1,4,diaryl-2-fluoro-2-butene insecticidal and acaricidal agents

A compound having the structural formula ##STR53## wherein Ar is phenyl optionally substituted with any combination of from one to three halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy or C.sub.1 -C.sub.4 haloalkoxy groups,

• 1- or 2-naphthyl optionally substituted with any combination of from one to three halogen, or C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy or C.sub.1 -C.sub.4 haloalkoxy groups,
• R and R.sub.1 are each independently C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.3 -C.sub.6 cycloalkyl or C.sub.3 -C.sub.6 halocycloalkyl, or R and R.sub.1 taken together with the carbon atom to which they are attached form a C.sub.3 -C.sub.6 cycloalkyl ring optionally substituted with any combination of from one to three halogen or C.sub.1 -C.sub.4 alkyl groups;
• and
• Z is cyano, CHO, CH.sub.2 OH or CH.sub.2 Br, and
• the optical isomers thereof, and
• the cis and trans isomers thereof.