hatched larvae of the tobacco hornworm 



Pupa of the tobacc 



instead prefer to suck nectar from the flowers of 

 jimsonweed and tobacco. Their feeding causes 

 no damage to the plants. 



The insects pass the winter in the soil as 

 pupae. In May or June, moths emerge and 

 mate, and the females lay their eggs. 



Hornworms usually produce 1 to 4 generations 

 a season; the number depends on latitude and 

 weather. 



HOW TO CONTROL THEM 



You can control hornworms by following rec- 

 ommended cultural practices, by handpicking, 

 and by applying an insecticide to tobacco plants. 

 Cultural practices and handpicking greatly re- 

 duce the need for insecticides. 



Cultural Practices 



1. Immediately after harvest plow up or oth- 

 erwise destroy all stalks remaining in the field. 

 The suckers of these stalks furnish food for a 

 large number of hornworms. This practice cuts 

 down on insect breeding. 



2. Plow the field in the fall. This practice 

 kills overwintering pupae. The field may be 

 seeded to rye or some other suitable cover crop 

 after plowing. 



Handpicking 



The control of hornworms by handpicking is 

 profitable and should be done whenever prac- 

 ticable. 



hornworms on tobacco by 

 or TDE to infested plants. 



Insecticides 



You can control 

 applying endrin 



Either insecticide is available from dealers as 

 dust, ready for use, or as emulsifiable concen- 

 trates and wettable powders, which can be mixed 

 with water and applied as sprays. 



If you dust, apply li/o-percent endrin or 10- 

 percent TDE dust at the rate of 8 to 15 pounds 

 per acre for small plants, and 20 to 25 pounds 

 per acre for large plants. Apply with hand or 

 power equipment or by aircraft. If you use 

 aircraft, apply 25 to 30 pounds of dust per acre. 



If you spray, mix one of the recommended in- 

 secticides with water as follows : 



High-pressure ground sprayer: Use 1 to 2 

 pints of a 19.5-percent endrine emulsifiable con- 

 centrate, or 2 quarts of a 25-percent TDE emul- 

 sifiable concentrate, or 4 pounds of a 50-percent 

 TDE wettable powder with 75 to 100 gallons of 

 water per acre. Note: You will need about 75 

 gallons for small and medium-sized plants; 

 about 100 gallons for large plants. 



Low-pressure ground sprayer: Use same 

 quantity of endrin or TDE emulsifiable concen- 

 trate as recommended above with about 5 gallons 

 of water per acre. 



Aircraft spray equipment : Use same quantity 

 of endrin or TDE as recommended above with 2 

 to 5 gallons of water per acre, depending upon 

 the capacity of the equipment. 



If you plan to spray with a low-pressure 

 ground sprayer or with aircraft equipment, use 

 an emulsifiable concentrate; a wettable powder 

 may clog the nozzles of these sprayers and also 

 is difficult to keep well mixed with water. 



Examine tobacco fields for hornworms when 

 plants are about knee high (or smaller in late- 

 planted fields). Inspect plants carefully to de- 

 termine the extent of an infestation ; hornworms 

 blend in with the foliage and are often difficult 

 to detect. 



Make the first application of insecticide when 

 hornworms are too numerous to be controlled 

 easily by handpicking. If you dust, make sure 

 that there is little or no wind. For best results, 

 dust in early morning or late afternoon when the 

 air is more likely to be calm. 



