A bis-organo sulfur compound of formula: or a veterinarily or agriculturally acceptable salt thereof, wherein: m = 0, 1, 2; n = 0, 1, 2; p 1, 2 or 3; q = 0, 1, 2, 3 or 4; R 1 is haloalkyl, haloalkenyl, haloalkynyl; or aryl, aralkyl, heteroaryl, or heterocyclyl each of which is substituted by one or more halogen atoms; all of which may be further substituted by one or more R 10; R 2 is halogen, cyano, alkyl, haloalkyl, or -C= -R 9; R 3 is hydrogen, halogen, alkyl or haloalkyl; R 4 is haloalkyl, haloalkenyl, haloalkynyl, or aralkyl, which is substituted by one or more halogen atoms; all of which may be further substituted by one or more R 10, or R 4 is aryl or a 3- to 7-membered saturated or partially unsaturated heterocyclic ring which may contain 1 to 3 heteroatoms selected from oxygen, sulfur and nitrogen or a 5- to 6-membered heteroaromatic ring which may contain 1 to 3 heteroatoms selected from oxygen, nitrogen and sulfur, wherein aryl, the heterocyclic ring, or the heteroaromatic ring may be fused to another aryl ring or a 5- to 6-membered saturated, partially unsaturated or aromatic heterocyclic ring which may contain 1 to 3 heteroatoms selected from oxygen, nitrogen and sulphur; and wherein the aryl, heteroaryl or heterocyclic rings or the respective fused ring systems may be unsubstituted or substituted by any combination of 1 to 6 R 10 groups; R 5, R 6, R 7 and R 8 are independently from each other hydrogen, halogen, alkyl, or haloalkyl; R 9 is alkyl, hydroxy, amino, alkoxy, aryloxy, alkylamino, or dialkylamino, the latter four optionally substituted with halogen; G is Oxygen or Sulfur; and R 10 = halogen, cyano, nitro, hydroxy, mercapto, amino, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, haloalkyl, haloalkenyl, haloalkynyl, halocycloalkyl, halocycloalkenyl, alkoxy, alkenyloxy, alkynyloxy, haloalkoxy, haloalkenyloxy, haloalkynyloxy, cycloalkoxy, cycloalkenyloxy, halocycloalkoxy, halocycloalkenyloxy, alkylthio, haloalkylthio, cycloalkylthio, halocycloalkylthio, alkylsulfinyl, alkenylsulfinyl, alkynyl-sulfinyl, haloalkylsulfinyl, haloalkenylsulfinyl, haloalkynylsulfinyl, alkylsulfonyl, alkenylsulfonyl, alkynylsulfbnyl, haloalkyl-sulfonyl, haloalkenylsulfonyl, haloalkynylsulfonyl, alkylamino, alkenylamino, alkynylamino, di(alkyl)amino, di(alkenyl)-amino, di(alkynyl)amino, or trialkylsilyl; with the proviso that at least one group from R 2, R 3, R 4, R 5 and R 6 is not hydrogen, alkyl or haloalkyl.. m = 0, 1, 2; n = 0, 1, 2; p 1, 2 or 3; q = 0, 1, 2, 3 or 4; R 1 is haloalkyl, haloalkenyl, haloalkynyl; or aryl, aralkyl, heteroaryl, or heterocyclyl each of which is substituted by one or more halogen atoms; all of which may be further substituted by one or more R 10; R 2 is halogen, cyano, alkyl, haloalkyl, or -C= -R 9; R 3 is hydrogen, halogen, alkyl or haloalkyl; R 4 is haloalkyl, haloalkenyl, haloalkynyl, or aralkyl, which is substituted by one or more halogen atoms; all of which may be further substituted by one or more R 10, or R 4 is aryl or a 3- to 7-membered saturated or partially unsaturated heterocyclic ring which may contain 1 to 3 heteroatoms selected from oxygen, sulfur and nitrogen or a 5- to 6-membered heteroaromatic ring which may contain 1 to 3 heteroatoms selected from oxygen, nitrogen and sulfur, wherein aryl, the heterocyclic ring, or the heteroaromatic ring may be fused to another aryl ring or a 5- to 6-membered saturated, partially unsaturated or aromatic heterocyclic ring which may contain 1 to 3 heteroatoms selected from oxygen, nitrogen and sulphur; and wherein the aryl, heteroaryl or heterocyclic rings or the respective fused ring systems may be unsubstituted or substituted by any combination of 1 to 6 R 10 groups; R 5, R 6, R 7 and R 8 are independently from each other hydrogen, halogen, alkyl, or haloalkyl; R 9 is alkyl, hydroxy, amino, alkoxy, aryloxy, alkylamino, or dialkylamino, the latter four optionally substituted with halogen; G is Oxygen or Sulfur; and R 10 = halogen, cyano, nitro, hydroxy, mercapto, amino, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, haloalkyl, haloalkenyl, haloalkynyl, halocycloalkyl, halocycloalkenyl, alkoxy, alkenyloxy, alkynyloxy, haloalkoxy, haloalkenyloxy, haloalkynyloxy, cycloalkoxy, cycloalkenyloxy, halocycloalkoxy, halocycloalkenyloxy, alkylthio, haloalkylthio, cycloalkylthio, halocycloalkylthio, alkylsulfinyl, alkenylsulfinyl, alkynyl-sulfinyl, haloalkylsulfinyl, haloalkenylsulfinyl, haloalkynylsulfinyl, alkylsulfonyl, alkenylsulfonyl, alkynylsulfbnyl, haloalkyl-sulfonyl, haloalkenylsulfonyl, haloalkynylsulfonyl, alkylamino, alkenylamino, alkynylamino, di(alkyl)amino, di(alkenyl)-amino, di(alkynyl)amino, or trialkylsilyl; with the proviso that at least one group from R 2, R 3, R 4, R 5 and R 6 is not hydrogen, alkyl or haloalkyl..