In such cases the weeps consist of small-diameter plastic, clay or metal pipes extending through the wall to a layer of porous backfill. Typically, weeps are arranged to direct water which may have entered an assembly from outside back to the outside.
A few of several safe household chemicals to use are vinegar, dishwashing soap and rubbing alcohol, according to an Oregon State University Extension Service publication called Using Home Remedies to Control Garden Pests, (EC 1586). The publication, complete with photos, is available free of charge online.
Hi-Yield 55% Malathion Insecticide Spray is for outdoor home garden use on select fruits, vegetables, and other plants to treat aphids, bagworms, thrips, spider mites, lace bugs, adult Japanese beetles, tent caterpillars, and other pests. Malathion Insecticide Spray comes in a convenient size for home garden use.