Sexual dimorphism of Dyschiriini (Coleoptera, Carabidae): Comparative morphological SEM study of palpi sensilla and its possible role in intraspecific chemical communication.

Sexual dimorphism in Dyschiriini (Coleoptera, Carabidae) consists of the presence of an autapomorphic sensory area in apical palpomeres of males, here named as Male Palpi Sensory Area (MPSA). In this work, microstructure of palpi, with focus on MPSA, is characterized and formally described using Scanning Electron Microscopy (SEM). Interspecific variability among 13 species and three subgenera of Dyschirius Bonelli, 1810 and one species of Reicheiodes Ganglbauer, 1891 is assessed. Palpi of studied Dyschiriini presented up to 4 sensilla classes (coeloconica, basiconica, digitiformia, trichodea) in both sexes, while males had one more class (sensilla placodea) found grouped in MPSA. Measurements of sensilla and MPSA are provided. Differences among taxa corresponded to development grade of MPSA and its number of sensilla placodea. The MPSA of Dyschirius (Dyschirius) thoracicus Rossi, 1790 were clearly different to the rest of the studied subgenera and species of Dyschirius and Reicheiodes, whose MPSA were similar and had slight intraspecific variability. We suggest that function of MPSA is likely detection of female pheromones, which would evidence chemical communication between sexes. We hypothesize that evolution of MPSA could be related to burrowing habits of Dyschiriini and its possible sexual behavior in soil tunnels. Study of MPSA may help to elucidate phylogenetic relationships among members of the tribe.

Taxonomic reconsideration of the subspecific complex of Laemostenus (Antisphodrus) cazorlensis (Mateu, 1953) (Coleoptera, Carabidae, Platyninae).

In this article we present a comparative study between the three subspecies of Laemostenus (Antisphodrus) cazorlensis (Mateu, 1953) (Coleoptera, Carabidae), a representative carabid of the cave fauna of Jaén and Albacete (southern Spain). The aim of this work was to examine the validity of the characters typically used to distinguish the subspecies L. (A.) c. cazorlensis (Mateu, 1953), L. (A.) c. divergens (Mateu, 1953) and L. (A.) c. seguranus (Vives Vives, 1982) and check if they support the actual subspecific classification. For this purpose, a morphometric study of the pronotum and a morphological study of the male and female genitalia were carried out on 161 individuals of the three subspecies from the different geographic territories within the known distribution range of the species. An ANOVA analysis was run to support the results of the morphometric study developed with the total of studied samples. The results suggest that none of the studied characters can be used to characterize any of the subspecific taxa. Besides, the karstic profile of the ground in where this species inhabits could facilitate the genetic flow between its populations, so it is possible that they are not completely isolated. We conclude that the observable differences between individuals of Laemostenus (Antisphodrus) cazorlensis for the studied characters reflect intraspecific variability, and do not support a subspecific classification of the species. We propose the synonymization of the two non-typical subspecies of Laemostenus (Antisphodrus) cazorlensis with the typical one and, therefore, with the specific taxa.