Substituted 1-arylpyrazoles and their use as pesticides

1-arylpyrazoles derivatives of the general formula (I) wherein R1 is hydrogen, cyano, alkyl (with 1 to 4 carbon atoms), methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, trifluoromethyl, bromomethyl and cyanomethyl, R2 is 2, 2 , 2-trifluoroethyl, R 3 represents amino or represents the following grouping in which R5 is hydrogen or alkyl (with 1 to 4 carbon atoms), and R 6 represents phenyl, Ar is phenyl substituted two or three times by identical or different forms, being in position 2 fluorine or chlorine, in 4 position trifluoromethyl and in the 6-position fluorine, chlorine, cyano, methoxy, methylthio, trifluoromethyl, trifluoromethoxy, trifluoromethylthio, or Ar is a radical 2-pyridyl, which is substituted in position 5 and trifluoromethyl at position 3 fluorine or chlorine and