Field Evaluation of Natural Enemies ofTamarixspp. in Southern France

During 1993, potted plants ofTamarix ramosissimaC. F. Ledebour (saltcedar) from the United States of America andT. gallicaL. from France were placed underTamarix gallicatrees at Sète and Vendémian, southern France, and the natural enemies that attacked these plants were recorded. The most promising natural enemies found were three species ofPsectrosema(Diptera: Cecidomyiidae);Hypophyes pallidulus(Gravenhorst),Corimalia tamarisci(Gyllenhal), andConiatus tamarisciF. (Coleoptera: Curculionidae);Stylosomusprob. tamaricis (Herrich-Schaffer) (Coleoptera: Chrysomelidae); andAgdistis tamaricis(Zeller) (Lepidoptera: Pterophoridae). The host specificity of these insects was studied in a field test during 1994. Of the 11 plant species tested, none of the economically important plants and neitherTamarix aphylla(L.) nor any of the nine genera of plants outside the family Tamaricaceae were attacked. The above mentioned natural enemies seem to be specific feeders on saltcedar and are recommended as prospective agents for biological control ofT. ramosissimain the United States.