New food plants for insects Vilbasteana oculata (Hemiptera: Cicadellidae) and Otiorhynchus smreczynskii (Coleoptera: Curculionidae) in the Baltic region

Abstract

Vilbasteana oculata (hemipteran) and Otiorhynchus smreczynskii (beetle) are alien species in countries around the Baltic Sea, and they are continuing to spread. Sometimes when entering new areas where other plant species are found, herbivores tend to add to their range of food plants. Knowledge of the feeding trends of particular insect species can be useful in predicting possible changes in insect-plant trophic relationships in other regions where they expanding in range. This study looks at the feeding trends of two insect species – V. oculata and O. smreczynskii. The study was carried out mainly in Latvia, as well as in other expeditions in Estonia, Lithuania, Poland and Sweden. In this study, four Fraxinus and four Ligustrum species were confirmed as the new food plants for V. oculata. The main food plants for adults of O. smreczynskii probably originally belonged to the genera Ligustrum and Syringa. In this study, a number of alternative food plants have been recorded for the first time, generally woody and some herbaceous plants. Most of the newly registered food plants for O. smreczynskii belong to the families Oleaceae and Rosaceae. Other food plants belong to the families Adoxaceae, Celastraceae, Elaeagnaceae, Ericaceae, Grossulariaceae, and Rhamnaceae. V. oculata was confirmed in Poland (2017) and Sweden (2019) for the first time.