title: Montane and coastal species diversification in the economically important Mexican grasshopper genus Sphenarium (Orthoptera: Pyrgomorphidae).
abstract: The genus Sphenarium (Pyrgomorphidae) is a small group of grasshoppers endemic to México and Guatemala that are economically and culturally important both as a food source and as agricultural pests. However, its taxonomy has been largely neglected mainly due to its conserved interspecific external morphology and the considerable intraspecific variation in colour pattern of some taxa. Here we examined morphological as well as mitochondrial and nuclear DNA sequence data to assess the species boundaries and evolutionary history in Sphenarium. Our morphological identification and DNA sequence-based species delimitation, carried out with three different approaches (DNA barcoding, general mixed Yule-coalescent model, Bayesian species delimitation), all recovered a higher number of putative species of Sphenarium than previously recognised. We unambiguously delimit seven species, and between five and ten additional species depending on the data/method analysed. Phylogenetic relationships within the genus strongly support two main clades, one exclusively montane, the other coastal. Divergence time estimates suggest late Miocene to Pliocene ages for the origin and most of the early diversification events in the genus, which were probably influenced by the formation of the Trans-Mexican Volcanic Belt. A series of Pleistocene events could have led to the current species diversification in both montane and coastal regions. This study not only reveals an overlooked species richness for the most popular edible insect in Mexico, but also highlights the influence of the dynamic geological and climatic history of the region in shaping its current diversity.
authors.affiliation: Colección Nacional de Insectos, Instituto de Biología, Universidad Nacional Autónoma de México, 3er. Circuito exterior s/n Cd. Universitaria, Copilco, Coyoacán, A.P. 70-233, C.P. 04510, D.F., México, Mexico.
authors.forename: Carlos
authors.initials: C
authors.lastname: Pedraza-Lara
authors.affiliation: Instituto Tecnológico de Cd. Victoria, Blvd. Emilio Portes Gil No. 1301, C.P. 87010, Ciudad Victoria, Tamaulipas, Mexico.
authors.forename: Ludivina
authors.initials: L
authors.lastname: Barrientos-Lozano
authors.affiliation: Instituto Tecnológico de Cd. Victoria, Blvd. Emilio Portes Gil No. 1301, C.P. 87010, Ciudad Victoria, Tamaulipas, Mexico.
authors.forename: Aurora Y
authors.initials: AY
authors.lastname: Rocha-Sánchez
authors.affiliation: Colección Nacional de Insectos, Instituto de Biología, Universidad Nacional Autónoma de México, 3er. Circuito exterior s/n Cd. Universitaria, Copilco, Coyoacán, A.P. 70-233, C.P. 04510, D.F., México, Mexico. Electronic address: azaldivar@ib.unam.mx.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Zaldívar-Riverón
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D017344:Genes, Insect; D006110:Grasshoppers / Q000033:anatomy & histology / Q000145:classification*; D008800:Mexico; D008957:Models, Genetic; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: DNA Barcoding; Introgression; Mesoamerica; Neotropics; Species limits