Bactrocera (Bactrocera) dorsalis (Hendel)

Dacus dorsalis Hendel, 1912: 18 . Lectotype in NHM.

Dacus (Strumeta) dorsalis — Hardy & Adachi, 1956: 7.

Strumeta dorsalis — Hering, 1956: 63.

Dacus (Bactrocera) dorsalis — Hardy, 1977: 49.

Bactrocera (Bactrocera) dorsalis — Drew & Hancock, 1994: 17, Lectotype designation; Norrbom et al., 1998: 90; Drew & Romig, 2013: 76.

See Drew & Romig (2013) for comprehensive list of synonyms.

Common Name: Oriental Fruit Fly.

Definition: Face fulvous with a pair of medium-sized circular black spots; postpronotal lobes and notopleura yellow; scutum black with areas of red-brown to brown around lateral margins and notopleural suture; broad parallelsided lateral postsutural yellow vittae ending behind ia. seta; medial postsutural yellow vitta absent; anepisternal stripe reaching midway between anterior margin of notopleuron and anterior npl. seta dorsally; scutellum yellow; legs with femora entirely fulvous, fore tibiae fuscous, mid tibiae fulvous, hind tibiae dark fuscous; wing with cells bc and c colourless, microtrichia in outer corner of cell c only; a narrow fuscous costal band confluent with R 2+3 and remaining narrow around apex of wing (occasionally with a slight swelling around apex of R 4+5), a narrow fuscous anal streak, supernumerary lobe of medium development; abdominal tera III-V normally fulvous with a black ‘T’ pattern consisting of a narrow transverse band across anterior margin of tergum III and a narrow medial longitudinal band over all three terga, narrow fuscous to dark fuscous anterolateral corners on terga IV and V, ceromata on tergum V orange-brown to pale fuscous, abdominal sterna dark fuscous.

Distribution: Widespread across South-East Asia from Myanmar eastwards and introduced into the Hawaiian Islands, the Mariana Islands and Tahiti. It appears to be allopatric or parapatric with B. invadens to the west and B. papayae to the south.

Hosts: B. dorsalis is a major economic pest with a wide host range; see Allwood et al. (1999) for host records.

Attractant: Methyl eugenol.

Comments: Bactrocera dorsalis is similar to the pest species B. carambolae and B. papayae in possessing broad parallel-sided lateral postsutural yellow vittae, the costal band confluent with or slightly overlapping R 2+3, femora mostly or entirely fulvous and abdominal terga III-V with a general black ‘T’ pattern. It differs from B. carambolae in possessing a very narrow apical section of the costal band, a narrow medial longitudinal black band on abdominal terga III-V and triangular-shaped anterolateral dark corners on terga IV and V. It differs from B. papayae in having a short male aedeagus and female ovipositor (see key to species below).

Bactrocera dorsalis was the first of the dorsalis complex pest species to be described, with the type locality being Taiwan (Koshun). The main population appears to be concentrated around Southern and Southwestern China, Taiwan, Northern Thailand and Northern Vietnam (see Drew & Romig (2013) for details on distribution). Based on molecular studies, B. dorsalis from Taiwan has been proven significantly different from B. carambolae, B. invadens and B. occipitalis (Drew & Romig, 2013) . Genetic-based studies on the dorsalis complex should always include specimens from the type locality.