Three new species of Icaia Linnavuori (Hemiptera: Cicadellidae: Deltocephalinae) from Peru and distinction of the genus from Athysanella Baker
Four undescribed species of Icaia Linnavuori were identified from collections in montane grasslands of Peru. Three of these are illustrated and described as new species, and the remaining species, known only from one female, is illustrated. The new species are I. straminea sp. nov., I. laoroya sp. nov., and I. cygnus sp. nov. A comparative study of 18 morphological characters for 14 species of Icaia and Athysanella Baker was undertaken to reassess their current circumscriptions. Parsimony analysis of these characters recovered each genus as a monophyletic group and the strict consensus tree is presented to provide a preliminary view of the generic and subgeneric phylogeny of this New World group of Chiasmini. Several derived characters of the male genitalia were found that unite most of the species currently placed in Athysanella. However, three species currently placed in A. (Diphipyga) retain the plesiomorphic states for these characters. A. (Diphipyga) is reinterpreted to contain only these three species, A. (D.) mexicana Johnson, A. (D.) nimbata Ball & Beamer, and A. (D.) secunda Blocker & Wesley. Athysanella rubicunda Ball & Beamer and A. triodana Ball & Beamer are reinstated in Athysanella (Amphipyga). No uniquely identifying and universally shared characters were found that unite all species of Icaia, but a combination of similarities in external morphology and male genitalia to described species of Icaia, a lack of characters that define other genera of Chiasmini, and their South American distribution allow placement of the new species into Icaia.