Field Studies of Selected Pathogens for the Control of the Corn Earworm, Heliothis Zea Boddie

Tests conducted at the University of Tennessee were designed to compare the control results of the corn earworm by three different pathogens and a standard chemical insecticide. Also, some methods of application were tested. The pathogens tested were a bacterium, Bacillus thuringiensis Berliner, a nuclear polyhedrosis virus specific for Heliothis zea, and the nematode, DD-136.

The treatments were applied under field conditions directly to the ears of corn.

The results indicated that general effectiveness is based on how accessible the pathogens are to the earworm larvae. Best control was accomplished by a treatment using a virus-nematode combination. That treatment and another using the bacillus gave better control results than a standard chemical insecticide.