Diversity and host plant utilization of leaf-mining beetles of Chrysomeloidea (Coleoptera) in Japan

The superfamily Chrysomeloidea (Cerambycidae + Chrysomelidae + Megalopodidae) encompasses a diverse phytophagous beetles, whose larvae exhibit internal or external feeding on leaves, wood, or roots of many plants. Through extensive research on leaf-mining insects in Japan, 64 species of Chrysomeloidea were confirmed to engage in leaf-mining behavior during their larval stages infesting tracheophytes, and comprising 2 Cerambycidae, 9 Megalopodidae, and 53 Chrysomelidae.

This study presents an overview of the host plants and mining patterns of these 64 leaf-mining beetle species and describes two new species, Sphaeroderma komiana Kato, sp. nov. and Dactylispa adinae Kato, sp. nov. The leaf-mining beetles demonstrate a broad host range including Equisetales, Polypodiales, Cycadales, and 23 orders of angiosperms. Particularly notable diversification was observed on Polypodiales (within Halticorcus), Ranunculaceae (Argopus and Sphaeroderma), Celastraceae (Zeugophora), and Oleaceae (Argopistes).

Host specificity greatly varied among the reported 64 beetle species: 29 spp. species-specific; 12 spp. genus-specific; 16 spp. family-specific; 2 spp. order-specific; 5 spp. non-specific even at order level. The five non-specific species (Argopus punctipennis, Sphaeroderma nigricolle, Dactylispa angulosa, Notosacantha ihai, and N. loochooana) are associated with multiple plant orders while maintaining specificity to a small number of genera belonging to phylogenetically distant plant families.

This pattern, termed as extended host specificity, suggests recent host shifts across plant families without substantial expansion of host ranges.