NOVELTY - Substituted isoxazoline compounds (I) and their geometric- and stereoisomers, N-oxides and salts are new.    USE - (I) are useful for controlling parasites in and on warm-blooded animals (claimed), where the parasites are ectoparasites, especially insects, acari (mites and ticks), and crustaceans (sea lice), and endoparasites. (I) are useful against: hygiene pests; plant nematodes; all stages of development of sucking insects and eating insects on crops e.g. cereal cotton, rice, maize, soya, potatoes, vegetables, fruit, tobacco, hops, citrus and avocados; and helminths. (I) are useful as a soil insecticide against pests in the soil, and for protecting animal, especially productive livestock, domestic animal and pets, against parasitic helminthes and parasitic pests. The ability of (I) to control parasites was tested against Rhinophis sanguineus on Mongolian gerbils. The result showed that 5-(4-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl)-3-methyl-thiophene-2-carboxylic acid (4-trifluoromethyl-thiazol-2-yl)-amide exhibited 100% killing efficacy at 32 mg/kg.    ADVANTAGE - (I) are less costly, less toxic, environmentally safe and have different modes of action.    DETAILED DESCRIPTION - Substituted isoxazoline compounds of formula (I) and their all geometric- and stereoisomers, N-oxides and salts are new.    X = S(O)m, O or NR5a;    X1, X2 = CR3a or N;    n = 0-4;    m = 0-2;    B1-B3 = CR2a or N;    R2a = H or R2;    R3a = H or R3;    R1 = 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl, 3-6C cycloalkyl, 4-7C alkylcycloalkyl or 4-7C cycloalkylalkyl (all optionally substituted with one or more substituents of R4);    R4 = halo, 1-6C alkyl, 1-6C alkoxy, 1-6C alkylthio, 1-6C alkylsulfinyl, 1-6C alkyl-sulfonyl, CN or nitro;    R2 = halo, 1-6C alkyl, 1-6C haloalkyl, 1-6C alkoxy, 1-6C haloalkoxy, 1-6C alkylthio, 1-6C haloalkylthio, 1-6C alkylsulfinyl, 1-6C haloalkylsulfinyl, 1-6C alkylsulfonyl, 1-6C haloalkylsulfonyl, N-mono- or N,N-di-1-6C alkylamino, 1-6C alkoxycarbonyl, CN or NO2;    R3 = phenyl, pyridyl or pyrimidyl (all optionally substituted with halo, 1-6C alkyl, 1-6C haloalkyl, 1-6C alkoxy, 1-6C haloalkoxy, amino, CN or nitro), H, halo, 1-6C alkyl, 1-6C haloalkyl, 3-6C cycloalkyl, 3-6C halocycloalkyl, 1-6C alkoxy, 1-6C haloalkoxy, 1-6C alkylthio, 1-6C haloalkylthio, 1-6C alkyl-sulfinyl, 1-6C haloalkylsulfinyl, 1-6C alkylsulfonyl, 1-6C haloalkylsulfonyl, amino, N-mono- or N,N-di-1-6C-alkylamino, 1-6C alkoxycarbonyl, cyano or nitro;    Z = halo, Q or -C(W1)-NR5R6;    Q = 5- or 8-membered heterocyclic ring or 6-10C carbocyclic ring system or 8-, 9- or 10-membered fused hetero-bicyclic ring system (all optionally substituted with one or more substituents of halo, 1-6C alkyl, 1-6C haloalkyl, 3-6C cycloalkyl, 3-6C halocycloalkyl, 1-6C alkoxy, 1-6C haloalkoxy, 1-6C alkylthio, 1-6C haloalkylthio, 1-6C alkyl-sulfinyl, 1-6C haloalkylsulfinyl, 1-6C alkylsulfonyl, 1-6C haloalkylsulfonyl, amino, N-mono- or N,N-di-1-4C-alkylamino, 1-6C alkoxycarbonyl, cyano, nitro, sulfonamido, N-mono- or N,N-di-1-4C alkylsulfonamido, 1-6C alkylcarbonylamino, N-mono- or N,N-di-1-6C-alkylaminocarbonyl, 2-6C alkanoyl, -(alk)-C(W1a)NR5bR7, phenyl, benzyl, benzoyl, phenoxy, pyridyl, pyridyl-(alk)-, pyrimidyl or pyrimidyl-(alk)-, where the phenyl, benzyl, benzoyl, phenoxy, pyridyl and pyrimidyl are optionally substituted with halo, 1-6C alkyl, 1-6C haloalkyl, 1-6C alkoxy, 1-6C haloalkoxy, CN, nitro or amino);    W1, W1a = O or S; either    R5, R5a, R5b = H, 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl, 3-6C cycloalkyl, 4-7C alkylcycloalkyl, 4-7C cycloalkylalkyl, 1-6C alkylcarbonyl or 1-6C alkoxycarbonyl; and    R6 = 2-6C alkenyl, 1-6C alkyl, 2-6C alkynyl, 3-6C cycloalkyl, 4-7C alkylcycloalkyl or 4-7C cycloalkylalkyl (all optionally substituted with halo, 1-6C alkoxy, 1-6C alkylthio, 1-6C alkyl-sulfinyl, 1-6C alkylsulfonyl, CN, NO2, amino, N-mono- or N,N-di-1-4C-alkylamino, 3-6C cycloalkylamino, 1-6C alkoxycarbonyl, 2-6C alkanoyl, 1-6C alkylcarbonylamino, aminocarbonyl, N-mono- or N,N-di-1-6C-alkylaminocarbonyl, -C(W1a)NR5bR7 or Q1b), H or Q1a; or    NR5R6 = 3- to 7-membered ring which optionally contains a further heteroatom of N, S or O and which ring is further optionally substituted by 1-2C alkyl, 1-2C alkoxy, halo, cyano or nitro;    Q1a, Q1b = Q; and    R7 = 1-6C alkyl, 2-6C alkenyl, 2-6C akynyl 3-6C cycloalkyl, 4-7C alkylcycloalkyl or 4-7C cycloalkylalkyl (all optionally substituted with pyridyl, pyrimidyl or thiazolyl (all mono- or disubstituted by halo, CN, 1-2C alkyl or 1-2C haloalkyl), halo, 1-6C alkoxy, 1-6C alkylthio, 1-6C alkylsulfinyl, 1-6C alkylsulfonyl, CN, NO2, amino or N-mono- or N,N-di-1-6C alkylamino).    An INDEPENDENT CLAIM is included for a composition comprising at least one compound (I), in addition to a carrier and/or a dispersant.