CONTROL OF INSECTS ATTACKING STORED TOBACCO 35 



Cold storage is of great value in preventing or holding in check 

 infestation in connection with factory operations. In many instances 

 when flue-cured cigarette tobacco has fermented satisfactorily the 

 hogsheads or cases are held in storage at around 50° F. to prevent loss 

 of color through excessive fermentation. This temperature prevents 

 activity by the tobacco moth and the cigarette beetle and arrests 

 insect development. 



Cold storage is widely used in the cigar industry for storing manu- 

 factured cigars from the time they are made until they are shipped. 

 The storage chambers vary in size to suit the needs of the individual 

 cigar factory. The temperatures maintained range from about 45° 

 to 55° F., and under these conditions insect infestation is prevented 

 or checked. The cigarette beetle can be killed by exposure to low 

 temperatures. For example, at 36° a 16-day exposure will kill all 

 stages and at 25° a 1-day exposure will produce complete mortality. 

 At a temperature of 40° a 33-day exposure is required to effect complete 

 mortality of the cigarette beetle. 



Program of Control 

 storages 



In periodic atmospheric fumigations of closed warehouses containing 

 domestic and imported tobaccos, a penetration deeper than 3 to 6 

 inches in packed tobacco is rarely obtained. For this reason it is 

 important to keep a check on the population of the insects in all 

 warehouses and to time applications of the f umigant to correspond 

 with the emergence of broods of beetles and moths. Nearly all to- 

 bacco moth larvae when full-grown migrate to the surface of packed 

 tobacco or into sheltered places outside the hogsheads and bales. 

 Larvae of the cigarette beetle also migrate to the surface in large 

 numbers. The adults of neither species feed on tobacco but remain 

 on or outside the containers of tobacco for mating and egglaying. 

 Since the eggs are laid at or near the surface of the packed tobacco, 

 no penetration of gas is required to kill adults, eggs, and many larvae. 

 The emergence of broods of the tobacco moth and the cigarette beetle 

 can be determined rather accurately by using a suction light trap 

 (fig. 13) for an indicator. Another indicator, less suitable but in- 

 expensive, consists of a fabricated board 16 inches long, 10 inches 

 wide, and % inch thick, on which is attached a sheet of sticky flypaper 

 14 inches long and 8 inches wide (fig. 23). 



One of these fabricated-board indicators for each 50,000 to 75,000 

 cubic feet of tobacco warehouse should be installed by suspending it 

 at an angle of about 45 degrees 6 inches below an electric light. A 

 40- watt light is recommended for use over each trap, and only the 

 lights located over the traps should be allowed to burn during the 

 night. In many warehouses the suction light traps (fig. 13) are 

 permanently installed, and the catches from them are used for 

 scheduling fumigations. 



The question of when to fumigate is a difficult one to answer in 

 terms that will apply under all the varied conditions prevailing in 

 storages housing different types of tobacco and having various de- 

 grees of infestation of one or both of the principal pests. In ware- 



