In preliminary tests against the tobacco budworm (Heliothis virescens) and the tobacco hornworm (Protoparce sexta), nematode DD-136 and its associated bacterium gave promising results when the foliage was kept moist. The spore-forming bacteria DD-133-2 and DD-133-6 also were promising. A polyhedrosis virus was effective against the budworm but not against the hornworm. The fungus Spicaria rileyii was not effective against either insect.