1.Introduction

The Oriental fruit fly, Bactrocera dorsalis (Hendel, 1912), is a member of the Tephritidae (fruit flies) family. Although its' name does not illicit much response here in Singapore, in countries such as the United States and Kenya, the mention of the Oriental fruit fly will send agricultural farmers, fruit vendors, immigration authorities fuming mad. Native to tropical Asian countries like Singapore, this species has since established populations in over 90 countries around the world, causing massive damage to over 400 types of fruit and other crops wherever they are found. Read on to find out more about this notorious species!

Figure 1: Oriental fruit flies on a fruit. Photo credits: Florida Division of Plant Industry

“Oriental fruit fly (Bactrocera dorsalis) (Hendel, 1912)”, by Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.org. URL: http://www.invasive.org (accessed on 15 Nov 2016).

The Tephritidae family comprises non-fruit feeding tephritids, which are rarely pestiferous

Headrick, D. H. & R. D. Goeden, 1998. The biology of nonfrugivorous tephritid fruit flies. Annual Review of Entomology, 43: 217-241.

, and frugivorous tephritids, which contain several genera which are of major economic concern globally

White, I. M. & M. M. Elson-Harris, 1992. Fruit flies of economic significance: their identification and bionomics. C.A.B International in association with ACIAR, Wallingford, Oxon.

. Some notorious fruigivorous tephritid species include: the Mediterranean fruit fly or Medfly (Ceratitis capitata (Wiedemann)), the Cherry fruit fly (Rhagoletis cingulata (Loew)), the Mexican fruit fly, (Anastrepha ludens (Loew)) and the Oriental fruit fly (Bactrocera dorsalis (Hendel)).


The Oriental fruit fly belongs to the Bactrocera dorsalis species complex, a group of almost 100 morphologically similar tephritid taxa

Drew R. A. I. & D. L. Hancock, 1994. The Bactrocera dorsalis complex of fruit flies in Asia. Bulletin of Entomological Research (Suppl. 2), CAB International, Wallingford, UK.

Drew, R.A.I.& M.C. Romig, 2013. Tropical fruit flies of South-east Asia. CAB International, Wallingford, UK.

. Amongst the generally inconspicuous species in this species complex, the Oriental fruit fly and the Carambola fruit fly (B. carambolae) stand out in their economic impact. These species have been recognised as possibly the world’s most important pests of horticulture

Clarke, A.R., Armstrong, K.F., Carmichael, A.E. et al., 2005. Invasive phytophagous pests arising through a recent tropical evolutionary radiation: the Bactrocera dorsalis complex of fruit flies. Annual Review of Entomology, 50: 293–319.

. This page focuses solely on the Oriental fruit fly.

Due to fairly recent updates to the scientific nomenclature of the Oriental fruit fly, information with regards to the Oriental fruit fly can also be found online under the following names: the Asian Papaya fruit fly (Bactrocera papayae), the Philippine fruit fly (Bactrocera philippinensis) and the Invasive fruit fly (Bactrocera invadens). For more information with regards to the many names of this species, head over to the Scientific Name & Synonyms section.



1.1. Disclaimer: Fruit fly ≠ Drosophila melanogaster

Whenever the phrase "fruit fly" is mentioned, the image of the model organism, Drosophila melanogaster, comes to mind. However, albeit their similar common names, Drosophila melanogaster, the Common fruit fly, does not belong to the same family as Bactrocera dorsalis, the Oriental fruit fly; Drosophila melanogaster belongs to the family Drosophilidae whilst Bactrocera dorsalis belongs to the family Tephritidae (See Figure 3).

Common fruit flyOriental fruit flySize comparison

Scientific name: 

Drosophila melanogasterFamily: Drosophilidae

Significance:

Important model organism in genetics and developmental biology research

Adult's appearance:

Red eyes; Yellow or brown (tan) colour; Black stripes on dorsal surface of abdomen

Larvae's appearance:

Minute white maggots lacking legs and a defined head

Scientific name: 

Bactrocera dorsalisFamily: Tephritidae

Significance:

Notorious pest species known for causing immense economic losses

Adult's appearance:

Variable colour & pattern; prominant yellow and dark brown to black markings on dorsal surface of thorax; Generally with two horizontal black stripes and a longitudinal mark on dorsal surface of abdomen

Larvae's appearance:

10 mm long; creamy white colour

Drosophila melanogaster size:

1-3 mm body length

Bactrocera dorsalis size:

6-8 mm body length

Credits:

Drosophila melanogaster

Information: Animal Diversity Web

Drosophila melanogaster,” by Conrad Miller. Animal Diversity Web. URL: http://animaldiversity.org/accounts/Drosophila_melanogaster/ (accessed on 14 Nov 2016).


Image: Malcolm Storey © Copyright

Bactrocera dorsalis

Information: Plant Health Australia

“Oriental fruit fly complex – Fact sheet,” by Plant Health Australia. URL: http://www.planthealthaustralia.com.au/wp-content/uploads/2013/09/Oriental-fruit-fly-complex-FS-Papaya.pdf (accessed on 14 Nov 2016).


