4. To assist in the prediction of insect outbreaks and the timing of insecticidal 

 applications. 



5. To assist in the detection of introduced insect pests. 



6. To control insects in areas where other types of control cannot or should not be 

 used. 



7. To keep insects away from porches, yards, drive-in type of food establishments, 

 and other outdoor areas. 



8. To assist in the evaluation of results of other types of insect control. 



Some of the advantages of the use of light traps are: (1) They leave no poisonous 

 residues on crops. (2) They operate continuously, thereby eliminating the necessity 

 of timing the application of the control measure used. (3) They operate when fields are 

 wet as well as when dry. (4) The cost of operation is low- -about 30 to 40 cents a month 

 for one 15- watt lamp. 



Results of Experiments to Protect Tobacco from Tobacco 

 and Tomato Hornworms 3 



Experiments were conducted in six fields of tobacco in southern Indiana during the 

 seasons of 1956-59. During 1959 the traps were operated by the farmers but the records 

 were taken by the project personnel. Results of preliminary experiments in 1954 and 

 1955 indicated that a trap equipped with one 15-watt BL lamp would protect the tobacco 

 within a radius of 100 to 120 feet from the lamp. The number of lamps used per field 

 varied with the size and shape of the field. No insecticides were used in the treated fields 

 and hand picking of worms was not practiced. Check fields were selected which were 

 near the lighted ones (20 to 60 rods distance) and in which the tobacco had been planted 

 at the same time as in the experimental fields. In all the check fields the growers prac- 

 ticed hand picking of the worms once or twice a week and insecticides were applied one 

 or two times in certain of the years to some of the check fields. The use of insecticide, 

 mostly because of poor application and timing, seemed to have little effect on the horn- 

 worm population and resulting damage. 



The results for the 4 years' experiments are given in the following table: 



Tobacco and Tomato Hornworm Damage to Tobacco 

 Jefferson County, Indiana 



Year 



Lighted fields 



Plants infested 



Leaves destroyed 



Unlighted fields 



Plants infested 



Leaves destroyed 





ret. 



1956 



7.9 



1957 



11.8 



1958 



7.0 



1959* 



16.6 



Pet. 

 0.14 



.20 



.14 



.19 



Pet. 

 36.0 



73.8 



25.2 



28.2 



Pet. 



0.76 



1.06 



.55 



.60 



*Farmer operated 



Tobacco is harvested in southern Indiana from about August 20 to September 5. This 

 early harvest accounts in part for the small amount of damage caused by the hornworms. 



3 Data for most parr unpublished. 



51 



