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<em>Bactrocera aquilonis</em>

Bactrocera aquilonis

Northern Territory fruit fly
Previous scientific names: Strumeta aquilonis May, Dacus (Bactrocera) aquilonis

Diagnosis

Morphological – adult

Features include:

  • medium sized species
  • facial spots present
  • postpronotal lobes and notopleura yellow
  • scutum pale red-brown with fuscous markings
  • mesopleural stripe reaching almost to anterior npl. seta
  • lateral postsutural vittae present
  • medial postsutural vitta absent
  • scutellum yellow
  • wing with a narrow fuscous costal band and broad fuscous anal streak
  • cells bc and c fuscous
  • microtrichia covering cell c and most of cell bc
  • abdominal terga III-V pale orange-brown with pale fuscous along anterior margin of tergum III and widening over lateral margins of that tergum, a medial longitudinal pale fuscous band on terga III to V
  • posterior lobe of male surstylus short
  • female with aculeus tip needle shaped (Drew 1989; pers. comm. Drew 2010).

Morphological – larvae

See White and Elson-Harris 1992 p. 179.

Molecular

DNA barcoding

BOLD reference data available, but cannot be distinguished from B. neohumeralis or B. tryoni.

RPA2 data

B. aquilonis AQL004 Classic morphology RPA2
B. aquilonis AQL006 Abdomen variation RPA2
B. aquilonis AQL007 Abdomen variation RPA2

DDOSTs2 data

B. aquilonis AQL004 Classic morphology DDOSTs2
B. aquilonis AQL007 Abdomen variation DDOSTs2

EIF3L data

B. aquilonis AQL004 Classic specimen EIF3L
B. aquilonis AQL007 Abdomen variation EIF3L
B. aquilonis AQL009 Scutum variation EIF3L
B. aquilonis AQL015 Classic specimen EIF3L

FCOI data

B. aquilonis AQL004 Classic specimen FCOI
B. aquilonis AQL006 Abdomen variation FCOI
B. aquilonis AQL007 Abdomen variation FCOI
B. aquilonis AQL008 Scutum variation FCOI
B. aquilonis AQL009 Scutum variation FCOI
B. aquilonis AQL010 Colour variation FCOI
B. aquilonis AQL011 Classic specimen FCOI
B. aquilonis AQL012 Abdomen variation FCOI
B. aquilonis AQL013 Abdomen variation FCOI
B. aquilonis AQL015 Classic specimen FCOI
B. aquilonis AQL016 Classic specimen FCOI
B. aquilonis AQL017 Classic specimen FCOI
B. aquilonis AQL018 Classic specimen FCOI
B. aquilonis AQL019 Classic specimen FCOI
B. aquilonis AQL020 Classic specimen FCOI
B. aquilonis AQL021 Classic specimen FCOI
B. aquilonis AQL022 Classic specimen FCOI

POP4 data

B. aquilonis AQL004 Classic morphology POP4
B. aquilonis AQL006 Abdomen variation POP4
B. aquilonis AQL007 Abdomen variation POP4
B. aquilonis AQL010 Classic specimen POP4
B. aquilonis AQL011 Classic specimen POP4
B. aquilonis AQL015 Abdomen variation POP4
B. aquilonis AQL017 Classic specimen POP4
B. aquilonis AQL022 Classic specimen POP4

 

 

PCR-RFLP Test 1

BsrI: 600, 200

HinfI: 770

HhaI: 650, 200

Sau3AI: 420

SnaBI: Does not cut

SspI: 570, 180

Vspl: Does not cut

Approximate ITS1 fragment length – gel: 850 bp.

PCR-RFLP Test 2

SspI produces a B. tryoni species complex diagnostic restriction pattern;

SspI: 1000, 550, 100 bp.

This species cannot be distinguished from B. neohumeralis or B. tryoni.

Other restriction patterns useful for diagnosis of the complex are listed in Restriction enzyme haplotype chart, with choice based on relative distinctiveness from other species potentially trapped; descriptions of the patterns are given in Diagnostic restriction patterns.

Cameron et al. 2010 found that there is no genetic evidence supporting the separation of B. aquilonis and B. tryoni as distinct species.

Host Range

Bactrocera aquilonis has been recorded on hosts from a wide range of families. These include: Annonaceae, Arecaceae, Chrysobalanaceae, Combretaceae, Curcurbitaceae, Ebenaceae, Elaeocarpaceae, Euphorbiaceae, Lauraceae, Meliaceae, Myrtaceae, Rosaceae, Rubiaceae, Rutaceae, Santalaceae and Sapotaceae (for a full list of recorded hosts see Smith et al. 1988; Hancock et al. 2000).

Major commercial hosts:

  • Momordica charantia (bitter gourd)
  • Psidium guajava (guava)

Distribution

Oceania

Australia -northern areas of Western Australia and the Northern Territory (Hancock et al. 2000).

Similar species

In the Northern Territory this species dramatically increased its host range during 1985. Since B. aquilonis and B. tryoni will produce viable offspring when crossed in the laboratory (Drew and Lambert 1986), hybridisation with B. tryoni was strongly suspected and might explain this increase (Smith and Chin 1987; Smith et al. 1988). By 1997, most but not all commercial production areas and larger towns supported populations of this fly (i.e. the suspected hybrid), which attacks a wide range of cultivated hosts. Therefore, many of the Northern Territory host records for B. aquilonis since March 1985 are attributed to the suspected hybrid B. aquilonis x B. tryoni and are recorded under B. tryoni and not under B. aquilonis in the above table (Hancock et al. 2000).

Bactrocera aquilonis and B. tryoni are very similar in general body and wing colour patterns. Bactrocera aquilonis differs in being an overall paler colour with the scutum pale red-brown and the abdominal terga generally fulvous without distinct fuscous markings. However, these differences are not easily observed. Also these species can be separated on the differences on the ovipositors: apex of aculeus rounded and spicules with 7-10 uniform dentations in B. tryoni compared with the more pointed aculeus and uneven dentations in B. aquilonis (Drew 1989).

A recent molecular genetic study of north-western Australian fruit fly populations (Cameron et al. 2010) concluded that there is no genetic evidence supporting B. aquilonis as a distinct species from B. tryoni. They conclude that the recent increase in host range of fruit flies in north-western Australia is due to local populations of B. tryoni (= B. aquilonis) utilising additional food resources from increased agricultural production in this region.

Currently, B. aquilonis is regarded as belonging to the B. tryoni species complex which includes B. tryoni, B. neohumeralis and B. melas. It is most similar to B. tryoni, and is difficult to distinguish from paler B. tryoni forms. Further research on the taxonomy of this group is currently being undertaken.

 

Pest Status

  • Australian
  • Minor pest species

Attractant/Lure

Cue lure