Pesticidal cyclopropyl 2,4-dieneamides

A compound of the formula (III):

• ##STR11## or a salt thereof, wherein Q.sup.a is a phenyl or pyridyl group;
• X.sup.1a is hydrogen, fluoro or chloro;
• R.sup.2a, R.sup.3a, R.sup.4a and R.sup.5a are the same or different with at least one being hydrogen and the others being independently selected from hydrogen, halo, C.sub.1-4 alkyl or C.sub.1-4 haloalkyl;
• X.sup.1a is oxygen or sulphur;
• and R.sup.1a is selected from hydrogen, C.sub.1-6 hydrocarbyl and C.sub.1-6 hydrocarbyl substituted by dioxalanyl, halo, cyano, trifluoromethyl, trifluoromethylthio or C.sub.1-6 alkoxy.

A compound selected from:

• (-)-(2E,4E)-N-(2-Methylprop-2-enyl)5-[(1R,2S)-c-2-(3,4-dibromophenyl)-r-1-f luorocyclopropyl]-3-methylpenta-2,4-dienamide
• (-)-(2E/Z,4E)-N-(2-Methylprop-2-enyl)-5-]1R,2S)-c-2-(3,4-dibromophenyl)-r-1 -fluorocyclopropyl]-3-methylpenta-2,4-dienamide
• (+)-(2E,4E)-N-(2-Methylprop-2-enyl)-5-[(1S,2R)-c-2-(3,4-dibromophenyl)-r-1- fluorocyclopropyl]-3-methylpenta-2,4-dienamide
• (+)-(2E/Z,4E)-N-(2-Methylprop-2-enyl)-5-[(1S,2R)-c-2-(3,4,-dibromophenyl)-r -1-fluorocyclopropyl]-3-methylpenta-2,4-dienamide
• (+)-(2E,4E)-N-Isobutyl-5-[(1S,2R)-c-(3,4-dichlorophenyl)-r-1-chlorocyclopro pyl]-3-methylpenta-2,4-dienamide
• (-)-(2E,4E)-N-Isobutyl-5-[(1R,2S)-c-(3,4-dichlorophenyl)-r-1-chlorocyclopro pyl]-3-methylpenta-2,4-dienamide
• (-)-(2E,4E)-N-(S-1-Methylpropyl)-5-[(1R,2S)-c-(3,4-dichlorophenyl))-r-1-chl orocyclopropyl]-3-methylpenta-2,4-dienamide (-)-(2E,4E)-N-(R-1-Methylpropyl)-5-[(1R,2S)-c-(3,4--dichlorophenyl)-r-1-)c hlorocyclopropyl]-3-methylpenta-2,4-dienamide
• (-)-(2E/Z,4E)-N-Isobutyl-5-[(1S,2R)-trans-2-(3,4-dibromophenyl)cyclopropyl] -3-methylpenta-2,4-dienamide
• (+)-(2E/Z,4E)-N-Isobutyl-5-[(1R,2S)-trans-2-(3,4-dibromophenyl)cyclopropyl- 3-methylpenta-2,4-dienamide