Host Associations

Nearly all Auchenorrhyncha are plant feeders; the few known exceptions (e.g., Fulgoroidea: Achilidae and Derbidae) feed on fungi as nymphs. Auchenorrhynchans use a wide variety of plants including mosses, horsetails, ferns, cycads, conifers, and angiosperms, but the vast majority of species feed on flowering plants. Most species appear to be restricted to a single genus or species of plants. Many species, particularly among the xylem-feeding groups, normally use a few or a single plant species but are capable of feeding and developing on a variety of alternate hosts if the preferred host is not available. A few xylem-feeding species have extremely broad host ranges. For example, the meadow spittlebug, Philaenus spumarius, with over 500 documented food plants, has the broadest known host range of any herbivorous insect. Phloem- and mesophyll-feeding species, comprising the majority of Auchenorrhyncha, tend to have narrower host ranges than xylem feeders, and many species appear to use a single plant family, genus, or species. Host associations appear to be conservative in some auchenorrhynchan lineages. Delphacidae and Cicadellidae (Deltocephalinae) include large numbers of grass- and sedge-specialist species and are among the dominant herbivores in grasslands. Most of the major lineages of Auchenorrhyncha do not exhibit a distinct preference for any particular plant taxon and usually include both host-generalist and host-specialist species. Some species alternate hosts during different stages in the life cycle or in different seasons. For example, nymphs of many leafhoppers and treehoppers develop on herbs, but the adult females oviposit on a woody host.

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