Host range of Tetramesa romana Walker (Hymenoptera: Eurytomidae), a potential biological control of giant reed, Arundo donax L. in North America

The eurytomid wasp, Tetramesa romana Walker was evaluated as a potential biological control agent of the invasive reed grass, Arundo donax in North America. No-choice tests and timed behavioral studies were used to determine the fundamental host range of two genotypes of the wasp collected from Granada, Spain and Perpignan, France. Thirty-five species, including two genotypes of A. donax and seven ecotypes of Phragmites australis, along with closely related grasses, economic grasses and habitat associates were tested. Complete development of both T. romana genotypes was restricted to A. donax and Arundo formosana. The mean number of offspring produced from individual females was significantly greater on the A. donax genotype from Laredo, TX (12.8 ± 3.2) as compared to the genotype from San Juan, TX (3.9 ± 1.0) and A. formosana (0.8 ± 0.4). In behavioral studies, ovipositor probing was observed on 15 of the 35 species but development only occurred on A. donax and A. formosana. Based on our results, the wasp T. romana appears to be specific to the genus Arundo and is unlikely to harm native or cultivated plants in the Americas.