Dacus dorsalis

Description

Bactrocera dorsalis, previously known as Dacus dorsalis and commonly referred to as the oriental fruit fly, is a species of tephritid fruit fly that is endemic to Southeast Asia. It is one of the major pest species in the genus Bactrocera with a broad host range of cultivated and wild fruits. Male B. dorsalis respond strongly to methyl eugenol, which is used to monitor and estimate populations, as well as to annihilate males as a form of pest control. They are also important pollinators and visitors of wild orchids, Bulbophyllum cheiri and Bulbophyllum vinaceum in Southeast Asia, which lure the flies using methyl eugenol. The fly is similar to the closely related species B. carambolae and B. occipitalis. The species name B. dorsalis is identical to other synonyms B. papayae, B. invadens and B. philippinensis. B. dorsalis is a species of tephritid fruit fly. Flies that belong to this family are usually small to medium-sized with colorful markings. In particular, B. dorsalis belongs to a complex of physically similar flies called the Bactrocera dorsalis complex, whose defining characteristics include a mostly black thorax and dark T-shaped marking on the fly's abdominal segment. The T-shape marking consists of a dark medial and transverse band along the fly's abdomen. The B. dorsalis species has distinctive yellow and black markings on its thorax and abdomen, which may vary between flies. Two vertical yellow markings on the thorax and the dark T-shaped marking on the abdomen differentiate this species of fly from its close relatives. The wings are clear with a continuous costal band. The adult body is around 8.0 mm in length, with wings approximately 7.3 mm in length. The female adult has a tapered ovipositor for depositing eggs in host fruits, while in male adults this ovipositor is notably absent. Endemic to Southeast Asia, B. dorsalis is a highly invasive pest species that now has a presence in at least 65 countries. It has also been introduced to Hawaii, the Mariana Islands, and Tahiti. The fly is also found in most countries of sub-Saharan Africa. From 1910 to 1990, the fly species was only observed in 5 countries; however, in the last three decades, the rate of spread by B. dorsalis has sharply increased, with the species invading an additional 70 countries.