Melledobythus, Hlaváč, Peter, Nakládal, Oto & Jalžić, Branko, 2014

Hlaváč, Peter, Nakládal, Oto & Jalžić, Branko, 2014, Endogean and cavernicolous Coleoptera of the Balkans. XIV. Melledobythus bilandzijae, new genus and species of cavernicolous Bythinini (Staphylinidae: Pselaphinae) from the Island Mljet, Croatia, Zootaxa 3835 (4), pp. 564-572 : 565

Melledobythus gen. nov.

Type species. Melledobythus bilandzijae sp. n. Gender masculine.

Etymology. The name is the combination of Melleda, ancient name of the Island Mljet and “bythus” reflecting the affiliation of the genus to the tribe Bythinini .

Diagnosis. Small, anophthalmous Bythinini with eleven-segmented antennae, scape long and slender, antennomere III smaller than pedicel, palpomere IV slightly longer than wide, pronotum with two lateral foveae connected by antebasal sulcus, elytra lacking sutural striae.

Description. Body ( Fig. 1 ) shiny, light reddish-brown, with long, sparse setation on whole body. Head triangular, about as long as wide, eyes completely atrophied, supra-antennal tubercles ( Fig. 2 , sat) prominent, frontal fovea absent, vertexal foveae ( Fig. 2 , vf) well-defined, vertexal carina ( Fig. 2 , vc) short, clypeus ( Fig. 2 , cl) short, anterior margin rounded, with two setae, labrum ( Fig. 2 , lb) rhombic, expanded anteriorly with four long setae on each side. Mandibles ( Fig. 3, 4 , md) subtriangular and almost symetrical, with 5–6 teeth and sharply pointed apex. Maxilla with subrectangular cardo and triangular basistipes ( Fig. 4 , cd, bst), lacinia and galea ( Fig. 4 , lac, gal) short, palpifer ( Fig. 4 , ppf) long, about twice as long as palpomere I, with one long and one short apical seta; maxillary palpi ( Fig. 5 ) four-segmented, palpomere I miniscule ( Fig. 4 , plp), palpomeres II and III with many distinct granules, II very long, pedunculate at base, widest at apex, III slightly longer than wide, terminal palpomere pedunculate at base, with short dense setation, parallel-sided, tapered at apex. Labium ( Fig. 4 ) with short and transverse submentum ( Fig. 4 , smn), mentum ( Fig. 4 , mn) large, longer than wide, prementum ( Fig. 4 , pmn) short, labial palpi ( Fig. 4 , lp) two-segmented, palpomere II more than three times as long as I, with about three apical setae of different length. Gular plate ( Fig. 3 , gp) large with well-defined gular sutures ( Fig. 3 , gs) demarcating ventrally 'neck region' from anterior part of head, two gular tentorial pits ( Fig. 3 , gtp) fused. Antennae ( Fig. 5 ) short, reaching base of elytra, antennal club 3-segmented, scape about three times as long as wide and more than twice as long as pedicel, antennomere III much smaller than pedicel, III–VII subequal in size, VIII slightly more transverse, IX strongly transverse, terminal antenomere about as long as five preceding. Pronotum ( Fig. 6 ) wider than long, lateral antebasal foveae ( Fig. 6 , laf) well-defined and connected by shallow but well-defined antebasal sulcus ( Fig. 6 as). Prosternum ( Fig. 7 ) with long basisternal part ( Fig. 7 , bast), prosternal intercoxal process ( Fig. 7 , psp) long and sharp, median procoxal fovea absent, two, closely located lateral procoxal foveae ( Fig. 7 , lpcf) well-defined, hypomera ( Fig. 7 , hy) long, elongate and large, hypomeral ridge absent, replace by line of about 6 setae. Mesoventrite ( Figs. 7, 8 ) slightly longer than metaventrite, with two median mesoventral foveae ( Fig. 7 , mmvf) located in large depression and two large lateral mesoventral foveae ( Fig. 7 , lmvf), mesoventral ridge ( Fig. 7 , mvr) separating median and lateral parts of mesoventrite, mesocoxae separated by meso and metaventral processes ( Fig. 9 , mtvpp). Metaventrite ( Fig. 9 ) strongly transverse, with long median anterior metaventral process ( Fig. 9 , mtvap) and with two lateral metaventral foveae ( Fig. 9 , lmtf) located in middle of mesocoxal sockets, median posterior metaventral proces ( Fig. 9 , mtvpp) wide, moderately concave.

