ABSTRACT
Once genetic improvement has been incorporated into a laboratory population, the steps required to maintain the genetic quality of the improved strain are similar to those required in retaining the genetic diversity present in the biotypes introduced for classical biological control. In this chapter, the author proposes to discuss genetic improvement. He deals with examples which include the dramatic build-up of the Amazon fly Metagonastylum minense (Tns.) in St.Lucia and Venezuela, the rapid establishment of the Cuban fly Lixophaga diatraeae in St. Kitts, and the acclaimed success of C otesia flavipes in northeast Brazil. The author mentions briefly Box's attempts to improve the perfomance of the tachinid Paratheresia claripalpis, a parasite of Diatraea spp., in Venezuela. He examines the failure, for many years, to get establishment of the tachinid fly L. diatraeae in Barbados and the initial failure of C. flavipes in the state of Sao Paulo, Brazil; in certain Caribbean islands; and in Venezuela.
