| Third-instar tobacco budworms, Heliothis, susceptible or resistant to pyrethroids were tested by exposure to residues of insecticides in glass liquid scintilillation vials. These biossays were done to find alternative insecticides or insecticide combinations for control of larvae resistant to pyrethroids, to evaluate the effect of synergists on insecticide toxicity and resistance, and to establish the main mechanisms of resistance present. Insecticides effective for control of resistant third-instar tobacco budworms included profenofos, sulprofos, acephate, endusulfan, methomyl, and thiodicarb. Cypermethrin combined with chlordimeform, piperonyl butoxide nor chlordimeform produced more thenfive-fold synergism. The only synergistic insecticide combination... |