Elytra ( Fig. 10 ) longer than pronotum, each elytron with two basal ( Fig. 6 , 10 , bef), one subhumeral ( Fig. 6 , 10 , shef) fovea and subhumeral carina ( Fig. 10 , shc), lacking sutural stria.

Abdomen ( Fig. 11, 12 ) narrower than elytra, first visible tergite (IV) slightly less than twice as long as second (V), tergites V–VIII, each shorter than preceeding one, tergite IV with well-defined lateral tergal foveae ( Fig. 11 , ltf), paratergites IV–VI present. First visible sternite (III) at posterior margin with dense, long setae, second visible sternite (IV) about as long as V and VI combined, VII in middle shorter than VIII.

Legs relatively slender and long, with all tibiae simple, posterior tibiae slightly curved in apical third.

Aedeagus ( Fig. 13 ) elongate, symmetrical in dorso-ventral view, parameres pointed and separated at apex, bearing setae, endophallous with sclerotized corpuscles.

Sexual dimorphism: Not apparent.

Differential diagnosis. At first glance Melledobythus resembles genera Tychobythinus Ganglbauer, 1896 and Gasparobythus Poggi, 1992 . From Tychobythinus it is easily separated by the lack of sutural striae, always welldefined in Tychobythinus . From Gasparobythus it differs by having a well-defined pronotal antebasal sulcus that is absent in Gasparobythus , and by the long terminal maxillary palpomeres that are longer than the head, being always shorter than the head in Gasparobythus .

Figures

FIGURES 13. Melledobythus bilandzijae gen. & sp. nov., aedeagus, dorsal, scale 0.1 mm.

FIGURES 1 – 6. Melledobythus bilandzijae gen. & sp. nov., 1, male, dorsal habitus; 2, head, dorsal (cl — clypeus, fr — frons, lb — labium, sat — supra-antennal tubercles, vc — vertexal carina, vf — vertexal fovea, vt — vertex); 3, head, ventral (gp — gular plate, gs — gular suture, gtp — gular tentorial pits, md — mandibles, mn — mentum); 4, mouth parts, venter (bst — basistipes, cd — cardo, gal—galea, lac — lacinia, lp — labial palpi, md — mandibles, mn — mentum, mst — mesostipes, plp — maxillary palpomere I, pmn — prementum, ppf — palpifer, smn— submentum); 5, left maxillary palpi and antennae; 6, pronotum and base of elytra (as — antebasal suture, bef — basal elytral foveae, laf — lateral antebasal foveae, shef — subhumeral elytral fovea).

FIGURES 7 – 12. Melledobythus bilandzijae gen. & sp. nov., 7, prosternum and mesoventrite (bast — basisternal part, hy — hypomeron, lmvf — lateral metaventral fovea, lpcf — lateral procoxal fovea, mmvf — median metaventral fovea, msvp — mesoventral process, mvr — metaventral ridge, psp — prosternal process); 8, ventral habitus; 9, meso and metaventrite (lmtf — lateral metaventral fovea, msvp — mesoventral process, mtvap — median metaventral anterior process, mtvpp— median metaventral posterior process); 10, left elytron (bef — basal elytral foveae, shef — subhumeral elytral fovea, shc — subhumeral elytral carina); 11, abdomen, dorsal (ltf — lateral fovea); 12, abdomen, ventral