Image: Arina Adom

Figure 2: Comparison table showing differences between the Common fruit fly and Oriental fruit fly.

Figure 3: Phylogeny tree indicating positions of the Tephritidae and Drosophilidae families on the Schizophora phylogeny tree. Image adapted from Wiegmann et al.

 Wiegmann, B. N., M. D. Trautwein, I. S. Winkler et al., 2011. Episodic radiations in the fly tree of life. Proceedings of the National Academy of Sciences. Available from: https://www.researchgate.net/50395098_fig1_Fig-1-Combined-molecular-phylogenetic-tree-for-Diptera-Partitioned-ML-analysis-of (accessed on 22 Nov 2016).



2. Biology

2.1. Life History

In tropical environments, Oriental fruit flies breed throughout the year. Throughout her lifetime (typically 1-3 months), a female fly is able to typically lay between 1,200 to 1,500 eggs (under field conditions) and over 3,000 eggs (under optimum conditions)

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

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Figure 4: Gif showing adult Oriental fruit flies on an orchid. Video credits: YouTube

"Fruit flies, Oriental Mindoro, Philippines," by warrenlaurde. YouTube, 06 Jun 2011. Gif made using gifyoutube.com.




Eggs are laid in batches of 1-20 eggs per fruit, just under the fruit's skin, where fruit-decaying bacteria is subsequently deposited. Although ripe fruit are preferred for oviposition, oviposition on immature fruits has also been observed. Development from egg to adult is usually completed within about 16 days, however cooler weather conditions are known to delay development. Larvae (commonly known as maggots) develop within the fruit

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

“Oriental fruit fly,” byDepartment of Agriculture and Fisheries, Queensland Government, 19 Feb 2015. URL: https://www.daf.qld.gov.au/plants/health-pests-diseases/a-z-significant/oriental-fruit-fly (accessed on 14 Nov 2016).

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Figure 5: Image of oriental fruit fly larvae within a citrus fruit. Photo credit: Scott Bauer (permission pending)

“Oriental fruit fly larvae” U.S. Department of Agriculture (USDA) photo by Scott Bauer. Flickr.com, 05 March 2012. URL: https://flic.kr/p/bu2Xpw (accessed on 14 Nov 2016). (permission pending)

When mature, larvae emerge from the fruit and jump or drop onto the ground (watch the video below to see how the larvae jumps!).


Video 1: Video showing jumping tephritid larvae found inside a squash. Video credits: YouTube

“Jumping Tephritidae fruit fly maggots,” by hillbournesian. Youtube, 05 Oct 2011.





In the soil, they form tan to dark brown puparium. Once mature, the flies emerge from their puparia as adult flies. Young males often disperse over several kilometres before reaching sexual maturity and finding its mate! For this reason, Oriental fruit flies are known to spread far and fast, causing much damage to crop fruits 

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

“Oriental fruit fly,” byDepartment of Agriculture and Fisheries, Queensland Government, 19 Feb 2015. URL: https://www.daf.qld.gov.au/plants/health-pests-diseases/a-z-significant/oriental-fruit-fly (accessed on 14 Nov 2016).

. The Oriental fruit fly life cycle is summarised in the following figure.


Figure 6: Life Cycle of Tephritid fruit fly. Image credits: Adapted from various sources; Permission pending

Daniel, C. & J.Grunder, 2012. Integrated Management of European Cherry Fruit Fly Rhagoletis cerasi(L.): Situation in Switzerland and Europe, “Pupae of R. cerasi © 2012”. Insects, 3(4): 956-988 URL: http://www.mdpi.com/2075-4450/3/4/956/htm(accessed on 22 Nov 2016).

Bactrocera zonata eggs” by Russell IPMURL: http://russellipm-agriculture.com/en/insect/bactrocera-zonata (accessed on 22 Nov 2016).

[13-16].


2.2. Feeding Habits

The Oriental fruit fly is highly polyphagous and is able to feed on and infest a large variety of produce from fruits, vegetables and other plants. The USDA has recorded its' occurence on 478 kinds of fruit and vegetables as of 2016

USDA, 22 July 2016. A Review of Recorded Host Plants of Oriental Fruit Fly, Bactrocera dorsalis(Hendel) (Diptera: Tephritidae). Version 2.1 A Product of the USDA Compendium of Fruit Fly Host Information (CoFFHI), a Farm Bill Project.

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  • Apple
  • Apricot
  • Avocado
  • Banana
  • Bell pepper
  • Cactus
  • Cashew
  • Cherry
  • Chili
  • Citrus
  • Coffee
  • Cucumber
  • Date palm
  • Fig
  • Grape
  • Grapefruit
  • Guava
  • Lemon
  • Lime
  • Loquat
  • Mandarin
  • Mango
  • Nectarine
  • Orange
  • Papaya
  • Passion fruit
  • Peach
  • Pear
  • Persimmon
  • Pineapple
  • Plum
  • Pomegranate
  • Roseapple
  • Tangerine
  • Tomato
  • Walnut

Figure 7: Table showing some of the common host plants of B. dorsalis.



