

 houses during the period -June 22 to July 14, 1931, and records of 

 their egg laying on flue-cured tobacco were made. The females were 

 probably fertilized when collected; however, males were placed with 

 them during the oviposition period. The progeny of these moths 

 were used to secure the life-history data tabulated in this circular. 



In order to obtain egg-laying records, the females were placed in 

 individual glass vials, each containing portions of leaves of flue-cured 

 tobacco. The vials used were 4% inches long and 1 inch in diameter, 



Figure 5.— Adult of Ephestia elutella, X 9 (approximately). When the wings are folded the adult 

 measures about three-eighths inch from head to tip of wing. (Munro and Thomson) 



and had close-fitting metal caps. Fresh pieces of tobacco were placed 

 in the vials every 24 hours, and the eggs were counted with the aid of 

 a binocular microscope. During the incubation period the daily lots 

 of eggs, usually attached to the leaves, were left in the vials. 



The larvae were reared in circular pasteboard pill boxes 1% inches 

 in diameter and three-fourths inch deep. As food for the larvae, por- 

 tions of flue-cured tobacco leaves and tobacco which had been ground 

 through a 48-mesh screen were used. It was found that young larvae 

 had difficulty in feeding on the tobacco leaves after some of the mois- 

 ture had evaporated. This difficulty was overcome by using the 

 ground tobacco in the rearing containers. 



The temperatures recorded in Table 1 were obtained from the rec- 

 ords of the United States Weather Bureau for Richmond, Va. The 

 other temperatures recorded were obtained with a hygro thermograph 

 located in the laboratory. 



