Abstract The objective of these tests was to evaluate the performance of several insecticides that might be used to control FCB larvae. Textile resistance tests outlines by the Chemical Specialities Manufactures Association (CSMA) were modified to assess the efficacy of direct contact sprays and residual deposits. Larvae were tested because only immature FCB damage materials such as woolen or contaminated fabrics, leather, furs and feathers. Adults are short-lived compared to larvae and reportedly feed on pollen and nectar. FCB larvae for these tests were collected from cultures maintained at 27°C, 70-75% RH on medium comprised of dry dog chow, yeast and turkey feathers. Approximately half-grown larvae (2-3 mg, 3 mm long), which were retained on a no. 16 screen, were placed on flat glass beneath a warm light bulb. Larvae were aspirated into gloss shell vials as they moved to the edge of the glass. Five groups of 15 larvae placed in a clean 500 ml beaker were sprayed with two pumps (0.5 ml) from a deVilbiss #152 bulb sprayer from ca 7 inch. The thoroughly wetted larvae were transferred to filter paper to remove excess spray before they were placed in 26 sq cm plastic boxes the floors of which were covered with wool felt lightly dusted with a dog chow-yeast mixture. For residual activity, 5 groups of 20 larvae were confined to 26 sq cm felt treated with 0.13 ml dilute insecticide (1%=73 mg ai/sq ft.) The number dead was recorded ca daily up to 14 days. Each piece of wool was tested only once. Treatments were evaluated 28 and 56 days old.