Microencapsulated aerosol insecticides

An insecticidal composition in the form of an aerosol water-in-oil emulsion comprising:

• (a) an amount of an aqueous suspension of microencapsulated pyrethroid insecticide to give an insecticide concentration in the composition of from 0.001 to 5% w/w;
• (b) one or more solvents in an amount of from 1 to 20% w/w and selected from the group consisting of liquid n-paraffins, liquid isoparaffins, cycloalkanes, naphthene-containing solvents, white spirit, kerosene, ester solvents, silicone solvents or oils, fatty acids, dialkyl phthalates, C.sub.5 -C.sub.11 alcohols and fatty alcohols;
• (c) one or more emulsifiers in an amount of from 0.5 to 8% w/w and selected from the group consisting of mono-, di- and tri-sorbitan esters, polyoxyethylene sorbitan esters, mono- and poly-glycerol esters, ethoxylated nonionic emulsifiers, propoxylated nonionic emulsifiers and ethoxylated/propoxylated nonionic emulsifiers;
• (d) from 2 to 80% w/w of one or more propellants;
• (e) from 0 to 5% w/w of one or more oil phase soluble insecticides;
• and
• (f) water sufficient to bring the total composition to 100% w/w,
• the composition having an HLB requirement of 4 to 7.

A method of killing insects that contact a synthetic polymeric surface comprising applying to the surface an insecticidal composition in the form of an aerosol water-in-oil emulsion, said composition comprising:

• (a) an amount of an aqueous suspension of microencapsulated pyrethroid insecticide to give an insecticide concentration in the composition of from 0.001 to 5% w/w;
• (b) one or more solvents in an amount of from 1 to 20% w/w and selected from the group consisting of liquid n-paraffins, liquid isoparaffins, cycloalkanes, naphthene-containing solvents, white spirit, kerosene, ester solvents, silicone solvents or oils, fatty acids, dialkyl phthalates, C.sub.5 -C.sub.11 alcohols and fatty alcohols;
• (c) one or more emulsifiers in an amount of from 0.5 to 8% w/w and selected from the group consisting of mono-, di- and tri-sorbitan esters, polyoxyethylene sorbitan esters, mono- and poly-glycerol esters, ethoxylated nonionic emulsifiers, propoxylated nonionic emulsifiers and ethoxylated/propoxylated nonionic emulsifiers;
• (d) from 2 to 80% w/w of one or more propellants;
• (e) from 0 to 5% w/w of one or more oil phase soluble insecticides;
• and
• (f) water sufficient to bring the total composition to 100% w/w.