Description of Potophila verrucosa, gen. n. et sp. n. (Diptera: Psychodidae: Psychodinae) from the West Usambara Mountains, Tanzania

ABSTRACT Potophila verrucosa gen. n. et sp. n. is described based on a male from the West Usambara mountains, Tanzania. The genus and species are characterised by an elongate first flagellomere with the node more than three times as long as the internode, an asymmetrical aedeagus and two parameres carrying rugose morphoventral appendages. Potophila verrucosa cannot be placed in a systematic context with certainty, but several characters are consistent with a relationship to the tribe Psychodini.


INTRODUCTION
The Psychodid fauna of Africa is still poorly known. In the catalogue by Kvifte (2012), 174 described species in 27 genera are listed; however, large parts of the continent remain species, and often also genera not previously recorded from Africa (Wagner & Andersen The Eastern Arc mountain chain in Tanzania and Kenya forms one of the most important global hotspots of biodiversity conservation due to its high levels of endemicity (Burgess et al. 2007). Very little is known of the Psychodidae from this ecoregion; a total of 18 species are known from the Ulunguru area near Morogoro and from the West Usambara mountains (Duckhouse 1987;Wagner & Andersen 2007). In the present paper, one further species is described based on a specimen collected in the West Usambara 176 species in 29 genera.

MATERIAL AND METHODS
The specimen was collected using a sweep net during the Zoological Museum of Bergen's (ZMB) 1990 expedition to the West Usambara mountains (see Wagner & Andersen 2007). Prior to examination, it was macerated in KOH and mounted in Canada balsam. The specimen is kept in the natural history collections at the University Museum of Bergen.
All measurements are in micrometres (μm), except wing length, which is given in millimetres (mm). Measurements are given with an accuracy of 3 μm, except wing length, which is given with an accuracy of 0.03 mm.
Morphological terminology is according to Quate and Brown (2004), with the following exceptions: the surstyli (often wrongly referred to as cercopodia or cerci) are called "epandrial claspers" following Santos and Curler (2014), and the gonocoxal apodemes are called "gonocoxal condyles" to more accurately describe their morphology. TAXONOMY Potophila gen. n. Etymology: From Greek , "drinking-bout", and , "friend", the new genus is feminine.
Wing (Fig. 1B): 3.135 mm long × 1.26 mm wide; ovoid; basal costal node enlarged; membrane unpatterned, without vestiture; Sc terminating blind in the wing, reaching origin of R 5 ; R 2+3 not connected to R 4 ; radial fork in distal half of the wing, medial fork in basal half; basal part of M 2 weakened; r-m and m-cu faint; R 5 terminating slightly below apex of wing; CuA 2 terminating slightly distally to middle of wing but basal to radial fork; bases of M 1+2 and CuA 2 expanded; basal cells terminating close to base of wing.
Abdomen without special features.

DISCUSSION
Potophila verrucosa cannot easily be placed systematically within Psychodinae, both because of its enigmatic morphology and the poor preservation of the specimen. and the palps are not available for examination. Still, some speculations can be made based on the available evidence.
The head characters of Potophila lack any unambiguous phylogenetic signals.
The genitalia of Potophila verrucosa consist of a slightly asymmetrical elongate ae dea gus with two parameres, the aedeagus being twisted 90° to the left. Paired parameres that are symmetrical or asymmetrical are likely to be part of the ground-plan for Psychodinae (cf. Vaillant 1982). Twisted aedeagi are present in several Psychodini taxa such as Trichopsychoda Tonnoir, Threticus Eaton and Psychoda Latreille, as well as in two species of Brunettiina (Wagner & Vaillant 1983) and in the currently unplaced taxa Saximormia Bryopharsos Quate. A uniseriate distal row of tenacula is present in Psychodini and most Maruinini/Setomimini, but also in Brunettiina and in the Pericomaini genera Berdeniella Vaillant and Szaboiella Vaillant.
Overall, the characters of Potophila are consistent with a placement near or within Psychodini (in the sense of Quate (1959) and Duckhouse (1985)); and the shape of the Threticus. This must, however, be