3. Economic Importance

The Oriental fruit fly has been known to cause up to billions of dollars in financial losses due to (1) the direct damage caused to fruit crops, (2) exportation and quarantine restrictions from areas with a history of fruit fly infestations and (3) management costs to eradicate existing infestations

“Oriental fruit fly larvae” U.S. Department of Agriculture (USDA) photo by Scott Bauer. Flickr.com, 05 March 2012. URL: https://flic.kr/p/bu2Xpw (accessed on 14 Nov 2016). (permission pending)

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Figure 8: Gif showing a damaged fruit infected with a B. dorsalis larva

“Alerta Verde: La Mosca Oriental de la Fruta,” by DaniSilva TV. Youtube, 21 Sep 2015. Gif made using gifyoutube.com.

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3.1. Damage to Crops

Regarded as the "most damaging pest of tropical horticulture in the world ", Oriental fruit flies are feared for their indiscriminate infestations on a wide range of produce, whether ripe or unripe. Damage caused by the fruit fly result from 1) oviposition in fruit and soft tissues of vegetative parts of certain plants, 2) feeding by the larvae, and 3) decomposition of plant tissue by invading secondary microorganisms

“Bactrocera dorsalis (Hendel),“ by Ronald F.L. Mau, Jayma L. Matin & J. M. Diez. Crop Knowledge Master, Apr 2007, URL: http://www.extento.hawaii.edu/Kbase/Crop/Type/bactro_d.htm (accessed on 15 Nov 2016).

. Often, much damage can occur before any obvious signs of infestation within a fruit are even observed

“Oriental fruit fly,” byDepartment of Agriculture and Fisheries, Queensland Government, 19 Feb 2015. URL: https://www.daf.qld.gov.au/plants/health-pests-diseases/a-z-significant/oriental-fruit-fly (accessed on 14 Nov 2016).

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Figure 9: (a) Photograph of an adult B. dorsalis fruit fly; (b) infection of the fruit guava by B. dorsalis; (c, d) eggs of B. dorsalis laid below the skin of the host fruit and the attacked fruit shows the signs of the ovipositional damage in the form of minute depressions; (e) the affected fruits soften at the site of infestation which then rot and drop down prematurely and (f) the maggots feed on the pulp of the fruits. Image credit: Bhagat et al.

Bhagat, D., Samanta, S. K. & Bhattacharya, S., 2013. Efficient Management of Fruit Pests by Pheromone Nanogels. Scientific Reports 3, 1294. doi:10.1038/srep01294


The first signs of an infestation are small discoloured patches on the skin fruit skin, which develop from the "sting" of the female fly during ovipositon. Once hatched, fruit fly larvae able to tunnel deeply into the fruit flesh for feeding, spreading widely within infested fruit and making the whole fruit unpalatable. In certain fruit types, maggot infestation results in tissue breakdown and internal rotting associated with maggot infestation, but this varies with the type of fruit attacked. Affected young fruit tend to become distorted, callused and usually drop prematurely whereas affected mature fruits develop a water soaked appearance. The larval tunnels subsequently provide entry points for bacteria and fungi that cause the fruit to rot further. When only a few larvae develop, damage consists of an unsightly appearance and reduced marketability because of the egg laying punctures or tissue break down due to the decay

Steiner, L. F., 1957. Field Evaluation of Oriental Fruit Fly Insecticides in Hawaii. Journal of Economic Entomology, 50: 16-24.

. Damage to crops has been estimated at between 50-80% in West Pakistan and even up to 100% in Malaysia

Mahmood, K., 2004. Identification of Pest Species in Oriental Fruit Fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) Species Complex. Pakistan Journal of Zoology, 36(3): 219-230.

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Watch the video below to see the impacts of Oriental fruit fly infestations on the community in Mpumalanga, South Africa.

Video 2: News report of the impacts of Oriental fruit fly infestations in Mpumalanga, South Africa. Video credits

“Mpumalanga citrus farmers hit hard by Oriental Fruit Flies,” by SABC Digital News. SABC YouTube Channel, 08 Apr 2016.


3.2. Quarantine

Due to the potential damage caused by these flies, coupled with their ability to be active dispersers and breed agressively as adults, the Oriental fruit fly is regarded as an invasive species in many countries around the world. These countries guard heavily against the introduction of the Oriental fruit fly through immigration in hopes of avoiding massive economic loss to agricultural farmers. Fresh agricultural produce being transported into each country is meticulously monitored and quarantined in order to isolate and eliminate the accidental introduction of these flies. As a result, much economic loss is caused by trade restrictions. Malaysian fruits, for example, cannot be freely exported to lucrative markets like USA, Japan and Australia, because of strict quarantine regulations in these countries, which prohibit entry of fresh fruits from the fruit flies infested countries unless proper disinfestation treatments are carried out

Singh, R.B., 1991. Significance of fruit flies in fruit and vegetable production in the Asia-Pacific region. Proceedings First International Symposium on Fruit flies in the Tropics (eds. S. Vijaysegaran and A.G. Ibrahim), pp. 11- 29. Kuala Lumpur, 1988. Malaysian Agricultural Research and Development Institute, Kuala Lumpur.

