The present invention relates to compounds of formula (I): Wherein A1, A2, A3, A4, G1, L, Y1, Y2, Y3, Y4, R1, R2, R3 and R4 are as defined in claim 1; or a salt or N-oxide thereof. Furthermore, the present invention relates 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.