2026/04/01 by Benjamin Zelvelder, Gael J. Kergoat, Laure Benoit +3 · 1 voice
Agricultural and Biological Sciences · #Plant Parasitism and Resistance #Insect-Plant Interactions and Control #Plant Diversity and Evolution
paper · doi:10.1098/rspb.2026.0100
Phytophagous insects have specialized on virtually every plant lineage. Parasitic plants, however, are uncommon hosts. Among insects, only a single lineage of weevils, the Smicronychini, has successfully radiated on both parasitic and non-parasitic plants in a large panel of distantly related Asterid families. This unusual pattern suggests that major host plant shifts have occurred over the course of their diversification. Through the analysis of a phylogenomic dataset, we reconstruct for the first time their evolutionary history and ancestral host-plant repertoire. Our results show that independent host plant shifts occurred both from parasitic to non-parasitic hosts and between distinct parasitic lineages. These results suggest that host shift mechanisms can be driven by ecological opportunities provided by plant-plant interactions. This first evidence of extreme insect host plant shifts, apparently mediated by parasitic plant-plant interactions, emphasizes the core importance of ecological interactions as driving forces behind insect host plant shifts.