The genus Binodoxys includes only nine species found in Europe, yet despite its frequent occurrence, it remains insufficiently studied. This study addresses this knowledge gap through an exhaustive literature review and material collection, and a compilation of a comprehensive list detailing tritrophic associations. Based on the available molecular data, we constructed a maximum likelihood tree for six European species. Several new hosts were identified for the first time, and the geographical distribution of one species was broadened. An identification key for females of European Binodoxys species is provided. Future studies should prioritize gathering host data and investigate the existence of cryptic species among polyphagous species. Furthermore, the status of the three species not analyzed in this study due to the lack of material should be investigated by encompassing both morphological and molecular approaches.

The water lily aphid is a cosmopolitan species that feeds on various plants. Its primary hosts are Prunus species from which they migrate to their secondary hosts – aquatic and semi-aquatic plants. So far, in Serbia, Rhopalosiphum nymphaeae is recorded to attack only three plant species as secondary hosts. In our study, conducted in September 2020, we have researched the association of water lily aphid with secondary hosts in wetland habitats. A total of 44 samples were collected from 16 localities. In addition to the plant species previously reported, in this study 11 secondary hosts are documented for the first time in Serbia. The most common trophic association of R. nymphaeae was with Salvinia natans which was registered in 13 localities. There is a high possibility of finding new records of secondary hosts, therefore, more research is needed to complete the information about the water lily aphid and its hosts in Serbia.