. This situation is also faced in the Philippines, Thailand, Indonesia, India, Taiwan and China.


Figure 10: Extract from a newspaper article highlighting quarantine measures taken after an Oriental fruit fly outbreak. Image credit: Florida Department of Agriculture and Customer Services

“Florida growers, Adam Putnam debate aerial pest spray for invasive Oriental fruit fly,” by Alex Harris. Miami Herald, 21 Sep 2015. Hoested on MiamiHerald.comhttp://www.miamiherald.com/news/local/environment/article35949096.html(accessed on 21 Nov 2016).

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3.3. Management

Fortunately, populations of the Oriental fruit fly are manageable and can be eradicated, albeit a huge financial cost incurred. In 1985, all Japanese territories were declared free of the Oriental fruit fly after an 18-year program of eradication combining insecticide-impregnated fiberblocks or cotton containing the powerful male attractant methyl-eugenol, and the sterile insect (sterile male) technique. Steiner traps baited with a lure and toxicant are also used to monitor the presence and control of the flies. In 1995, Oriental fruit fly established near Cairns and cost $33.5 million and took 4 years to eradicate

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

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4. Distribution

4.1. Worldwide distribution

Native to the tropical Asian region, the fruit flies have spread throughout the world and become a prominent pest species across multiple continents. The fly is believed to be introduced through the import of infected fruits from native regions in Asia.

Figure 11: Worldwide distribution of Bactrocera dorsalis. Key: Black- Present, no further details; Blue- Widespread; Red- Localised; Image credit: Copyright © 2016 Centre for Agriculture and Biosciences International (CABI)

Bactrocera dorsalis (Oriental fruit fly) Datasheet,” by Centre for Agriculture and Biosciences International. CABI.org, 23 Sep 2016. URL: http://www.cabi.org/isc/datasheet/17685 (accessed 14 Nov 2016).

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4.2. Asian distribution

Bactrocera dorsalis is native to tropical Asian countries such as Singapore, India, Malaysia and Bangladesh. In countries such as Cambodia and China, B. dorsalis is regarded as an invasive species

EPPO (2015) PQR - EPPO database on quarantine pests (available online). http://www.eppo.int

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Figure 12: Asian distribution of Bactrocera dorsalis. Key: Black- Present, no further details; Blue- Widespread; Yellow- Occasional or few reports; Image credit: Image credit: Copyright © 2016 Centre for Agriculture and Biosciences International (CABI)

Bactrocera dorsalis (Oriental fruit fly) Datasheet,” by Centre for Agriculture and Biosciences International. CABI.org, 23 Sep 2016. URL: http://www.cabi.org/isc/datasheet/17685 (accessed 14 Nov 2016).


4.3. African distribution

First introduced to Africa through Kenya in 2003. Since then, most countries within sub-Saharan Africa have faced B. dorsalis infestations

Goergen, G., J. F. Vayssières, D. Gnanvossou & M. Tindo, 2011. Bactrocera invadens (Diptera: Tephritidae), a new invasive fruit fly pest for the Afrotropical Region: host plant range and distribution in West and Central Africa. Environmental Entomology. 40: 844-854

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Figure 13: African distribution of Bactrocera dorsalis.Key: Black- Present, no further details; Blue- Widespread; Red- Localised; Image credit: Image credit: Copyright © 2016 Centre for Agriculture and Biosciences International (CABI) 

Bactrocera dorsalis (Oriental fruit fly) Datasheet,” by Centre for Agriculture and Biosciences International. CABI.org, 23 Sep 2016. URL: http://www.cabi.org/isc/datasheet/17685 (accessed 14 Nov 2016).



4.4. Pacific Islands distribution

Bactrocera dorsalis was accidentally introduced in the United States between 1944 to 1945 and is now present and a major threat on all major Hawaiian islands

“Bactrocera dorsalis (Hendel),“ by Ronald F.L. Mau, Jayma L. Matin & J. M. Diez. Crop Knowledge Master, Apr 2007, URL: http://www.extento.hawaii.edu/Kbase/Crop/Type/bactro_d.htm (accessed on 15 Nov 2016).

Figure 14: Pacific Islands distribution of Bactrocera dorsalis.Key: Black- Present, no further details; Blue- Widespread; Image credit: Copyright © 2016 Centre for Agriculture and Biosciences International (CABI)

Bactrocera dorsalis (Oriental fruit fly) Datasheet,” by Centre for Agriculture and Biosciences International. CABI.org, 23 Sep 2016. URL: http://www.cabi.org/isc/datasheet/17685 (accessed 14 Nov 2016).


