CONTROL OF INSECTS IN TOBACCO 15 



The cigarette beetle is attracted to light, and a suction light trap 

 aids appreciably in reducing populations of this insect. The tobacco 

 moth is not attracted to light, but any insect flying close to the mouth 

 of the trap is caught by the suction. Consequently, although a trap 

 may not significantly reduce the population of tobacco moths, it does 

 catch a sufficient number to reflect the degree of infestation and to 

 indicate the beginning, peaks, and end of seasonal activities of the 

 insect, 



A trap, preferably mounted on a cord and pulley so that it can be 

 readily lowered for examination, should be suspended from the ceiling 

 of the warehouse above the top of the hogsheads or bales of tobacco. 



If traps are to be used as an aid to control the cigarette beetle, 

 one trap for each 100,000 to 150,000 cubic feet of space is necessary. 

 In small storage units one trap per unit should be used. For use 

 merely as a measuring device to record the relative insect population, 

 one trap per one-story warehouse is satisfactory in storages up to 

 300,000 cubic feet. 



All traps should be operated 24 hours a day. Operation for only 

 a part of a day will not give an adequate sample. 



An indicator that is simpler, but less satisfactory, than suction 

 light traps, consists of a fabricated board about 16 inches long by 

 10 inches wide on which a sheet of sticky flypaper is fastened. The 

 board is suspended at an agle of 45°, and 6 inches below a 40- or 50- 

 watt electric light, One of these indicators should be used for each 

 50,000 to 75,000 cubic feet of space. Lights over the flypaper should 

 not be turned off at night. The sticky flypaper should be replaced 

 weekly. 



A little more elaborate and more effective form of flypaper trap 

 is sometimes used in the cigar industry. It consists of a boxlike frame 

 with flypaper fastened on four sides and a 40- to 50-watt light bulb 

 suspended in the center. 



Screening 



During the summer adults of both the cigarette beetle and the to- 

 bacco moth are constantly flying about, Therefore, all warehouses 

 should be screened, particularly open warehouses where sprays are 

 used (fig. 9). In an unscreened warehouse insects may readily fly out 

 of the building ahead of the spray, only to return within a few min- 

 utes after the spraying is done. Furthermore, even should all beetles 

 and moths in a storage be killed, the building will probably become 

 reinfested in a few hours. Observations have been made in screened 

 warehouses where one building was very lightly infested and an ad- 

 joining building remained very heavily infested all summer. Such 

 differences would rarely if ever appear in unscreened storages. 



Over a period of years it has been shown that space sprays give 

 significantly better control of the tobacco moth in screened than in 

 unscreened warehouses. Galvanized- wire screen may be used, but will 

 usually rust out. in 3 to 5 years. A more durable wire, such as copper, 

 bronze, or plastic, will probably prove more economical in the long 

 run. The size of mesh, used is important. To exclude the cigarette 

 beetle the openings in the wire should not exceed 0.0396 inch. A 20- 

 mesh wire (20 strands to the inch) is preferable, but an 18-mesh wire 

 is satisfactory if the wire strands are at least 0.02 inch in diameter. 



