A method of treating screwworm (larvae of Cochliomyia americana) infested wounds in goats and sheep so that all larvae leaving the wound after treatment are collected, is descr. Two soluble pine oils, when combined with 95% nicotine and methyl thiocyanate, respectively, and benzol with a cotton plug in the wound were effective larvicides for the treatment of wounds in goats and sheep infested with screwworms.