Not shown on map: Bactrocera dorsalis has also been reported in Queensland, Australia

EPPO (2015) PQR - EPPO database on quarantine pests (available online). http://www.eppo.int

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5. Description

5.1. Adult

The adult, which is noticeably larger than a house fly, has a body length of about 7.0-8.0 mm; the wing is about 7.3 mm in length. The color of the fly is very variable, but there are prominant yellow and dark brown to black markings on the thorax (a). Generally, the abdomen has two horizontal black stripes (b) and a longitudinal median stripe extending from the base of the third segment to the apex of the abdomen (c). These markings may form a T-shaped pattern, but the pattern varies considerably. The wings are clear (d). In females, the ovipositor is very slender and sharply pointed (e)

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

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Figure 15: Adults of the Oriental fruit fly. Image adapted from Okinawa Prefectural Fruit Fly Eradication Project Office

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).


5.2. Larva

The third-instar, which has a typical maggot appearance, is about 7.5-10.0 mm long and 1.5-2.0 mm wide and creamy white coloured

White, I.M., Elson-Harris, M.M., 1994. Fruit Flies of Economic Significance. Their Identification and Bionomics. Wallingford, UK: CAB International.

. The only band of spinules encircling the body is found on the first segment. The external part of the anterior respiratory organs, the spiracles, located one on each side of the pointed or head end of the larva, has an exaggerated and deflexed lobe at each side and bears many small tubercles. The caudal segment is very smooth. The posterior spiracles are located in the dorsal third of the segment as viewed from the rear of the larva

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

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The mature larva emerges from the fruit, drops to the ground, and forms a tan to dark brown puparium about 4.9 mm in length.

Figure 16: Larvae of the Oriental fruit fly. Image adapted from Okinawa Prefectural Fruit Fly Eradication Project Office

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

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5.3. Puparium

Barrel-shaped with most larval features unrecognisable. White to yellow-brown. Usually approximately 60-80% the length of the larva

White, I.M., Elson-Harris, M.M., 1994. Fruit Flies of Economic Significance. Their Identification and Bionomics. Wallingford, UK: CAB International.

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5.4. Egg

The white, elongate and elliptical egg measures about 1.17 x 0.21 mm and has a chorion without sculpturing.

Figure 17: Eggs of the Oriental fruit fly. Image adapted from Okinawa Prefectural Fruit Fly Eradication Project Office

“oriental fruit fly,” by H.V. Weems, J.B. Heppner, James L. Nation & Gary Steck. University of Florida, Florida Department of Agriculture and Consumer Services, Aug 2016. URL: http://entnemdept.ufl.edu/creatures/fruit/tropical/oriental_fruit_fly.htm (accessed on 14 Nov 2016).

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5.5. Official Diagnosis

First flagellomere shorter than ptilinal fissure, face with a black spot in each antennal furrow. Tomentum pattern without longitudinal gap in the middle of prescutum. Scutum colour (other than vittae) red-brown to black. Lateral vittae of scutum present, parallel-sided, yellow, ending at or just behind intra-alar seta. Medial vitta of scutum absent. Scutellum largely yellow. Setae: anterior supra-alar present, prescutellar present, scutellar one pair. Anepisternal stripe not extended forward. Wing costal band width from vein subcostal to slightly below vein R4+5 at wing apex; confluent with vein R2+3 in depth. Cell basal costal without microtrichia. Cell costal with microtrichia in the anterodistal corner only. Cell basal radial with microtrichae at the base. Wing length: 5.4–6.9mm. Foretibia pale fuscous to dark fuscous, mid-tibia pale fuscous to fuscous, hind tibia fuscous to dark fuscous. Femora largely fulvous. Abdominal terga free, except I and II. Terga markings: terga III–V withmedial longitudinal black band, tergum III with a basal narrow transverse black band, terga IV and V with black triangular lateral markings, sometimes longitudinal black bands on lateral margins and sometimes without any mark. Tergum III (males) with pecten. Sternum V (males) with V-shaped notch. Posterior surstylus lobe short. Males attracted to methyl eugenol

Schutze, M. K., N. Aketarawong, W. Amornsak et al., 2014. Synonymization of key pest species within the Bactrocera dorsalis species complex (Diptera: Tephritidae): Taxonomic changes based on a review of 20 years of integrative morphological, molecular, cytogenetic, behavioural and chemoecological data. Systematic Entomology, DOI: 10.1111/syen.12113.

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6. Taxonomy & Systematics

6.1. Original Description

Bactrocera dorsalis was first described by Friedrich Hendel as Dacus dorsalis in the "Entomologischen Mitteilungen" or "Entomological Messages" in 1912.

