THE TOBACCO BEETLE. 37 



recorded as attacking the tobacco beetle in all stages except the adult, 

 in the Philippines (77). It is not uncommon to find mites of the 

 genus Tyroglyphus feeding on dead larvae and pupae of the tobacco 

 beetle. It is probable that live stages of the tobacco beetle are not 

 attacked and that the mites present in these instances are merely 

 acting as scavengers. 



At Key West, Fla., a species of jointed spider of the order Sol- 

 pugida and a small arachnid belonging to the order Pseudoscor- 

 piones were found by the writer to destroy larva? of the tobacco beetle. 

 While these arachnids may destroy a considerable number of beetles 

 and do no particular damage to the leaf tobacco, the work of the sol- 

 pugid in cigars would hardly be considered beneficial, as the cigars 

 are badly torn by the spider in its efforts to dig out the larvae. The 

 nature of this injury is shown in figure 12. 



REMEDIAL MEASURES. 



COLD STORAGE. 



A readily available and effective means of treating infested to- 

 bacco is found in the modern cold-storage plant. This treatment 

 has been used to a considerable extent, but usually the temperatures 

 in operation have the effect of suspending insect activity rather than 

 of causing death. The beetles become inactive at temperatures be- 

 low 65° F., and the storage of infested materials at temperatures 

 between 32° and 65° F. prevents further damage as long as the ma- 

 terial is held in storage. When lower temperatures are available a 

 more satisfactory and effective method, although somewhat more 

 expensive, is to subject the tobacco for a week or more to the lowest 

 temperature that can be obtained. Cigars or manufactured tobacco 

 should either be removed from cold storage when the air is dry, to 

 prevent " sweating," or the temperature should be raised gradually 

 before removal. Air-tight receptacles for holding the cigars or to- 

 bacco and an atmosphere as dry as can possibly be secured are desir- 

 able when the cold-storage method is used. If the material is re- 

 moved when the air is damp the condensation of moisture may cause 

 the boxes to be discolored or develop mold in the tobacco or cigars. 



A large number of cigars in boxes, placed in cold storage, were 

 kept under observation by the writer. These cigars were not put in 

 sealed containers but were merely placed in piles on the floor of the 

 cold-storage room. They were removed when the air outside was 

 dry and cool, put under presses in a dry room, and left for a 

 time to prevent warping of the boxes. The treatment proved thor- 

 oughly effective in sterilizing the cigars, and the manufacturer re- 

 ported that no injury was apparent. Different lots were kept at a 

 temperature of about 12° F. for from one to four weeks. 



