Genus Flexamia : new species, phylogeny, and ecology

Abstract

Eight new species of Flexamia DeLong are described, and two Mexican species previously synonymized are reinstated. Species are assigned to 13 species groups; keys are presented for the groups and for the 44 recognized species. Host data, in many cases with oligophagy coefficients, are presented for 37 of the species. Many species specialize on native, dominant, perennial, choridoid or panicoid grasses; some are monophagous. Seven sister species pairs specialize on the same (or a closely related) grass species; in addition, four closely related species appear to be restricted to Bouteloua curtipendula . Few if any specialists colonize their host throughout its entire range. Ecological factors such as phenology and/or host patchiness strongly influence geographic distribution. An intuitive phylogeny is proposed and is used as a basis for constructing 18 character transformations. The genus Flexamia probably originated in Mexico by division of an ancestral lineage from which the modern genus Spartopyge also diverged.