Figure 18: Frist Description of the oriental fruit fly in the "Entomologischen Mitteilungen" or "Entomological Messages" in 1912. Image credit: Biodiversity Heritage Library

“Original description of Dacus dorsalis inEntomologischen Mitteilungen,” byFriedrich Hendel, 1912. Image obtained from Biodiversity Heritage Library (BHL). URL: http://biodiversitylibrary.org/page/10424191 (accessed 14 Nov 2016).


6.2. Type Information

The holotype of Dacus ferrugineus Fabricius is currently located in the Natural History Museum of Denmark. although the specimen is nearly entirely destroyed, the taxonomically informative ‘red-brown’ colour of the thorax is still evident (See Fig.19)

“Holotype of Dacus ferrugineus Fabricius located in the Natural History Museum of Denmark,” by Verner Michelsen, Oct 2014. One and the same: Integrative taxonomic evidence that Bactrocera invadens (Diptera: Tephritidae) is the same species as the Oriental fruit fly Bactrocera dorsalis - Scientific Figure on ResearchGate. URL: https://www.researchgate.net/267761592_fig3_Figure-7-Holotype-of-Dacus-ferrugineus-Fabricius-located-in-the-Natural-History-Museum (accessed on 23 Nov 2016).

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Figure 19: Holotype of Dacus ferrugineus Fabricius located in the Natural History Museum of Denmark. Photo credit: Verner Michelsen

“Holotype of Dacus ferrugineus Fabricius located in the Natural History Museum of Denmark,” by Verner Michelsen, Oct 2014. One and the same: Integrative taxonomic evidence that Bactrocera invadens (Diptera: Tephritidae) is the same species as the Oriental fruit fly Bactrocera dorsalis - Scientific Figure on ResearchGate. URL: https://www.researchgate.net/267761592_fig3_Figure-7-Holotype-of-Dacus-ferrugineus-Fabricius-located-in-the-Natural-History-Museum (accessed on 23 Nov 2016).

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6.3. Common Names

English: Oriental fruit fly
Malay: lalat buah
Spanish: mosca oriental de la fruta
French: mouche de fruits asiatique; mouche orientale des arbres fruitiers
Portuguese: la mosca oriental das frutas
Germany: Orientalische Fruchtfliege
Japan: mikan-ko-mibae
Netherlands: mangga-vlieg

6.4. Scientific Name & Synonyms

Scientific Name: Bactrocera dorsalis (Hendel, 1912)

Originally described by Hendel in 1912 as Dacus dorsalis, the Oriental fruit fly has since been redescribed, reclassified and renamed multiple times by numerous authors internationally. One major cause was the large variability in colouration and patterning, between the otherwise morphologically and genetically similar pest species within the Bactrocera dorsalis species complex.This resulted in the hindrance of the development of reliable diagnostic characters to distinguish between intra- and inter-specific variation. The prolonged difficulties in differentiating putative species, coupled with the highly disjunct geographic distribution of closely-related species within the Bactrocera dorsalis species complex, has resulted in grouping errors in the form of separate populations of B. dorsalis worldwide being described as new separate Bactroceran species

Schutze, M. K., N. Aketarawong, W. Amornsak et al., 2014. Synonymization of key pest species within the Bactrocera dorsalis species complex (Diptera: Tephritidae): Taxonomic changes based on a review of 20 years of integrative morphological, molecular, cytogenetic, behavioural and chemoecological data. Systematic Entomology, DOI: 10.1111/syen.12113.

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6.4.1. Case study: Bactrocera invadens

One example of a grouping error was a group of B. dorsalis specimens detected in Kenya in 2003. After comparison with B. dorsalis specimens from the purported native range of Sri Lanka, the Kenyan material was described as a new species, Bactrocera invadens 

Lux, S.A., R.S. Copeland, I.M. White et al., 2003. A new invasive fruit fly species from the Bactrocera dorsalis (Hendel) group detected in East Africa. Insect Science and its Application, 23, 355–361.

. This was in spite of the considerably similar morphology of Kenyan specimens to the B. dorsalis specimens obtained from Sri Lanka

Drew, R.A.I., K. Tsuruta & I.M. White, 2005 A new species of pest fruit fly (Diptera: Tephritidae: Dacinae) from Sri Lanka and Africa. African Entomology, 13, 149–154.

. What led to this decision was in particular, the scutum colour of the Kenyan specimens which ranged "from pale red-brown to black with the existence of variable lanceolate-patterned intermediates". This was in contrast with the B. dorsalis description in which the scutum had been defined as "strictly black"

Drew R. A. I. & D. L. Hancock, 1994. The Bactrocera dorsalis complex of fruit flies in Asia. Bulletin of Entomological Research (Suppl. 2), CAB International, Wallingford, UK.

. As a result of the confusion over the unreliable discrimination between B. dorsalis and B. invadens, significant problems with African horticulture and food security emerged, especially with regards to quarantine and pest management policies

Khamis, F.M., D.K. Masiga, S.A. Mohamed et al., 2012. Taxonomic identity of the invasive fruit fly pest, Bactrocera invadens: concordance in morphometry and DNA barcoding. PLoS One, 7, e44862.

