Biodiversity of the endangered coastal beetle Scarites laevigatus: is the northern Adriatic population a geographical subspecies or a case of introgressive hybridisation? (Coleoptera: Carabidae)

Abstract

The ground beetle Scarites laevigatus Fabricius, 1792 is a specialized predator occurring in the Mediterranean sandy shores, currently threatened with disappearance due to the widespread modification of beach ecosystems. The present study purposes a morphological analysis of the northern Adriatic form, described by Puel in 1938 as a subspecies with the name venetianus, in comparison with the typical form of this taxon and S. terricola. The examination of pronotum, elytra, body shape, male genitalia and wing development, suggests that the studied population is different from the nominotypical form and might originate from the introgressive hybridisation of S. terricola with the north Adriatic populations of S. laevigatus. This hypothesis is discussed in the light of current knowledge of the systematics and ecology of the putative parent species.

Relicts from Glacial Times: The Ground Beetle Pterostichus adstrictus Eschscholtz, 1823 (Coleoptera: Carabidae) in the Austrian Alps

“…However, the putative direction of this suggested phenomenon remains unclear with the data available. There is increasing evidence from many different animal species that range-wide (or across large parts of a species’ distribution) mitochondrial replacement is more common than previously thought [ 68 , 69 , 70 , 71 ] and hybridization/introgression has been repeatedly reported in carabid beetles [ 72 , 73 , 74 ], including the genus Pterostichus [ 43 , 75 ]. Unfortunately, here, mitochondrial data alone are insufficient to clarify which processes underlie the observed haplotype sharing between P. oblongopunctatus and northern P. adstrictus .…”