Cross resistance, synergism and joint action of diflubenzuron with other insecticides and synergists on the black cutworm, Agrotis Ipsilon (Hfn.)‎ (Lepidoptera: Noctuidae)‎

Abstract EN

Z^ross resistances to pyriproxyfen (JHA), phenthoate (OP compound) and fenvalerate (pyrethroid) were measured in diflubenzuron resistant and susceptible strains of the black cutworm, Agrotis ipsilon (Hfn.).

No cross resistance to either phenthoate or fenvalerate was detected which might be due to distinct mode and site of action of chitin synthesis inhibitors and consequently distinct resistance mechanisms.

However, some cross resistance to pyriproxyfen was detected which might be due to the same resistance mechanism with diflubenzuron.

Piperonyl butoxide (a cytochrome P450 monooxygenase inhibitor) did not synergize diflubenzuron.

On the other hand, remarkable synergism resulted with triphenyl phosphate (TPP, a carboxylesterase inhibitor) and this synergism was recognized only in the diflubenzuron resistant strain and not in the susceptible strain.

This indicates that carboxylesterase enzyme is involved in diflubenzuron resistance in this insect pest.

In joint action studies, only pyriproxyfen showed some potentiation when mixed with diflubenzuron but phenthoate or fenvalerate did not show any.