THE TOBACCO BEETLE, H 



ing the day the beetles will be found most numerous in secluded 

 places, such as crevices in the walls or in the leaf tobacco. They 

 have a habit of feigning death when disturbed. The adults generally 

 begin to mate the second or third day after becoming fully mature. 

 In tobacco warehouses the beetles seldom are found active at tempera- 

 tures below 65° F. Activity increases as the temperature becomes 

 higher, but ceases between 117° and 120° F. 



Length of the adult stage. — In warm rooms, or in summer, the 

 beetles die much sooner than when emergence occurs during cooler 

 weather. Although they may gnaw through tobacco or other food 

 substances to escape from the locality where transformation took 

 place, little evidence of feeding has been observed. Adults have been 

 found to lay eggs and li^^e the normal length of time whether food 

 was present or not. Under usual conditions they live from three to 

 six w^eeks. 



Oviposition. — Egg laying usually begins in from two to six days 

 after emergence. In warm places where tobacco is not subjected to 

 temperatures much below 70° F., Qgg^ may be found at any time. In 

 the Middle and Northern States, where tobacco is kept in unheated 

 buildings and the temperature is about the same as out of doors, the 

 eggs are laid only during the warmer months of the year. In experi- 

 ments at Richmond, Va., the last eggs were obtained from beetles 

 kept in an unheated building on October 28, 1914, and the first eggs 

 were obtained the following spring on May 2. There seems to be 

 a rather comrhon belief that the eggs are laid on the leaf of tobacco 

 in the fields or during the process of curing, and that these eggs do 

 not develop until the tobacco is handled or made up into cigars or 

 other products. This is not the case, as the eggs at ordinary tem- 

 peratures hatch a fcAV days after they are laid, and the beetle does not 

 infest tobacco until after it is cured. The eggs adhere very lightly 

 to leaf tobacco and are dislodged easily by handling. The beetles 

 deposit their eggs in crevices or folds of the leaf, or in secluded places 

 away from the light, and where the closely packed food substance 

 protects the eggs from evaporation. The egg-laying period normally 

 lasts from 2 to 17 days, and the number laid by each female is ap- 

 proximately 25 to 30. 



SUMMARY OF LIFE HISTORY. 



The insect lives in its food substance during all stages of its exist- 

 ence. In tobacco or other food substance kept constantly warm breed- 

 ing is continuous, and there may be as many as five or six generations 

 a year. Under usual conditions in tobacco warehouses in the latitude 



