Brachyradia australis, ík & Kjaerandsen, 2012

ík, Jan ev & Kjaerandsen, Jostein, 2012, Brachyradia, A New Genus Of The Tribe Exechiini (Diptera: Mycetophilidae) From The Oriental And Australasian Regions, Raffles Bulletin of Zoology 60 (1), pp. 117-127 : 121-124

publication ID	https://doi.org/ 10.5281/zenodo.5347102
persistent identifier	https://treatment.plazi.org/id/AE078780-4C05-FF96-C28A-F979FB90FF61
treatment provided by	Tatiana
scientific name	Brachyradia australis
status	sp. nov.

Treatment

Brachyradia australis View in CoL , new species

( Figs. 1B, C, E, F View Fig , 2C–F, H View Fig , 4A–D View Fig )

Type material. — Holotype male: PAPUA NEW GUINEA, SE, Mamai Pltn., E of Port Glasgow , 150 m, 16 Feb.1965, coll. R. Straatman, light trap ( BMHC, pinned).

Paratypes: 1 male: INDONESIA, South Sulawesi, Tana Toraja, Tilangga , 10 km S of Rantepao, 970 m, 23 Jan.2010, J. Šev ík leg. ( JSOC) ; 18 males, 3 females: PAPUA NEW GUINEA, Madang Province, Halopa village , 600 m, primary rain forest, Oct. – Nov .

2000, coll. L. í ek, Malaise trap ( SMOC, JSOC and MZLU [- JKJ-SPM-058446-51, these 4 males and 2 females mounted on slides]) .

Diagnosis. — On average slightly smaller than B. asiatica , with paler abdominal tergites. Distinct diagnostic characters are found in the detailed shape of the terminalia. In lateral view the male gonostylus ( Fig. 4B View Fig ) has curved dorsal branch, straight ventral branch, and distinctly T-shaped medial branch; the hypandrial lobe ( Fig. 4A View Fig ) is large; and the cerci ( Fig. 4C View Fig ) are long digitiform. The female terminalia ( Fig. 4D View Fig ) have straight posterior margin of tergite VI.

Etymology. — The specific name australis means “southern” in Latin and refers to the occurrence of this species in the southern hemisphere.

Description. — Male: Body length 2.0– 2.5 mm. Wing length 1.32–1.7 mm. Colouration overall brownish yellow and as in B. asiatica , except abdominal tergite V yellowish laterally and tergites VI–VIII mostly yellowish. Terminalia ( Figs. 2H View Fig , 4A–C View Fig ) with proctiger narrowly connected to the reduced tergite IX, less enlarged with retracted epiproct, large internal hypoproct very hyaline centrally ( Fig. 2H View Fig ), with rounded apex and downcurved digitate process. Cerci long slender, with round corners apically. Gonocoxite with large bulbous hypandrial lobe; aedeagal guides small, retracted into gonocoxite. Aedeagal apparatus with weakly sclerotized apodeme connecting to conocoxite. Gonostylus ( Fig. 4B View Fig ) with five distinct branches; dorsal branch long, narrow bladeshaped, sigmoid in lateral view, setose on outer surface, inner surface with rather few setae; dorsointernal branch bulbous, sclerotized, with pair of strong setae apically and a strong bristle subapically; medial branch elongated, sclerotized, apically distinctly dilated into a T-shape with acute corners, devoid of setae; ventral branch long narrow, gently incurved with spoon-shaped apical half in ventral view, straight in lateral view, with scattered setae on basal half, devoid of seta apically; internal branch short subquadrangular, with pair of strong setae apically; anterior branch vestigial or absent.

Female: Body length 2.3–3.0 mm. Wing length 1.50–1.90 mm. Colouration similar to male. Terminalia ( Fig. 4D View Fig ) short oviscapt, with tergite VII and IIX deeply retracted into segment VI. Tergite VI short, with straight posterior margin; marginal setae short. Cercus 2 ovate, with constricted base. Gonocoxite VIII with three apical bristles somewhat stronger than the rest. Gonapophysis VIII broad, hyaline.

Variation. — In this species we found even more variation in proportions of their wing venation ( Fig. 1E–F View Fig ): The Mpetiole varies between 0.8 and 2.5 times as long as crossvein ta, that again sometimes makes the point of furcation of M opposite to that of Cu-fork, sometimes distinctly before it. Small specimens ( Fig. 1F View Fig ) tend to have longer M-petiole accompanied by vein R 1 being proportionally shorter, costa produced proportionally longer beyond R 4+5, and vein M 2 proportionally more shortened. This variation does not appear to be associated with sexes or locality.

Biology. — Unknown