22 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 
follows: Number of pairs of beetles under observation, 44; average 
length of life of males kept without food, 23.4 days; average length’ 
of life of males kept with food, 21 days; average length of life of 
females kept without food, 31.2 days; average length of life of 
females kept with food, 30.5 days. 
Another series of experiments was made to determine the length 
of life without food at ordinary room temperatures in summer. 
Twenty-three pairs of beetles were placed in separate tubes directly 
after emergence. The average length of life was 21 days for the 
males and 40.4 days for the females. Records from 24 pairs of 
beetles kept under observation at Clarksville, Tenn., during August 
and September, 1916, by Messrs. J. E. McMurtrey and E. H. Vance 
show an average length of life of 17.7 days for males and 21.4 days 
for females. An average of 30 eggs per female was obtained. The 
greater number of eggs was deposited between the third and the 
eighth day after egg-laying began. The period of oviposition 
ranged from the first until the seventeenth day after mating was 
observed. A similar experiment during the same period with 18 
pairs of beetles kept without food gave the following: Average num- 
ber of eggs deposited per female, 24; average number of days males 
lived, 21.2; average number of days females lived, 26.3. 
OVIPOSITION. 
Egg-laying usually begins in from 2 to 6 days after emergence. 
A large proportion of the females kept under observation commenced 
laying eggs the second and third day after mating. Indoors, where 
infested material is kept warm and is not subjected to much varia- 
tion in temperature, the eggs may be found at any time. Humidors 
for storing cigars and tobacco usually are in steam-heated buildings, 
and the warmth and moisture conditions foster continuous reproduc- 
tion throughout the year. Eggs usually are not deposited at tem- 
peratures below 70° F. The adults are more active at high tempera- 
tures, and eggs are most abundant in tobacco during the warmer 
period in summer. In the Middle and Northern States, when to- 
bacco is subjected to approximately out-of-door conditions of tem- 
perature in unheated buildings, the eggs are laid only during the 
warmer months of the year. At Richmond, Va., the last eggs were 
obtained on October 28, 1914, from beetles kept in unheated build- 
ings and the first eggs were obtained on May 2 of the following 
spring. Under ordinary conditions the eggs are deposited singly, 
usually in depressions or folds of the food substance. Owing to their 
smal] size and secluded location they do not ordinarily attract atten- 
tion. Even to many who are thoroughly familiar with other stages 
of the beetle in tobacco the egg is an unfamiliar object. 
