Synergistic tickicidal compositions containing organophosphorus compounds and cyclopropane carboxylates

A composition of matter comprising as a tickicidally effective active ingredient a mixture comprising as a first component a compound selected from the group consisting of (a) (.+-.)-.alpha.-cyano-3-phenoxybenzyl (.+-.)-cis/trans-3-(2-chloro-3,3,3-trifluoro-prop-1-en-1-yl)-2,2-dimethylc yclopropane carboxylate (CPC-I) and (b) (.+-.)-.alpha.-cyano-3-phenoxybenzyl (.+-.)-cis-3-(2-chloro-3,3,3-trifluor oprop-1-en-1-yl)-2,2-dimethylcyclopropane carboxylate (CPC-II);

• and as a second component at least one insecticidal organophosphorus compound selected from the group consisting of cis/trans 2-chloro-1-(2,4-dichlorophenyl)-vinyl diethyl phosphate, O-(4-bromo-2,5-dichlorophenyl) O,O-diethyl phosphorothioate (bromophos-ethyl), O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate, and O,O,O',O'-tetraethyl-S,S'-methylene di(phosphorodithioate) (ethion), and wherein the weight ratio of the said first component to the said second component is in the range from 1:2 to 4:1 when the first component is CPC II and the second component is bromophos-ethyl or ethion and the said weight ratio is 1:2 for the remaining combinations.