A compound of formula (1): wherein X is O or S; n is 0 or 1; Y is O, S or NR.sup.7 ; R.sup.1 is hydrogen, halogen, C.sub.1-6 alkyl, C.sub.1-6 haloalkyl, C.sub.1-6 alkoxy, C.sub.1-6 haloalkoxy, C.sub.1-6 alkylthio, C.sub.1-6 haloalkylthio, C.sub.3-6 cycloalkyl, C.sub.1-6 alkoxy(C.sub.1-6)alkyl or SF.sub.5 ; R.sup.2 is hydrogen, halogen, C.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 haloalkoxy, C.sub.1-6 alkylthio, C.sub.1-6 haloalkylthio, C.sub.1-6 alkylsulfinyl, C.sub.1-6 haloalkylsulfinyl, C.sub.1-6 alkylsulfonyl, C.sub.1-6 haloalkylsulfonyl, C.sub.1-6 haloalkyl, cyano, nitro, CHO, CH.dbd.NOR.sup.5, C.sub.1-6 alkylcarbonyl, C.sub.1-6 alkoxycarbonyl or SF.sub.5 ; or together R.sup.1 and R.sup.2 form a five or six membered saturated or unsaturated carbocyclic ring, optionally substituted by one or two C.sub.1-6 alky groups; R.sup.3, is hydrogen, C.sub.1-6 alkyl, CH.sub.2 (C.sub.1-4 haloalkyl), C.sub.1-6 cyanoalkyl, C.sub.3-6 alkenyl, C.sub.3-6 alkynyl, C.sub.1-6 -alkoxy(C.sub.1-6)alkyl, C.sub.1-6 alkylthio(C.sub.1-6)alkyl, C.sub.1-6 alkoxy(C.sub.1-6)alkoxy(C.sub.1-6)alkyl, C.sub.1-6 alkylcarbonyl, C.sub.1-6 alkoxycarbonyl, formyl, C.sub.1-6 alkylcarbonyl(C.sub.1-6)alkyl, C.sub.1-6 alkoxycarbonyl(C.sub.1-6)alkyl, C.sub.1-6 alkylaminocarbonyl, di(C.sub.1-6)alkylaminocarbonyl, optionally substituted phenoxycarbonyl, optionally substituted phenyl(C.sub.1-4)alkyl or S(O).sub.q R.sup.6 ; R.sup.4 is hydrogen, halogen, cyano, C.sub.1-8 alkyl, C.sub.1-6 haloalkyl, C.sub.1-6 cyanoalkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, C.sub.3-7 cycloalkyl, C.sub.3-7 halocycloalkl, C.sub.3-7 cyanocycloalkyl, C.sub.1-3 alkyl(C.sub.3-7)cycloalkyl, C.sub.1-3 alkyl(C.sub.3-7)halocycloalkyl, C.sub.3-6 cycloalkyl(C.sub.1-6)alkyl, C.sub.5-6 cycloalkenyl, C.sub.5-6 cycloalkenyl(C.sub.1-6)alkyl, C.sub.2-6 haloalkenyl, C.sub.1-6 cyanoalkenyl, C.sub.1-6 alkoxy(C.sub.1-6)alkyl, formyl, C.sub.1-6 carboxyalkyl, C.sub.1-6 alkylcarbonyl(C.sub.1-6)alkyl, C.sub.1-6 alkoxycarbonyl(C.sub.1-6)alkyl, C.sub.1-6 alkylthio(C.sub.1-6)alkyl, C.sub.1-6 alkylsulfinyl(C.sub.1-6)alkyl, C.sub.1-6 alkylsulfonyl(C.sub.1-6 alkyl, aminocarbonyl(C.sub.1-6)alkyl, C.sub.1-6 alkylaminocarbonyl(C.sub.1-6)alkyl, di(C.sub.1-6)alkylaminocarbonyl(C.sub.1-6)alkyl, C.sub.1-6 alkoxycarbonyl, C.sub.1-6 alkylcarbonyl, aminocarbonyl, C.sub.1-6 alkylaminocarbonyl, di(C.sub.1-6)alkylaminocarbonyl, optionally substituted phenyl, optionally substituted phenyl(C.sub.1-4)alkyl, optionally substituted phenyl(C.sub.2-4)alkenyl, optionally substituted heteroaryl, optionally substituted heteroaryl(C.sub.1-4)alkyl, optionally substituted heterocyclyl, optionally substituted heterocyclyl(C.sub.1-4)alkyl, a group OR.sup.8, a group SH, a group S(O).sub.p R.sup.9, a group NR.sup.10 R.sup.11 or a group C(R.sup.12).dbd.NOR.sup.13 ; R.sup.5 is hydrogen, C.sub.1-6 alkyl, optionally substituted phenyl or optionally substituted phenyl(C.sub.1-4)alkyl; R.sup.6 is C.sub.1-6 alkyl, C.sub.1-6 haloalkyl or optionally substituted phenyl; R.sup.7 is hydrogen, cyano, C.sub.1-8 alkyl, C.sub.1-6 haloalkyl, C.sub.1-6 cyanoalkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, C.sub.3-7 cycloalkyl, C.sub.2-6 haloalkenyl, C.sub.3-6 cycloalkyl(C.sub.1-6)alkyl, C.sub.1-6 alkoxy(C.sub.1-6)alkyl, C.sub.1-6 alkoxycarbonyl, C.sub.1-6 alkylcarbonyl, C.sub.1-6 alkylaminocarbonyl, di(C.sub.1-6)alkylaminocarbonyl, optionally substituted phenyl or optionally substituted heteroaryl; R.sup.8 is hydrogen, C.sub.1-6 alkyl, C.sub.1-6 haloalkyl, C.sub.3-6 alkenyl, C.sub.1-4 cyanoalkyl, C.sub.1-6 alkoxycarbonyl(C.sub.1-6)alkyl, optionally substituted phenyl, optionally substituted phenyl(C.sub.1-4)alkyl, optionally substituted heteroaryl, N.dbd.C(CH.sub.3).sub.2 ; R.sup.9 is C.sub.1-6 alkyl, C.sub.1-6 haloalkyl, C.sub.3-6 alkenyl, cyano, C.sub.1-4 cyanoalkyl, C.sub.1-6 alkoxycarbonyl(C.sub.1-6)alkyl, optionally substituted phenyl, optionally substituted phenyl(C.sub.1-4)alkyl or optionally substituted heteroaryl; R.sup.10 and R.sup.11 are, independently, hydrogen, C.sub.1-8 alkyl, C.sub.3-7, cycloalkyl, C.sub.3-6 alkenyl, C.sub.3-6 alkynyl, C.sub.2-6 haloalkyl, C.sub.1-6 alkoxy(C.sub.1-6)alkyl, C.sub.1-6 alkoxycarbonyl, optionally substituted phenoxycarbonyl, formyl, C.sub.1-6 alkylcarbonyl, C.sub.1-6 alkylSO.sub.2, optionally substituted phenylSO.sub.2 or optionally substituted phenyl(C.sub.1-4)alkyl; R.sup.12 is C.sub.1-3 alkyl R.sup.13 is C.sub.1-6 alkyl, optionally substituted phenyl(C.sub.1-2)alkyl; and p and q are, independently, 0, 1 or 2, processes for preparing these compounds, compositions comprising them, methods of using them to combat fungal diseases and methods of using them to combat or control insect, acarine, mollusc and nematode pests.