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6.4.2. Final resolution

Fortunately, in 2009, a major international collaboration was established by the United Nations Food and Agriculture Organization (UN-FAO) and the International Atomic Energy Agency (IAEA) with the aim of resolving biological species limits among several highly morphologically and genetically similar species: Bactrocera papayae Drew & Hancock, Bactrocera philippinensis Drew & Hancock, Bactrocera carambolae Drew & Hancock, Bactrocera invadens Drew, Tsuruta & White and Bactrocera dorsalis (Hendel, 1912). The study, published in 2014, resolved the problem by using multidisciplinary evidence (morphological, molecular, cytogenetic, behavioural and chemoecological data) to synonymise B. dorsalis, B. invadens and B. papayae. Bactrocera dorsalis (Hendel) was subsequently declared a senior synonym and a more comprehensive re-description was published to include intra-specific colour variations. The following are the synonyms of Bactrocera dorsalis (Hendel, 1912) listed in the paper

Schutze, M. K., N. Aketarawong, W. Amornsak et al., 2014. Synonymization of key pest species within the Bactrocera dorsalis species complex (Diptera: Tephritidae): Taxonomic changes based on a review of 20 years of integrative morphological, molecular, cytogenetic, behavioural and chemoecological data. Systematic Entomology, DOI: 10.1111/syen.12113.

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6.4.3. Other synonyms

SynonymsAuthor, YearRemarks
Musca ferrugineaFabricius, 1794Preoccupied by Musca ferruginea Scopoli, 17634
Dacus ferrugineusFabricius, 1805
Dacus dorsalisHendel, 1912Lectotype ♀ in The Natural History Museum, London, U.K.
Bactrocera ferrugineaBezzi, 1913
Chaetodacus ferrugineusvar. dorsalisHendel, 1915
Chaetodacus ferrugineusBezzi, 1916
Chaetodacus ferrugineus dorsalisBezzi, 1916
Chaetodacus ferrugineusvar. okinawanusShiraki, 1933; Hardy & Adachi, 1956; Hardy, 1969
Dacus (Strumeta) dorsalisHardy & Adachi, 1956; Hardy, 1969; 1973; 1974
Strumeta dorsalisHering, 1956
Strumeta ferrugineaHering, 1956
Strumeta dorsalis okinawaShiraki, 1968
Dacus (Bactrocera) dorsalisHardy, 1977; Drew, 1982; 1989
Dacus (Bactrocera) semifemoralisTseng et al., 1992synonymized by Drew & Romig, 2013
Bactrocera (Bactrocera) dorsalisDrew & Hancock, 1994; Norrbom et al., 1998; Mahmood & Hasan, 2005; White, 2006; Drew et al., 2007Lectotype designation by Drew & Hancock, 1994
Bactrocera (Bactrocera) variabilisLin & Wang, 2011 in Lin et al., 2011Holotype in HEIQ; synonymized by Drew & Romig, 2013: 76
Bactrocera (Bactrocera) philippinensisDrew & Hancock, 1994synonymized with B. papayae by Drew & Romig, 2013
Bactrocera (Bactrocera) papayaeDrew & Hancock, 1994syn.n.
Bactrocera (Bactrocera) invadensDrew et al., 2005syn.n.

Figure 20: Table of Bactrocera dorsalis synonyms

Schutze, M. K., N. Aketarawong, W. Amornsak et al., 2014. Synonymization of key pest species within the Bactrocera dorsalis species complex (Diptera: Tephritidae): Taxonomic changes based on a review of 20 years of integrative morphological, molecular, cytogenetic, behavioural and chemoecological data. Systematic Entomology, DOI: 10.1111/syen.12113.

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6.5. Taxonomic Hierarchy

The classification below reflects above species-level rankings (from Kingdom to Species) for B. dorsalis:

Figure 21: Taxonomic hierarchy of B. dorsalis (Hendel, 1912). Data obtained from UniProt & ITIS

Retrieved [14 Nov 2016], from the UniProt Consortium, UniProt: a hub for protein information, Nucleic Acids Res, http://www.uniprot.org/taxonomy/27457

 Retrieved [14 Nov 2016], from the Integrated Taxonomic Information System on-line database, http://www.itis.gov



7. Phylogeny

The position of the Tephritidae family within Diptera: Schizophora can be observed in Fig. 3, a subsection of the combined molecular phylogenetic tree for Diptera. The combined phylogenetic tree was produced through partitioned Maximum Likelihood (ML) analysis of data calculated in RAxML. Molecular and morphological data from 149 of 157 dipteran families, including 30 kb from 14 nuclear loci and complete mitochondrial genomes as well as 371 morphological characters were used in this analysis

 Wiegmann, B. N., M. D. Trautwein, I. S. Winkler et al., 2011. Episodic radiations in the fly tree of life. Proceedings of the National Academy of Sciences. Available from: https://www.researchgate.net/50395098_fig1_Fig-1-Combined-molecular-phylogenetic-tree-for-Diptera-Partitioned-ML-analysis-of (accessed on 22 Nov 2016).

