THE rrLTVRE OF TOBACCO. 71 



these weeds serve as lireeding yjlaees for the eai'lier lirnmls uf this 

 1)eetle. 



When the Vieetle once starts its work r>n the eiop, its lavages 

 may be cheeked by the same Paris green spray that has been 

 recommended fur the other insects. 



Lasioderma Serrieorne, Fabr. A Beetle Injurious to Stored 



Tobaeeo. — This beetle feeds u|)on all foj-ms of stni-ed tobacco, and 

 works injury by eating it full of holes. Cigars, cigaiettes, and 

 stored leaf of all kinds are equally enjoyed by this pest. <Jnce it 

 has taken possession of a cui-ing barn, wai-ehouse, factoiy <ii- shop, 

 it is there to stay, unless strenuous measures are adopted. In the 

 warehouse the passing of the tobacco thiough the heat of the re- 

 oi'dering machine will check the ravages somewhat, and the steaming 

 of every portion of the i-oom will serve as a tempjoraiy measure ; 

 but a few insects will be hidden in the cracks of the flooi and wall, 

 and serve to again infest the liuilding. 



Carbon di -sulphide has been recommended by Di'. Howard, of 

 the United States Department of Agriculture, as a treatiuent for 

 this beetle. The room is made as air-tight as possible, and the 

 fumes of this gas are confined in it foi' at least twenty-four houis. 

 The gas is explosive when confined, and is also deadly to all life, 

 and for this leason no fiie or peisi.ms are allowed in (>i' near the 

 liuilding during the treatment, and the room is thoroughl}' aired 

 before lieing again entered. In a tobacco shop all of the tobacco may 

 lie placed in a case and treated. One pound of the liquid for every 

 thousand feet of space is placed in a vessel and permitted to evapo- 

 rate in the room. 



Other Tobaeeo Insects. — Other insects, as the grasshopper 

 and the cricket, often do some damage to the tobacco crop. Any 

 insect that injures the plant by eating can be destroyed by the 

 use of arsenical poisons, as Paris green. However, if the insect 

 secures its food by sucking, as do the true bugs {Hemiptera), it will 

 be impossible to destiny with the arsenical poisons, and some spray 

 will have to be applied that will kill the insect by contact. For 

 the sucking insects the use of a concentrated solution of nicotine, 

 diluted with sixty parts of water, has been found to be fairly 

 etfective. 



All poisons should be labelled, and in their use care should 

 be taken that they are not placed within the reach of young 

 children. 



Diseases of Growing Tobacco. 



row- 



Mosaic Disease-— One of the most oimmon diseases of gn 

 ing tobacco is called "calico," or "mosaic" disease, because of the 

 mosaic-like appearance of the light and green portions of the leaf. 

 The disease causes the leaf to grow more rapidly near the veins 

 than elsewhere, and thus become wrinkled and corrugated. A 

 portion, or all of the plant, may lie affected. Slightly diseased 

 leaves are worthless as wrappers, and highly diseased leaves are of 

 no value for any purpose. For many years the nature of this 

 disease has been a mystery, and has been variously regarded as due 

 to a fungus, as the result" of an excess or deficiency of minerals in 



