What drives the reduction of hindwings in Galerucinae sensu stricto (Insecta, Coleoptera, Chrysomelidae)? A case study based on the Taiwanese fauna

Most Taiwanese species of Galerucinae s. str. have been revised taxonomically in recent years. In Taiwan, reduction of hindwings occurs in 37 species in eight genera. A citizen science-led fieldwork project (Taiwan Chrysomelid Research Team, TCRT) targeting the biology of galerucine species has produced many specimens for morphological and taxonomic study and allowed the development of evolutionary scenarios to explain hind-wing reduction in the following genera: <i>Paraplotes</i> Laboissière, <i>Lochmaea</i> Weise, <i>Shairella</i> Chûjô, <i>Furusawaia</i> Chûjô, <i>Sikkimia</i> Duviver, <i>Taiwanoshaira</i> Lee & Beenen, <i>Apterogaleruca</i> Chûjô, and <i>Hirtigaleruca</i> Chûjô. The results reveal that the drivers of the reduction of hindwings vary across different galerucine genera in Taiwan based on character complexes involved in the transformations.