Releases ofMicroterys flavus(Howard) in selected citrus groves in south Texas reduced populations of brown soft scale,Coccus hesperidumL., for prolonged periods compared with groves exposed to chemical control. The theoretical potential of this encyrtid parasite is such that a single gravid female could produce sufficient offspring in 6–7 weeks to destroy 1,089,300 scales. Procedures might be developed that would overcome adverse effects on the parasites and assure the success of compensatory releases of this parasite for control of brown soft scale.