Trichonta pulchra Gagné, 1981

Chandler, Peter J., 2009, The fungus gnats (Diptera: Bolitophilidae, Keroplatidae, Mycetophilidae) of Sardinia, with description of six new species *, Zootaxa 2318 : -

98. Trichonta pulchra Gagné, 1981 **

( Figs 15–18)

Material examined. S1 19.IX–3.X.06 2 ♂♂ 1 ♀, 3-17.X.06 10 ♂♂ 1 ♀, 17-31.X.06 3 ♂♂.

Description. This species is redescribed here, on the basis of the Sardinian specimens, to amplify the brief original description and in view of points of difference from it, as explained in the notes.

Male. Head dark brown with dark bristling. Antenna about 1.5 times as long as thorax, with scape, pedicel and base of first flagellomere yellow, otherwise brownish; flagellomeres about twice as long as broad. Palpus yellowish, slender.

Thorax dark brown except for large yellow humeral patches separated by broad dark brown stripe reaching fore margin; short dark bristling on mesonotum; scutellum with two pairs of long marginal setae, more than twice its length. Pleura bare except for a few short setae on upper part of anepisternum, laterotergite with setae on disc and metepisternum with short weak setae on posterior margin. Mediotergite bare. Wing clear with slight brownish shade on membrane from costa to radial sector. Vein Sc ending free about 0.5 distance to base of Rs. Costa ending at tip of R 5. Rs short and vertical, r-m a little longer but shorter than stem of median fork. Posterior fork beginning at level of middle of stem of median fork. Vein A 1 weak, reaching level of base of posterior fork. Radial veins and fork veins (except their bases) setose, other veins including Rs, r-m, tb, stems of fork veins and vein A 1 are bare. Haltere yellow. Wing length 2.4–2.7 mm. Legs yellow except tip of hind coxa and apical quarter of hind femur which are dark brown; all setulae dark; hind coxa without a basal seta. Mid tibia with 3 posterodorsal setae less than tibial width in length. Hind tibia with 10–11 anterodorsal and 7 dorsal setae, about half tibial width in length. Fore metatarsus half length of its tibia. Tibial spurs brown, 1:2:2, fore as long, mid 1.5 times and hind twice as long as width of tibial apex.

Abdomen dark brown with tergites 1–4 partly yellow, 1 mainly yellow and dark on midline, 2–4 with yellow basal patches narrowed dorsally, sometimes more extensive and only narrowly dark dorsally, remaining tergites entirely brown; with short dark bristling. Genitalia ( Figs 15–18) dark brown; gonocoxites with narrow median excavation ventrally; gonostylus with ventral part shallowly bilobed, a simple bristly mesal lobe, a short dorsal lobe with strong apical setae and two large internal lobes bearing combs of corrugations. Aedeagus ( Fig. 17) short and broad. Tergite 9 ( Fig. 18) short and broad; cerci a little more elongate, together shorter than gonocoxites.

Female. Similar to male. Abdomen with bases of tergites 2–5 narrowly yellow, interrupted on midline on 3–4, no more than a third of length and not broadened laterally, very narrow on 5. Ovipositor brown, with short cerci. Wing length of female 2.5 mm.

Chorotype. Type 1 [1.01 of Vigna Taglianti et al. (1999)]. Holarctic.

Italian distribution. Sardinia only.

Notes. Trichonta pulchra was described from one male from Canada and four British males, the latter being in the author’s collection and these having posterior setae on the hind tibia, although some more recent British material has these setae sparse or absent. It has only otherwise been recorded from the Czech Republic ( Ševčík 2001) and Hungary ( Ševčík & Papp 2002). Because they lack posterior setae on the hind tibia the Sardinian specimens run to couplet 57 in the key by Gagné (1981), where they agree with T. vitta ( Meigen, 1830) in having Sc ending free but have the dorsal part of the gonostylus short. The specimens are also described and figured here because fig. 119 of Gagné (1981) shows the gonocoxites as having a simple margin and it is not apparent that this species has a medial excavation of the gonocoxites resembling that in T. patens Johannsen, 1912 . However, all parts of the gonostylus differ in structure from that species.