Brachyradia asiatica, 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

Brachyradia asiatica , new species

( Figs. 1A, D , 2A, B, G , 3A–D )

Type material. — Holotype male: THAILAND, Chiang Mai, Doi Suthep NP, 31 Oct.2004, No. 11, along a forest brook, coll. L. Papp & M. Földvári ( HNHM, pinned).

Paratypes: 1 male: THAILAND, Nakhon Ratchasima, Khao Yai NP, evergreen forest near Tiger Trail , 14°27.511'N, 101°22.408'E, 760 m, Malaise trap, 19–26 Jun.2007, coll. Pong Sandao, T2229 (in QSBG) ; 1 male, 1 female: Kamphaeng Phet, Mae Wong NP, Chong Yen , 16°5.968'N, 99°6.472'E, 1306 m, Malaise trap, 3–10 Sep.2007, coll. Chumpol Piluk & Aram Inpuang, T2812 ( JSOC) ; 1 male: Prachuab Khiri Khan, Khao Sam Roi Yot NP, Nursery , 12°7.58'N, 99°57.478'E, Malaise trap, 6–13 Jul.2008, coll. Amnad & Yai, T3035 ( QSBG) ; 2 males, 1 female: Chiang Mai, Doi Chiang Dao NP, Nature trail, 19°24.278'N, 98°55.311'E, 491 m, Malaise trap, 10–24 Mar.2008, coll. Songkran & Apichart, T3155 , T3156 ( MZLU [-JKJ-SPM-058443-45, all on slides]) ; 2 males, 4 females: MALAYSIA, Selangor, Ulu Gombak, University of Malaya Field Study Centre , 800 ft, Malaise trap, 22 Feb. – 21 Mar.1997, coll. H. Hippa, M. Jaschhof & B. Viklund ( NHRS) ; 1 male: INDONESIA, South Sulawesi, Tana Toraja, Rantepao , 21–23 Jan.2010, Malaise trap, coll. J. Šev ík ( JSOC) .

Diagnosis. — On average, slightly larger than B. australis , with darker abdominal tergites. Distinct diagnostic characters are found in the detailed shape of the terminalia. In lateral view the male gonostylus ( Fig. 3B ) has straight dorsal branch, curved ventral branch, and dilated but not distinctly T-shaped medial branch; the hypandrial lobe ( Fig. 3A ) is small; and the cerci ( Fig. 3C ) are rectangular. The female terminalia ( Fig. 3D ) have rounded posterior margin of tergite VI.

Etymology. — The specific name refers to the occurrence of this species in Asia.

Description. — Male: Body length 2.6–3.0 mm. Wing length 1.95–2.08 mm. Colouration overall brownish yellow. Head, all antennal segments, mouthparts and palpi yellowish. Scutum and pleurites uniform yellowish brown, halter brownish yellow. Wings hyaline, membrane unmarked. Legs all yellowish. Abdomen yellowish with brown markings; tergites I–IV with a dark posterior triangular marking, tergite IV darkened also laterally, tergite V all blackish brown, tergites VI–VIII mostly brown. All tergites and sternites covered with pale setae. Terminalia yellowish brown, ventral lobes of gonostylus sclerotized, blackish brown. Terminalia ( Figs. 2G , 3A–C ) with proctiger narrowly connected to the reduced tergite IX, enlarged with distinct pointed epiproct and large internal hypoproct with pointed, downcurved apex. Cerci long rectangular, with angular corners apically. Gonocoxite with small bulbous hypandrial lobe; aedeagal guides large, rounded, retracted into gonocoxite. Aedeagal apparatus with sclerotized apodeme connecting to conocoxite. Gonostylus ( Fig. 3B ) with five distinct branches; dorsal branch long rectangular, setose on outer surface, inner surface with some setae ventrally and apically; dorsointernal branch bulbous, sclerotized, with a few strong setae medially and a strong bristle subapically; medial branch elongated, sclerotized, apically moderately dilated, devoid of setae; ventral branch long narrow, rectangular in ventral view, gently curved in lateral view, with setae scattered on basal half, one small stiff seta apically; internal branch long subtriangular, with pair of strong setae apically; anterior branch vestigial or absent.

