Epiblema tetragonana and Epinotia ustulana (Lepidoptera: Tortricidae), two potential biological control agents for the invasive plant, Rubus ellipticus

•Consideration of leaf-rolling moths as biocontrol agents for Rubus ellipticus.•Larvae of both moth species developed on plants in the genus Rubus.•Both moth adults showed a strong preference for R. ellipticus over other species.•Leaf-rolls by both species were only found on R. ellipticus in the field.•Both are widely distributed and abundant in southwestern China.

Himalayan yellow raspberry, Rubus ellipticus is one of the world’s 100 worst invasive alien species. The plant has become a serious problematic weed in Hawaii, USA and is naturalized in many other countries. Screening of potential biological control agents is being conducted in its native region in Asia. In this paper, we report on the field distribution, abundance and host specificity of two leaf-rolling moth species, Epinotia ustulana and Epiblema tetragonana (Lepidoptera: Tortricidae). In larval non-choice tests both species only developed on plants in the genus Rubus. However, in adult choice oviposition tests, both leaf rollers showed a strong preference for R. ellipticus over other species. Furthermore, leaf-rolls by these two insects were only found on R. ellipticus in the field. These results indicate the moths have a narrow host range. Our field surveys also showed that both moth species are widely distributed in Yunnan Province, southeastern China, with up to 115 leaf rolls per plant, suggesting high levels of damage. These findings indicate that the two insects have considerable potential for biological control of R. ellipticus, though further host range tests should be conducted using more native plant species in Hawaii.

Graphical abstractField survey sites in Southwestern China. Dots indicate where Rubus ellipticus and Epiblema tetragonana and Epinotia ustulana were found, circles indicate where only R. ellipticus but no E. tetragonana and E. ustulana were found.Figure optionsDownload full-size imageDownload as PowerPoint slide