Abstract In Patagonia, knowledge about the interaction among tephritids and the native flora is very scarce. In this study we identified for the first time two tephritid species (Cecidochares sp. and Neosphaeniscus m-nigrum) associated with the capitula of Chuquiraga avellanedae. This is the first record of a host plant for the genus Neosphaeniscus. Cecidochares sp. was more abundant and had a shorter development time than N. m-nigrum. Also, two families of parasitoid wasps (Pteromalidae and Eurytomidae) were registered. Further studies are needed to understand the impact of these tephritids on C. avellanedae fitness and their potential to control its populations.

The biocontrol agents Diachasmimorpha tryoni (Cameron) and Diachasmimorpha longicaudata (Ashmead), two endoparasitoids of fruit fly larvae, were introduced to Argentina in 1999 with the purpose of renewing the employment of natural enemies against Ceratitis capitata (Wiedemann). For this reason, the general procedure and maintenance of the host and parasitoids rearing in the laboratory are described, and the results of one year insectary production (January-December/2000) of both D. tryoni and D. longicaudata are discussed. Data are presented of the progeny production, offpring sex ratio, host parasitism percentage, and pupal viability per parasitoid rearing cage during 15 generations of D. longicaudata and D. tryoni reared using late third instar larvae of C. capitata. New perspectives are discussed on the establishment of a biological control program for C. capitata and Anastrepha fraterculus (Wiedemann) in Argentina by using parasitoid augmentative releases.

Con el propósito de reanudar la utilización de enemigos naturales contra la especie exótica Ceratitis capitata (Wiedemann), fueron introducidos a la Argentina en 1999 los agentes de control biológico Diachasmimorpha tryoni (Cameron) y Diachasmimorpha longicaudata (Ashmead), dos endoparasitoides de larvas de tefrítidos. Por este motivo, en este trabajo se describen los procedimientos de cría en laboratorio del huésped y de ambas especies de parasitoides y, se presentan y discuten los resultados de un año de producción de D. tryoni y D. longicaudata a mediana escala (enero-diciembre/2000). Se realizó un análisis comparativo de los datos obtenidos sobre la producción de descendientes, proporción sexual, porcentaje de parasitismo y viabilidad de puparios por jaula de cría durante 15 generaciones entre ambas especies de parasitoides exóticos, utilizando como huésped larvas de C. capitata del tercer estadio de siete días de edad. Además, se discuten las posibilidades para implementar el control biológico aumentativo contra C. capitata y Anastrepha fraterculus (Wiedemann) en el país.