ENTOMOLOGY 253 



disking or plowing. Disking reaches only a small percentage of the 

 cells and increases the mortality to a very slight extent, but plowing 

 increases the mortality greatly. In plowing land it is necessary to 

 plow only to the usual depth, for very few larvaB will enter the 

 harder ground below to pupate. 



Paris green, dusted on tobacco by means of a dust gun is in 

 common use in Kentucky and Tennessee with very good results. 

 Burning of the plant often occurs from the use of Paris green. This 

 is usually, though not always, due to a failure to make an even ap- 

 plication. From 1 to 2 pounds per acre are applied, without a dilu- 

 ent or carrier. It was found that l 1 /^ pounds per acre, if carefully 

 applied when there is very little or no breeze, is an effective remedy 

 against all except the largest worms. The nearly full-grown worms 

 should be hand-picked or they will do considerable injury before 

 they succumb to the poison, if, indeed, they do succumb. 



An insecticide has been found in powdered arsenate of lead 

 that will not burn the foliage. This poison is, however, more costly 

 than Paris green, for from 4 to 5 pounds should be applied per acre, 

 at a cost of 80 cents to $1. Arsenate of lead must be mixed with a 

 carrier. The writer finds that sifted ashes is the most satisfactory. 

 Finely sifted air-slaked lime was tried, but did not dust evenly. 

 An even, thorough application is absolutely necessary for good 

 resufts. Only the arsenates of lead that are especially prepared for 

 use upon tobacco should be used, for brands not thus prepared have 

 been found to be too slow in their insecticidal action. 



The Budworms. In the shade-tobacco districts of Georgia 

 and Florida the bud worms are more injurious than the horn worms 

 and are more costly to combat. The eggs are deposited in the tips 

 or buds of the plant, and a single larva may eat through several 

 leaves, rendering them unfit for wrappers and thereby greatly reduc- 

 ing their value. 



Shade-tobacco growers in Georgia and Florida have to poison 

 twice a week for the budworms during the growing season. The 

 usual insecticide is Paris green at the rate of 1 tablespoon ful to a 

 peck of sifted corn meal. This mixture is sifted into the bud. Ac- 

 cording to W. A. Hooker, the annual cost of treating the budworms 

 for labor and supplies averages from $12 to $15 per acre. 



The Tobaeco Splitworm. The cosmopolitan tobacco splitworm 

 was first reported from tobacco in this country by Prof. Gerald 

 McCarthy. In 1898 Prof. A. L. Quaintance stated that the larvae 

 usually made their appearance about the last of May at Lake City, 

 Florida; that the life cycle was found to be not more than twenty 

 days ; that the Iarva3 are miners, living between the upper and lower 

 epidermis of the leaves, and that by their work they render tho 

 leaves worthless for wrappers. They have the habit of leaving their 

 mines and crawling over the surface of the leaf to mine in another 

 place. This habit led Professor Quaintance to suggest an arsenical 

 spray. According to him the winter may be passed cither as Iarvu3 

 or pupae in rubbish upon the surface of the ground. It therefore 



