The tribe Dysoniini is widely distributed in the Neotropics, ranging from northeastern Mexico across Central and South America to northern Argentina. In the latter subcontinent it is most diverse. These tettigoniids are remarkable for their lichen- and bryophyte-mimicking camouflage and for having a particularly elevated vertex, which is unusual in the family Phaneropterinae.
A cladistic analysis for 23 terminal taxa has been performed (20 in the ingroup and 3 in the outgroup), using 76 morphological and ecological characters in order to prove monophyly of the following genera and tribes: Hammatoferina n. subtr. (including Hammatofera), Markiina n. subtr. (Machimoides (Machima (Apolinaria (Lichenodraculus + Markia)))) and Dysoniina n. stat. (Quiva (Yungasacris (Dissonulichen (Alexanderellus n. gen. (Paraphidnia + Anaphidna) (Dysonia (Lichenomorphus + Lichenodentix)))))). The tribe’s genera resulted as monophyletic, except for Dysonia sensu Gorochov, so it was necessary to revalidate generic status for Dissonulichen n. stat. to recover monophyly for Dysonia. The three aforementioned subtribes and a new subgenus Dissonulichospinus n. subgen. (within Dissonulichen n. stat.) are proposed, as well as five new combinations of species so far included in Dysonia: Alexanderellus mariposa n. comb., Dissonulichen diffusus n. comb., D. ornatus n. comb., D. elegans n. comb. and Lichenomorphus pirani n. comb. Four species names are considered as synonyms: Hammatofera brasiliensis n. syn. (under H. nodicornis), Dysonia similis n. syn. (under Dissonulichen minensis), Dysonia cuiabensis n. syn. (under Dissonulichen hebardi) and Lichenomorphus nigriventer n. syn. (under L. puntifrons). Dysonia lamellipes is considered a nomen dubium.
Characters referring to camouflage, mimicry, and behaviors associated with these adaptative preferences were optimized. Optimizations for structural phylogenies were indicated on each of the optimized characters, displaying nodes in which the different optimizations by characters differ. Characters analyzed on the ambulatory behavior of the studied taxa are closely related to the type of mimicry or camouflage occurring in each group, so those taxa that camouflage in foliose lichen move in a slow, circumspect fashion, contrasting to taxa mimicking crustose or fruticose lichen, which simulate lichen parts stirred by a breeze. This most effective strategy makes them almost impossible to spot in their natural habitat. Likewise, species with wasp mimicry tend to show behaviors that make their imitation strategy more efficient. The ancestral state of the tribe is a phyllomorphic type (leaf camouflage) as is usual in most genera of the family Phaneropterinae. The appearance of camouflage and mimicry in the species of the tribe is discussed, and how these converge with taxa of other areas of the planet. The relationship between optimized characters is then grouped in the most parsimonious tree, indicating frequency and relation between taxa and characters.
A biogeographic dispersal-vicariance analysis of the tribe’s genera indicates that the ancestral area is in the Brazilian Shield as the only resulting ancestral distribution, with a secondary center of radiation in the Andes. Four vicariant events are postulated: 1) The differentiation of some genera by the rising of the Andes, 2) forming a barrier between species groups of the genus Markia. 3) Expansion from the ancestral area towards the Amazon and 4) the Andes.
Diagnoses and a pictorial key to the identification of all genera, plus conventional keys for identification of all species are provided, along with distribution maps. A list presents all taxa of the tribe within the proposed classification, including distribution data, depositories of type specimens, and additional comments.