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Fig 21: Phylogenetic tree of Tephritidae family based on mitochondrial genomes. Squares at the nodes are Bayesian posterior probabilities for 1, 2, 5 and 6, ML bootstrap values for 3, 4, 7 and 8. Dataset of PCG123, 1 and 3, PCG123RNA, 2 and 4, PCG12, 5 and 7, PCG12RNA, 6 and 8. Black indicates posterior probabilities = 1.00 or ML bootstrap = 100, gray indicates posterior probabilities ≥ 0.90 or ML bootstrap ≥ 70, white indicates posterior probabilities <0.90 or ML bootstrap < 70, ‘ns’ indicates not support, *indicates posterior probabilities = 1.00 or ML bootstrap = 100 in eight trees

Jiang F., X. Pan, X. Li et al., 2016. The first complete mitochondrial genome of Dacus longicornis(Diptera: Tephritidae) using next-generation sequencing and mitochondrial genome phylogeny of Dacini tribe. Scientific Reports, 6.

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Within the family Tephritidae, the following phylogenetic tree has been obtained (Fig. 21) using Bayesian and ML analysis of mitochondrial DNA sequences obtained through next-generation sequencing (NGS)

Jiang F., X. Pan, X. Li et al., 2016. The first complete mitochondrial genome of Dacus longicornis(Diptera: Tephritidae) using next-generation sequencing and mitochondrial genome phylogeny of Dacini tribe. Scientific Reports, 6.

. The tree is fairly stable with 8 out of 16 nodes within the Tephritidae tree being well supported (Bayesian posterior probabilities = 1.00 or ML bootstrap = 100 and 4 out of the remaining nodes having majority relatively high support (posterior probabilities ≥ 0.90 or ML bootstrap ≥ 70). Results show that both the family Tephritidae and the tribe Dacini (represented in the figure by genera Dacus and Bactrocera) are monophyletic. The genus Bactrocera, on the other hand is not monophyletic.


Within the 
Bactrocera dorsalis species complex, a separate phylogenetic study was conducted in 2013 (before B. dorsalis was synonymised with B. invadens, B. papayae and B. philippinensis 

Schutze, M. K., N. Aketarawong, W. Amornsak et al., 2014. Synonymization of key pest species within the Bactrocera dorsalis species complex (Diptera: Tephritidae): Taxonomic changes based on a review of 20 years of integrative morphological, molecular, cytogenetic, behavioural and chemoecological data. Systematic Entomology, DOI: 10.1111/syen.12113.

) to study the phylogeny of several Bactrocera species. A molecular phylogenetic tree was build with molecular data obtained from six loci (cox1, nad4-3′, CAD, period, ITS1, ITS2) for approximately 20 individuals from each of 16 sample sites. Specimens used were morphoogically sorted into the "ingroups" B. dorsalis, B. papayae, B. philippinensis and B. carambolae. Several "outgroup species" were also used in this study, some being species within the B. dorsalis species complex (namely the Australian species B. cacuminata and B. opiliae, and the Philippine species B. occipitalis (which occurs sympatrically with B. philippinensis) and some not being within the species complex (namely B. musae and B. tryoni). The resultant tree obtained using Bayesian and ML analysis showed the non-monophyly of B. dorsalis, B. papayae and B. philippinensis and supports the more recent synonymisation of the three species as a single species under B. dorsalis (Box 6 in Fig. 22). The tree also strongly supported the monophyly of B. carambolae and its' distinction from the remaining 3 ingroup species (Box 5 in Fig 22).

Figure 22: Phylogenetic reconstruction based on sequence data for specimens for which all six loci were sequenced for Bactrocera spp. in the current study (236 specimens, 3435 bp alignment). Bayesian posterior probabilities are listed above each branch, maximum likelihood bootstrap values below. For clarity only supports for backbone nodes are shown; in cases where actual nodal support is absent, posterior probability support values are >0.5 except for those marked with an asterisk (>0.95). All nodes <0.5 are collapsed. Results of clade monophyly statistics are shown as boxes (1–5 = a priori group analysis; a–g = root‐to tip analysis), with only those achieving 4/5 (orange) or 5/5 (red) shown. A priori taxonomic identifications of individual specimens within the dorsalis complex ‘ingroup’ have been colour coded [i.e. B. dorsalis s.s. (purple), B. papayae (dark blue), B. philippinensis (light blue) and B. carambolae (green)]. Image credit:

Boykin, L. M., M. K. Schutze, M. N. Krosch et al., 2014. Multi-gene phylogenetic analysis of south-east Asian pest members of the Bactrocera dorsalis species complex (Diptera: Tephritidae) does not support current taxonomy. Journal of Applied Entomology, 138: 235–253. doi:10.1111/jen.12047



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8. References



This page was authored by Nur Arina Mohd Adom
Last curated on 2016