228 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



given off by the glandular hairs of the tobacco, and if there be fre- 

 quent rains, this is washed off and the insects develop unimpeded. 

 The bugs are found in late fall until frost, but the exact number of 

 generations has not been determined. They evidently hibernate 

 in or near the tobacco field. 



Control. Professor A. L. Quaintance, who experimented with 

 remedies in Florida, has found, curiously enough, that the best 

 insecticide against this pest is its own food, tobacco. A solution 

 of concentrated nicotine, diluted with sixty parts of water, was 

 found very effective when sprayed upon the bugs. It should be 

 applied with a bent-necked nozzle which will throw a fine spray 

 upon both surfaces of the leaves, as most of the young are on the 

 lower surface. Home-made tobacco decoction (page 55) was 

 also used, but did not prove as satisfactory. The spraying should 

 be done early in the day, when the adult bugs are sluggish and do 

 not fly readily. Infested areas should be sprayed when the 

 pest first makes its appearance so as to prevent multiplication 

 and spread. Thorough cleaning up of rubbish and destruction of 

 the old stalks in the fall will be of service against this as well as 

 other tobacco pests. A few plants set early in the spring would 

 probably attract the hibernating bugs as they emerge, so that 

 they might be readily killed upon them. 



The Hornworms or Tobacco-worms * 



Of all the insects feeding upon tobacco, the Hornworms are 

 the most widely injurious and therefore best known. The cater- 

 pillars of two species of moths are commonly included under thi s 

 popular name, both species occurring throughout the tobacco- 

 growing States, the northern tobacco- worm being more common 

 in the North and the southern tobacco-worm more common in the 

 South. The differences in the adult moths may be readily appre- 

 ciated from Figs. 162 and 1^63, the southern form being darker and 

 with brighter orange spots on the abdomen, and the white lines on 



* Phlegethontius quinquemaculata Haworth (Northern), and P. sexfa 

 Johanssen (Southern). Family Sphingida. 



