Platyderus marianicus, Ruiz-Tapiador & Anitschenko, 2007

Ruiz-Tapiador, Ildefonso & Anitschenko, Alexander, 2007, Description of a New Species of Platyderus Stephens, 1827 (Coleoptera, Carabidae) from the Iberian Peninsula, Baltic Journal of Coleopterology 7 (2), pp. 185-190 : 186-189

Platyderus marianicus sp. nov.

Type Material. Holotype: 1 Male. Puerto de Valderrepisa , Sierra Madrona, Ciudad Real, 1100 m; 30.III. 2006, Espańa: Ruiz-Tapiador leg. (coll. Ruiz-Tapiador)

Paratypes: Same data as holotype, 1 Male (coll Anischenko), 2 Females (coll Ruiz-Tapiador) 1 Female ( Colección Museo Nacional de Ciencias Naturales , Madrid) ; idem, 12.III.2007, Ruiz-Tapiador leg. 1 Male ( Colección Museo Nacional Ciencias Naturales , Madrid) , 1 Female (Coll J. P. Zaballos, Madrid) , 1 Female (coll D. Wrase, Berlin), 1 Male and 2 Females (coll Ruiz-Tapiador )

Length, 7.5-8.5 mm. Upper part of the body chestnut brown, with lighter extremities.

Head rather flat, with isodiametric micro-reticulation on the forehead. Very superficial frontal grooves with an absence of punctating. Eyes moderately prominent.

Pronotum transverse 1,2 times wider than long, widest before middle, brilliant disk, without micro-reticulation, impunctate; proepisterna with micro-reticulation strongly transverse and sparsely punctuate. Hind angles rounded; the basal foveae does not reach the rear edge and the lateral sides are convex, with thick punctating. Non-dotted basal surface, slightly rough longitudinally. Basal margin visible. Longitudinal groove very deep.

Sub-oval elytron with remarcable scaleform micro-reticulation in both sexes, striae deep and smooth and intervals convex with very fine, sparse, and irregular punctuate in front half. Middle dorsal pore located on the third striae.

Structure of the internal middle lobe of the male aedeagus is shown in figures 1-4 . It is characterized by a very prominent B protuberance, which contracts with VLR protuberance which is scarcely marked. From a ventral view, BLR and BLL protuberances show a bulky look and a symmetric layout in relation to the aedeagus axis.

Taxonomic considerations. The description of new species in the Platyderus genus faces two important difficulties. On the one hand, the extensive number of species that are already known. And on the other hand, their important morphological uniformity. These causes have led to an increasing difficulty in the differentiation of species when using traditional characters as a basis. This problem has already been outlined in other genus of Carabidae (Zaballos, 2005) , which results in an obligation to search out new elements for differentiation. Use of the threedimensional structure of the aedeagal internal sac provides a new tool for discrimination, and it may allow a new approach of the phylogenesis.

The only species of the “ ruficollis” group, which is geographically close to the P. marianicus n. sp. is P. marduk (Anichtchenko, 2003) ocurring in the area surrounding Cazalla de la Sierra (Sevilla). This are clearly differentiated from new species because the inter-striations of the elytrons are strongly concave and with thick punctating, apart from the shape of the internal sac ( fig. 9–12 ). The volume of BLR and BLL protuberances show a very bulky look in P marianicus , while they are less developed in P. marduk . As far as VLR protuberance is concerned, the rate of development is quite different from the previous one, since it is very small in P marianicus but very well marked in P. marduk

Within this group, the species close to P. marianicus n. sp. is P. rotundatus (Chaudoir, 1866) , but can be differenciated from the new species by its impunctate frontal grooves.

Its aspect is very similar, with the most obvious external difference residing in the micro-reticulation. In the case of the P. rotundatus this difference is less marked in the females, practically disappearing in the case of the males. In that pertaining to its morphology, in the P. marianicus it is pointy, while in the P. rotundatus it is blunted. The most pronounced difference can be appreciated again, in the different configuration model of its internal sac, as can be seen in the corresponding figure ( fig 4-8 ). The difference between these two species is found in the rate of development of B and VLR protuberances. B is well developed in P. marianicus while VLR is poorly marked. However, B is scarcely developed in P. rotundatus , while VLR has developed very well.

As a final conclusion, it can be advanced that a detailed revision of the genus, as of the consideration of this new character, is destined to bring about the discovery of new species, thus forcing a reconsideration of the group’s phylogenesis.

Etymology. The origin of this new specie’s name P. marianicus n. sp., refers to the Marianica Cordillera, name given by Estrabon to the Sierra where the typical series inhabits and which has its origin in the Roman Proconsul by the name of Mario Sexto who was in charge of running the mines located in this area.

Figures

Figs. 1-12. Internal sac of the middle lobe of the aedeagus 1-4) P. marianicus sp. nov. (Puerto de Valderrepisa, Sierra Madrona), Holotype; 5-8) P. rotundatus Chaudoir (Sierra Arana); 9-12) P. marduk Anichtchenko (Cazalla de la Sierra). Name of structures of the internal sack (DA: dorsal-apical, VA: ventral-apical, B: basal, DLR: dorsal-lateral right, DLL: dorsal-lateral left, BLR: basal-lateral right, BLL: basal-lateral left and S: sclerite).