head with 1 pair of proclinate and 1 or 2 pairs of reclinate orbital bristles
post-vertical bristles, when present, parallel or convergent
arista usually branched above and below
mesopleuron bare
costa twice broken
auxiliary vein not reaching costal margin (Bock 1976).
Sophophora species are characterised by relatively narrow cheeks and possession (in most species) on the abdominal tergites of dark posterior bands that are not interrupted in the mid-line (Bock 1980).
SWD has a uniform apricot coloured thorax that is free of stripes, spots or patterns, with unbroken dorsal bands on its abdomen (Blacket et al. 2015 b).
Male SWD have a single apical wing spot and a single row of apical dark combs running across (rather than parallel with) each of the basal two tarsal segments.
Female SWD possess an ovipositor that is strongly sclerotized with robust teeth (typically with 30-36 teeth, Seljak 2013), very strongly developed along the lower half towards the ovipositor tip with a saw-like lower edge, the ovipositor is 6-7 times longer than the diameter of the spermatheca (only 2-3 times longer in most other Drosophila species) (Hauser 2011).
Refer to diagnostic resource ‘PM 7/115 (1) Drosophila suzukii’ (Bulletin OEPP/EPPO Bulletin (2013) 43 (3), 417–424) for any suspect detections of SWD.
Morphological – larvae
Not available/included in this edition.
Molecular
DNA barcoding
BOLD reference data is available.
Published molecular tests
DNA barcoding has been employed by to confirm SWD in Europe (Calabria et al. 2012).
Drosophila suzukii - Male Wing. Image: courtesy of Mark Blacket
Host Range
Spotted Wing Drosophila (SWD), is one of the few species of Drosophilidae known to be a pest of healthy, unripe fruit (Walsh et al. 2011, Atallah et al. 2014), Drosophila generally prefer to breed in fruit that is already decaying and fermenting.
SWD is a highly polyphagous pest that breeds in a wide variety of mostly thin skinned small fruits (particularly Rosaceae) and is currently known from fifteen plant families (Cini et al. 2012):
Actinidiaceae
Adoxaceae
Caprifoliaceae
Cornaceae
Ebenaceae
Elaeagnaceae
Ericaceae
Grossulariaceae
Moraceae
Myricaceae
Myrtaceae
Rhamnaceae
Rosaceae
Rutaceae
Vitaceae.
Major commercial hosts:
Prunus species (cherries & stone fruit)
Fragaria ananassa (strawberry)
Rubus species (berries)
Vitis species (grapes)
Malus species (apples)
Pyrus species (pears)
Distribution
SWD has recently and rapidly spread from eastern Asia to many other regions of the world (Walsh et al. 2011), including parts of North America, Europe and South America.
SWD is currently unknown from Australia.
Similar species
A large number of Drosophila species are known from Australia and many Drosophila species have larvae that are commonly found in rotting fruit.
SWD belong to the Sophophora subgenus of Drosophila, a group that contains a large number of species (>300 worldwide), including the common cosmopolitan D. melanogaster and D. simulans. There are twenty species currently known from Australia (Atlas of Living Australia).
Male D. melanogaster and D. simulans are superficially similar to SWD in usually possessing dark tipped abdomens, but they differ in the morphology of the combs on their basal tarsal segments and in having non-spotted wings (Blacket et al. 2015 b).
Female D. immigrans are superficially similar in the morphology of the ovipositor, however the relative size of the ovipositor compared with the spermatheca differs substantially between these two species, and in SWD the ovipositor is strongly sclerotized with robust teeth very strongly developed along the lower half towards the ovipositor tip (Hauser 2011).
Pest Status
Exotic
High level, highly invasive, pest species of a large number of soft fruits
Attractant/Lure
Adults are known to be attracted to traps baited with a combination of wine, vinegar and soap (Landolt et al. 2012)
