O. Merkl szerk.: Folia Entomologica Hungarica 68. (Budapest, 2007)

posteriad in lateral aspect, with a narrow dorsal lobe bordered with a series of long, strong, posteriorly directed setae. Apex of posterior process of pygophore abruptly narrowed, beak-shaped, strongly declivent posteriorly. Subgenital plate (Fig. 12) strongly incised at middle; apical half narrow, finger-like, apex rounded, slightly surpassing posterior process of pygophore; basal half rounded near incision, with long, strong, posteriorly directed setae. Stylus (Fig. 12) stout, apex strongly curved laterally, not surpassing apex of connective. Connective simple, connected with styli in its basal third, with two parallel arms fusing before apex of body. Aedeagus (Figs 13-15): caudal part of basal apodeme relatively narrow in dorsal aspect, lateral angles elongated, dorsolaterally elevated; shaft of aedeagus arising from middle of basal apodeme, with a pair of long, narrow, posteriorly directed processes, a pair of short lateral projections and a pair of short, anteriorly directed tubercles (Fig. 15). Structure of female genitalia. Ovipositor well developed. Posterior margin of abdominal sternite VII with three short projections, the medial one excised at its apex (Fig. 11). Measurements (in mm). Body length: male 3.70-4.05, female 4.09-5.05, length of vertex along meson: male 0.492-0.538, female 0.554-0.585, interocular distance: male 0.631-0.662, female 0.738-0.754, length of forewing: male 2.80-3.15, female 2.95-3.13, greatest width of forewing: male 1.00-1.13, female 1.05-1.15 Etymology - The new species is dedicated to Dr. JÓZSEF BÉRES, zoologist at Muzeul Maramuresului (Sighetu Marmatiei, Romania), in appreciation of his devoted and assiduous activity in promoting the zoological exploration in Maramures. Comparison with related species - According to the external morphology and male genitalia, the new species belongs to Diplocolenus, subgenus Erdianus. It is most similar to Diplocolenus penthopitta, and the two species are apparently closely related taxonomically. The characters suitable for differentiating these species as well as D. quadrivirgatus, usually occurring together with the above two species, are given in Table 1. Evolutionary notes - The geographic isolation of montane habitats led to speciation in several groups of Auchenorrhyncha and therefore is causal for considerable diversity in the European fauna. KNIGHT (1974) recognized!), quadrivirgatus, D. quadricornis RlBAUT, 1959 (France), D. nigricans (KIRSCHBAUM, 1868) (Italy and Switzerland) and D. penthopitta as a monophyletic evolutionary lineage within the (apparently not monophyletic) subgenus Erdianus. Very probably all of the above species, together with D. beresi sp. n., are result of relatively recent speciation events facilitated by isolation of montane biotopes in the Carpathians and Alps. KNIGHT (1974) noted that within the above monophyletic group, the number of apomorphic characters show an increase in the direction quadrivirgatus — quadricornis — nigricans —penthopitta. If accepting this opinion, D. beresi sp. n. should be placed between D. nigricans and D. penthopitta.