Female: Body length 2.4–2.5 mm. Wing length 1.65–1.95 mm. Colouration similar to male. Terminalia ( Fig. 3D ) short oviscapt, with tergite VII and IIX deeply retracted into segment VI. Tergite VI widely but shallowly excavated dorsally, forming rounded, weakly crenulated posterior margin, marginal setae long. Cercus 2 narrow ovate, without constricted base. Gonocoxite VIII with two apical bristles much stronger than the rest. Gonapophysis VIII narrow, hyaline.

Variation. — We found a certain variation in the length of the M-petiole (even between left and right wing of same specimen) that sometimes makes the point of furcation of M opposite to that of Cu-fork, sometimes distinctly before it.

Biology. — Unknown

Figures

Fig. 1. Morphology of adult Brachyradia, new genus. Photos of whole (moderately bleached) specimens in alcohol (A, B) and cleared and slide-mounted parts (C–F). (A) Habitus of B. asiatica, new species; (B) habitus of B. australis, new species; (C) thorax with coxae of B. australis, new species, enlarged in lateral view. The shape of anepisternum and propleurites is enhanced. (D) Wing of male B. asiatica, new species; (E) wing of large female B. australis, new species; (F) wing of small male B. australis, new species. Abbreviations: A1 = anterior anal vein; A2 = posterior anal vein; anepist = anepisternum; aprnt = antepronotum; C = costa; CuA1 and CuA2 = anterior branch of cubitus; CuP = posterior branch of cubitus; cx 1 = forecoxa; cx 2 = midcoxa; cx 3 = hindcoxa; dmp = distal median plate; h = humeral; hlt = halter; ltg = laterotergite; M-pet = petiole of media; M1 and M2 = branches of media; mtg = mediotergite; mtepst = metepisternum; proepist = proepisternum; R1 = anterior branch of radius; R4+5 = posterior branch of radius; Rs = radial sector; sc = subcosta; sctl = scutellum; ta = anterior transversal (= crossvein rm); tb = basal transversal.

Fig. 2. Morphology of adult Brachyradia, new genus. Photos (A–F) and illustrations (G–H) of cleared and slide-mounted parts. (A) Head of B. asiatica, new species, in dorsal view with antennae removed; (B) ditto with whole antennae and palps; (C) head of B. australis, new species, in lateral view; (D) palp segment III–IV of B. australis, new species, enlarged in dorsal view; (E) palp segment III–V of B. australis, new species, enlarged in lateral view; (F) antennae of B. australis, new species, enlarged in lateral view; (G) internal organs of male terminalia of B. asiatica, new species, lateral view with gonostyles removed; (H) internal organs of male terminalia of B. australis, new species, caudal view with gonostyles removed. Abbreviations: aed gd = aedeagal guide; aed = aedeagal apparatus; cerc = cercus; clyp = clypeus; epi = epiproct; fc = face; flag = flagellum; fr fur = frontal furrow; fr tub = frontal tubercle; gc ap = gonocoxal apodeme; gc II = section II of gonocoxite; gc III = section III of gonocoxite; hyp pr = hypoproct; hyp lb = hypandrial lobe; l oc = lateral ocellus; par = paramere; par ap = parameral apodeme; sens pit = sensory pit; tg IX = tergite IX; vrt = vertex.

Fig. 3. Terminalia of Brachyradia asiatica, new species: (A) male terminalia in ventral view; (B) gonostylus in internal view; (C) tergite IX, proctiger and cerci in dorsal view; (D) female terminalia in lateral view. Scale bar = 0.1 mm. Abbreviations: d br = dorsal branch of gonostylus; di br = dorsointernal branch of gonostylus; hyp lb = hypandrial lobe; i br = internal branch of gonostylus; m br = medial branch of gonostylus; v br = ventral branch of gonostylus.