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<em>Rhagoletis completa</em>

Rhagoletis completa

Walnut husk fly
Previous scientific names: Rhagoletis suavis completa Cresson, Rhagoletis suavis var. completa Cresson

Diagnosis

Morphological – adult

The four transverse wing bands are present and connected. The thorax of R. completa is orange/pale brown and the abdomen is partly dark brown. The scutellum is concolorous yellow (Foote et al. 1993).

Morphological – larvae

Information not available.

Molecular

DNA barcoding

BOLD reference data available, but not well resolved amongst a number of other species in BOLD.

Low divergence clades may be apparent and used in conjunction with other information about the specimen may be sufficient to make a confident identification

PCR-RFLP Test 1

BsrI: Data not available

HinfI: Data not available

HhaI: Data not available

Sau3AI: Data not available

SnaBI: Data not available

SspI: Data not available

Vspl: Data not available

PCR-RFLP Test 2

AluI is fully diagnostic; DraI, HinfI, RsaI and SspI also have diagnostic value.

AluI: 640, 450, 130, 120, 110

Host Range

Rhagoletis completa has been recorded on hosts from two families, Juglandaceae (Juglans spp. are predominant hosts) and Rosaceae (sub-optimal hosts, e.g., peaches) (for a full list of recorded hosts see CABI 2007).

Major commercial hosts:

  • Juglans californica (California walnut)
  • Juglans hindsii (Californian black walnut)
  • Juglans nigra (black walnut)
  • Juglans regia (walnut)

Distribution

Southern and Central USA including northern Mexico; adventive in Western USA since the 1920s. Also established in Southern Europe since the early 1990s (CABI 2007). It is widely distributed over Central and Western mainland USA (pers. comm. Drew 2010), but this species is absent from several states; the map as presented does not represent true geographic distributions within the USA.

Similar species

Rhagoletis completa is an unusual economic tephritid species in that it is a major pest of walnuts, in contrast to the soft fleshy fruit hosts of other fruit fly species. It is best diagnosed by the distinctive wing colour patterns and a red-brown thorax. Rhagoletis completa is similar to R. berberis; however, the thorax and abdomen of R. completa are golden yellow (completely black in R. berbeis) and the scutellum is concolorous yellow (black with a distinct yellow spot in R. berberis). This species may also be confused with R. suavis.

Pest Status

  • Exotic

Attractant/Lure

No known record, but can be captured in traps emitting ammonia.