Treatment of Other Insects 

 Occurring With Hornworms 



Hornworm infestations are sometimes accom- 

 panied by infestations of aphids or budworms. 

 The TDE treatment will also control budworms. 

 If the aphid infestation is severe, however, it may 

 be necessary to apply parathion. The two insecti- 

 cides may be used in one treatment. A dust con- 

 taining 1 percent of parathion and 10 percent of 

 TDE may be purchased for this purpose. Do not 

 attempt to mix your own parathion dust (see 

 Precautions on p. 6) . If you use a spray, add 1 

 pound of 15-percent parathion wettable powder 

 to the quantity of TDE spray to be applied per 

 acre. 



Do not include parathion in the hornworm 

 treatment unless an examination of the plants 

 shows that the aphids are numerous. In addition 

 to the personal hazards to the operator, unneces- 

 sary applications of parathion may destroy many 

 natural enemies of both hornworms and aphids. 

 Furthermore, special precautions must be fol- 

 lowed in using parathion (see p. 6j. 



Some Insecticides Reduce 

 Value of Tobacco 



Certain insecticides that are effective against 

 hornworms cannot be recommended, because their 

 use may lower the value of the tobacco crop. 

 Growers who apply these materials risk having 

 their crop down-graded on the market, or even 

 rejected, because of disagreeable odor or the pres- 

 ence of undesirable residues. BHC and toxaphene 

 have been found to impart disagreeable odors to 

 the cured tobacco, and may seriously impair the 

 flavor and aroma of cigarettes. There are indi- 

 cations that lindane may also impair the flavor 

 of the cured tobacco. Lead arsenate leaves resi- 

 dues of two poisons, lead and arsenic. Paris 

 green also leaves residues of arsenic, and under 

 some conditions may cause plant injury. 



From the evidence now available of insecticides 

 that will control hornworms on tobacco, TDE pre- 

 sents the least hazard to dust formulators, persons 

 applying the insecticide, crop handlers, and 

 smokers. It has not been found to impair the 

 smoking quality of the cured tobacco. However, 

 to avoid excessive quantities on the tobacco, it 



