Trichomyia stephani, Beran, Bernadett, Doczkal, Dieter, Pfister, Kurt & Wagner, Rüdiger, 2010

Beran, Bernadett, Doczkal, Dieter, Pfister, Kurt & Wagner, Rüdiger, 2010, Two new species of Psychodidae (subfamilies Trichomyiinae and Psychodinae) from Germany associated with decaying wood, Zootaxa 2386, pp. 59-64 : 60-62

Trichomyia stephani sp. nov

Material: 13(holotype) Germany, Rhineland-Palatinate, Kirchheimbolanden, nature reserve Albertskreuz (coppice management), 400 m a.s.l. 23. May –7. June 2002, malaise-trap, leg. D. Doczkal; 13 (paratype) 12. July 2007, Germany, Bavaria, Munich, Reitschule [48°09’18” N, 11°35’22” E], 511 m, CDC-light trap, leg. B. Beran; 13 (paratype) 19. July 2007, Germany, Bavaria, Munich, Reitschule [48°09’18” N, 11°35’22” E], 511 m, CDC-light trap, leg. B. Beran; 1Ƥ (allotype) (paratype) 12. July 2007, Germany, Bavaria, Munich, Reitschule [48°09’18” N, 11°35’22” E], 511 m, CDC-light trap, leg. B. Beran.

Derivatio nominis: Dedicated to the grandfather of the senior author, Stephan Beran.

Male description: Head with round eyes, no eyes-bridge, as typical of the subfamily. Antenna 15 segmented (broken in all specimens during preparation, fig 1). Scape short, barrel-shaped, pedicel spherical, shorter than scape. Flagellomeres elongate, slightly asymmetric with a pair of elongate simple ascoids, about 1.3 times longer than a flagellomere. Relative size of basal antennal segments: 28-24-53-46-42- further distal segments missing; scape length 0.1 mm. Palpus 3-segmented (fig 2) 0.24mm long. Basal segment with a circular pit (vesicle), with sensory rods. Relative length of the palpus segments: 29-19-21.

Thorax and legs elongate without specific features. Wing venation is typical of the genus with only a single vein (R4+5) between the forks R2/R3 and M1/M2. It is not clear whether sc terminates into costa or into R1 and what is the cross-vein. Radial fork slightly distal of medial fork, a cross-vein between the stems of M1+2 and M3/CuA1. CuA2 elongate, with basal cross-vein to basal stem of M3/CuA1, anal vein short. Wing length 1.88 mm (holotype); 1.93, 2.04 mm (paratypes); 2.02 mm (allotype).

Male abdomen with tergites 7 and 8 strongly reduced to thin clasps, sternites of usual size. Segment 8 with a torsion of about 90° to segment 7, genitalia with another torsion of 90° to segment 8 so that the genitalia become inverted (fig 5). Genitalia complicatedly structured; gonocoxite basally with an elongate dorsal apodeme (da); distally with a long prominent ventral process, along its inner margin covered with a row of strong bristles; at about middle height lies a short and broad process with several tips and with strong setae. Above it the slightly bent and flattened simple gonostyle articulates. Aedeagus consists of a laterally flattened strongly sclerotized aedeagus apodeme and a distal, slightly sclerotized portion (figs 4, 5, 6). The distal portion maybe bend ventrally at an about median position, where the lateral ‘arms’ of the aedeagus (la in figures 5 and 6) are markedly thinner. In a basal position of the aedeagus broad distal sclerites are visible (fig 5), in a distal position these are merely visible because they are fold up and appear as if one looks at a blade tip (fig 4). At the end of the basal aedeagus apodeme a pair of sperm ducts opens into a wide chamber, flanked by the faint sclerites. Tergite 9 rectangular, cerci are in a horizontal plane, elongate triangular, quite large and setose, best visible in lateral view.

Female description: specimen of similar size and coloration as male, palpus three-segmented, also with a depression and sensory rods on the basal segment. Sternite 8 triangular with a slight basal incision, the tip loosely covered with setae, cerci oval (fig 7). The inner genitalia consist of a broad ventral apodeme, and an elongate slightly sclerotized plate. Above the plate is a thin long apodeme that is probably joined to the plate. Further, two short sperm ducts that evolve from a single opening are visible. They end in a pair of holes with well sclerotized circular entrance. Whether these are openings of spermathecae remains dubious. Further structures cannot be sufficiently interpreted at the moment.

Remarks. Six European species of Trichomyia Haliday, 1839 are known so far: T. urbica Haliday (widespread in Europe), T. parvula Szabó ( Hungaria, Germany, Great Britain) ( Szabó 1960), T. malickyi Wagner ( Greece: Islands of Kefallinia and Euböa; Wagner, 1982, Ježek, 1990), T. kostovi Ježek ( Bulgaria; Ježek 1990), T. carlestolrai Wagner ( Spain: Barcelona; Wagner 2001) and T. minima ( England; Withers 2004). Relations to the already described European species appear minor. The construction of the genitalia, especially the male gonostyli is unique among European taxa.

It is still unknown whether specific relationships between certain tree species and Trichomyiinae do exist. However it is remarkable that the discovery sites of recently described European species are related to old forests and single old trees and remainder of old trees with slowly decaying trees and traditional careful forest management. Thus we speculate that quite a number of European Trichomyiinae still remains undiscovered. We will find them probably in the minor remnants of old forests with slowly decaying trees and in nature reserves.