New data on morphometrics, distribution and ecology of Mioscirtus wagneri (Kittary, 1849) (Orthoptera, Acrididae) in Spain: is maghrebi a well defined subespecies?

Abstract

We studied different populations of Mioscirtus wagneri (Kittary, 1859) in Spain assigned to subspecies maghrebi by Fernandes (1968) and obtained some new records for the species. To see if maghrebi is a consistent taxon for the Iberian populations, we performed a morphometric analysis involving 53 individuals from different origins considering body size (front of the head to tip of the abdomen); the shape of pronotum and presence of a second anterior notch or sulcus; length of the antennae and epiphallum, according to the characters used to define subspecies maghrebi. If maghrebi is consistent, we would expect intermediate sizes between wagneri and rogenhoferi, the other two well separated subspecies considered for M.w. However, in our measurements we obtained that body size is not intermediate between M. w. wagneri and M. w. rogenhoferi contrary to expectations if assuming the existence of maghrebi. Body size is similar to wagneri and further, we recorded some of the smallest individuals described so far. Also, the pronotum varied widely across and within populations showing different phenotypes that formerly were used to separate maghrebi and wagneri. Taking into account body size, pronotum, length of antenna and epiphallum, we think that differences between the studied Spanish populations and wagneri form are not enough to assign the studied populations to maghrebi. In the studied area, M.w. shows a narrow ecological niche inhabiting shores or proximities of hipersaline lagoons wherever Suaeda vera (Forsskål 1791, Chenopodiacea) is present, M.w. uses this plant as refuge and food. The species also inhabits bare saline low grounds with scattered S vera. It presents a markedly discontinuous and patchy distribution in Spain, showing up punctually, where the microhabitat is appropriate. We obtained a morphometric variability with a significant association between body size and locality, and between body size and the colour of posterior wings in males. Because of its wide range disjunction, its discontinuous regional distribution and morphological variability, we believe that M.w. is an interesting species to investigate possible substructuring of populations in which we probably may recognize ecological forms or varieties that deserve deeper and further study.