Patterns of morphological diversification in giant Berberomeloe blister beetles (Coleoptera: Meloidae) reveal an unexpected taxonomic diversity concordant with mtDNA phylogenetic structure

Abstract

Delimiting species boundaries is a complex challenge usually hindered by overlooked morphological diversification or misinterpretation of geographically structured phenotypic variability. Independent molecular data are extremely useful to characterize and understand such morphological diversity. Morphological and molecular variability of the non-phoretic and apterous, widely distributed, giant blister beetles of the genus Berberomeloe, were investigated within and between lineages across most of the distributional range of the genus. We used two mtDNA gene fragments to characterize genetic variability and to produce a time-calibrated phylogeny of the genus. Our results reveal several mitochondrial lineages, allopatrically, parapatrically and sympatrically distributed. Most clades are not distinguishable between each other based on morphometrics. However, no morphometric overlap is observed between two closely related clades, one of them occurring in sympatry with a distantly congeneric species (B. insignis), suggesting that sympatry could trigger morphological diversification. Although most species share a morphometric space, they can be morphologically identified by a combination of easily observed characteristic qualitative features. Based on the concordance between mtDNA clades and morphological units, we describe six new species of Berberomeloe (B. castuo sp. nov., B. comunero sp. nov., B. indalo sp. nov, B. yebli sp. nov., B. payoyo sp. nov. and B. tenebrosus sp. nov.), revalidate two taxa (B. maculifrons comb. nov. and B. laevigatus comb. nov.) and redefine B. majalis.

Catalogue, distribution, taxonomic notes, and conservation of the Western Palearctic endemic hunchback beetles (Tenebrionidae, Misolampus)

“…These evident patterns of morphological differentiation within M. ramburii, M. gibbulus, and M. goudotii may reflect a relatively recent history of isolation across populations, probably consequence of the existence of multiple isolated Pleistocene refugia (Abellán and Svenning 2014), as proposed for other flightless Iberian Coleoptera (Sánchez-Vialas et al 2020). In any case, these hypotheses require phylogeographic analyses to be properly tested.…”

What’s flashing in Kadamaian? A Note on Fireflies (Coleoptera: Lampyridae) in Kadamaian, Sabah

“…Deciding a taxonomical status based on minute morphological differences may be incorrect. This is because intraspecific phenotypic polymorphism may occur which is common in many species (Sánchez-Vialas et al, 2020;Yeong et al, 2018). In Lampyridae research, intraspecific variation was observed, such as the pronotum colour of Pteroptyx bearni from West versus East Malaysia and Pt.…”

A new systematic arrangement for the blister beetle genus Eurymeloe (Meloini, Meloidae, Coleoptera) with the description of a new species from Spain

“…To delimit species, we adopted the evolutionary species concept ( Wiley 1978 ; Wiley and Mayden 2000 ) in which a species is considered “a single lineage of ancestral descendant populations of organisms which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate” ( Wiley 1978 : 18). This concept combines implications derived from the phylogenetic species concept, such as reciprocal monophyly, with additional subjective properties (e.g., phenetic distinguishability and reproductive isolation, among other lines of evidence) that can be used to assess the historical fate of lineages ( Ruiz and García-París 2015 ; Sánchez-Vialas et al 2020 ).…”