Insecticidal [1,1'-biphenyl]-3-ylmethyl esters

A compound of the formula ##STR6## wherein (1) b is 0, a is 3 or 4, and R is selected from 2,2,3,3-tetramethylcyclopropyl, 2,2-dichloro-3,3-dimethylcyclopropyl, 3-cyclopentylidenemethyl-2,2-dimethylcyclopropyl, 3-(2-methyl-1-propenyl)-2,2-dimethylcyclopropyl, and 3-(1,2-dibromo-2,2-dichloroethyl)-2,2-dimethylcyclopropyl, and when a is 3,

• A is fluoro, or A is 2-chloro, 2-bromo, 2-methyl, or 2-ethyl with two additional fluoro groups, or A is 2- and 4-substituents independently selected from fluoro, chloro and methyl with one additional fluoro group, and
• when a is 4,
• A is fluoro, or A is 2- and 4-substituents independently selected from fluoro, chloro and methyl with two additional fluoro groups;
• or
• R is selected from 3-[(2-chloro-2-phenyl)ethenyl]-2,2-dimethylcyclopropyl, 1-(4-chlorophenyl)-2-methylpropyl, 2,2-dichloro-1-(4-ethoxyphenyl)cyclopropyl, and 1-(2-chloro-4-trifluoromethylphenylamino)-2-methylpropyl, a is 3 or 4, and A is fluoro;
• or
• (2) a is 3 or 4, b is 4, R is selected from 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropyl and 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropyl, and
• A is fluoro or a 2-substituent selected from chloro, bromo, and lower alkyl with 2 or 3 fluoro groups, and B is fluoro or a 2'-substituent selected from chloro and methyl with 3 fluoro groups.