Bactrocera (Zeugodacus) tau (Walker)

Drew, R. A. I., Romig, M. C. & Dorji, C., 2007, Records Of Dacine Fruit Flies And New Species Of Dacus (Diptera: Tephritidae) In Bhutan, Raffles Bulletin of Zoology 55 (1), pp. 1-21 : 12

Bactrocera (Zeugodacus) tau (Walker)

Dasyneura tau Walker, 1849: 1074 .

Dacus hageni de Meijere, 1911: 375 , type locality, Sumatra.

Dacus caudatus var. nubilus Hendel, 1912: 16 , type locality Taiwan.

Dacus nubilus ssp. femoralis Hendel, 1934: 11 , type locality China.

Dacus (Zeugodacus) tau – Hardy, 1977: 60.

Bactrocera (Zeugodacus) tau – Liang et al., 1993: 138; Wang, 1996: 72; Norrbom et al., 1998: 104.

Material examined. – BHUTAN: 9 males (10 May.2000) , 8 males (17 May.2000), 4 males (24 May.2000), 5 males (31 May.2000), 4 males (21 Jun.2000), 8 males (23 Jul.2000), 7 males (10 Aug.2000), 6 males (16 Aug.2000), 17 males (30 Aug.2000), 23 males (6 Sep.2000), 18 males (12 Sep.2000), 25 males (20 Sep.2000), 21 males (27 Sep.2000), 18 males (5 Oct.2000), 8 males (18 Oct.2000), 7 males (16 Nov.2000), Rimchu trap No. 1, coll. C. Dorji ; 3 males (7 Jun.2000), 1 male (28 Jun.2000), 6 males (19 Jul.2000), Rimchu trap No. 1, coll. C. Dorji et al .; 5 males, Rimchu trap No. 1, 4 May.2000, coll. B.S. Fletcher ; 4 males, Rimchu trap No. 1, 14 Jun.2000, coll. Nado ; 1 male, Rimchu trap No. 1, 21 Jun.2000, coll. Nado et al .; 2 males, Rimchu trap No. 2, 10 May.2000, coll. B.S. Fletcher ; 1 male, Rimchu trap No. 3, 10 May.2000, coll. B.S. Fletcher ; 7 males (10 May.2002), 4 males (17 May.2002), 1 male (24 May.2002), Rimchu , coll. C. Dorji ; 2 males, Rimchu , 26 Apr.2000, coll. Clarke & Fletcher ; 6 males, Phuentsholing , 6 May.2000 ; 6 males (17 Jul.2000), 6 males (31 Jul.2000), 6 males (7 Aug.2000), 2 males (2 Oct.2000), 2 males (23 Oct.2000), Tsirang; 5 males (19 Jun.2000) , 11 males (10 Jul.2000) , Tsirang, coll. T.D. & S.D .; 4 males, Tsirang ( Damphu orchard), 20 Apr.2000 ; 6 males, Suntalay , 28 Jun.2000, coll. S. Wangdi ; 9 males, Lingmethang 11 km, 9 Jun.2001, coll. Brian Fletcher. All specimens attracted to cue lure. Specimens in NPPC and QDPI .

Diagnosis. – A medium sized species; face fulvous with a pair of medium sized circular to oval black spots; postpronotal lobes and notopleura yellow; scutum black with large areas of red-brown centrally and anterocentrally; lateral and medial postsutural vittae present; yellow spot anterior to mesonotal suture in front of lateral postsutural vittae; mesopleural stripe reaching midway between anterior margin of notopleuron and anterior npl. seta; scutellum entirely yellow; wing with a narrow dark fuscous costal band overlapping R 2+3 and expanding into a distinct apical spot and broad dark fuscous cubital streak; cells bc and c colourless; microtrichia in outer corner of cell c only; abdominal terga III-V fulvous with a black ‘T’ pattern and anterolateral corners of terga IV and V with broad black markings.

Attractant. – Cue lure.

Distribution – Widespread across south and southeast Asia. New record for Bhutan.

Hosts – Recorded from nine plant families and specialising in species of the Family Cucurbitaceae .

Remarks. – Bactrocera (Zeugodacus) tau (Walker) is a very common species throughout southeast Asia. It is an economic pest species, mainly in cucurbit crops, but can be misidentified as it belongs to a complex of closely related species. It is best distinguished by the following characters – scutum black with large areas of red-brown, costal band expanded into a distinct spot at apex, supernumerary lobe in male wing large and keel shaped, abdominal terga III-V fulvous with a black ‘T’ pattern and lateral margins of terga IV and V with either anterolateral corners dark or with lateral longitudinal dark bands over both terga.