From bites to bytes: analyzing leaf damage area with neural networks to assess Altica oleracea's (Coleoptera, Chrysomelidae) preferences for native and invasive plants from the Onagraceae family

Abstract

The Enemy Release Hypothesis posits that invasive plants in secondary ranges are freed from phytophage pressure, yet local phytophages may adapt to these invasive species over time. This study investigated the dietary preferences of Altica oleracea in relation to three native (Chamaenerion angustifolium (L.) Scop., Epilobium montanum L., and E. hirsutum L.) and three invasive (E. adenocaulon Hausskn., Oenothera biennis L., Oe. rubricaulis Kleb.) plant species from the Onagraceae family. A neural network was employed to automate the calculation of leaf damage area for assessing the phytophagous insects' dietary preferences. A. oleracea demonstrated a pronounced preference for Chamaenerion angustifolium compared to other Onagraceae species, irrespective of their invasive status. Among imago, no significant preference was observed between native and invasive Epilobium species or between two Oenothera species. However, the larvae were more discerning and avoided Oe. biennis, rearing on which led to the least weight gain by larvae. The adult beetles' inability to differentiate between plants unsuitable for larvae could lead to an evolutionary trap. The prevalence of Wolbachia infection in the A. oleracea population may influence the further evolution of adaptability to invasive species and the formation of dietary preferences.