The present invention relates to compounds of formula (I) wherein A1, A2, A3, A4, R1, R2, R3, R4 and n are as defined in claim 1; or a tautomer, isomer, enantiomer, salt or N-oxide thereof; to intermediates for preparing compounds of formula (I), to compositions comprising them and to methods of using them to combat and control insect, acarine, nematode and mollusc pests.