- Widespread. Australia (Queensland), Guam, Kiribati, Nauru, MNI, PNG, Solomon Islands.
- Major invasive pest of cucumber family, also Solanum crops.
- Eggs (plus fruit fly-beneficial bacteria) laid in flowers and fruits giving a characteristic ‘sting’. Bacteria rot flesh providing food for maggots, and fruits usually fall to groundwhere larvae pupate. Adults, size of slender large house fly, bright yellow markings on thorax, T-shaped mark on abdomen, and smoky-brown marks at wing tips and back of wings along veins. Life cycle 3-5 weeks. Adults survive many weeks.
- Spread on the wing (moderately strong flier), and as larvae in infested fruit.
- Natural enemies: Psyttalia fletcheri (from India to Hawaii) - moderate mortality in Momordica, limited in cultivated fruit.
- Biosecurity: technologies and schemes to facilitate trade, including:
- post-harvest measures: HTFA (high temperature forced air); low temperature; insecticide dips; irradiation.
- area freedom, or area-wide management.
- consider in-country quarantines where melon fly is not widespread, or where countries free from melon fly border those infested.
- Cultural control: (i) monitor – trap male flies with pheromone (cure-lure); regularly check ripe fruit; (ii) protein baits – use yeast autolysate and insecticide as a spot spray; (iii) hygiene – bag fruit; harvest early; pick up fallen fruit, and remove those damaged but still on the crop, and destroy; (iv) crop rotation; (v) destroy remains of harvest.
- Eradication: define quarantine area; control fruit movement; remove fruit from trees and collect fallen fruit, protein bait/insecticide sprays; male annihilation; possibly SIT (sterile insect technique).
- Chemical control: protein bait (yeast hydrolysate) plus insecticide.
Pacific Pests, Pathogens, Weeds & Pesticides
Melon fly (505)
Photo 1. Premature yellowing is the first external sign of damage (arrowed) on bitter gourd caused by melon fly, Zeugodacus cucurbitae. Yellowing of this kind results from egg-laying or larval feeding.
Zeugodacus cucurbitae; known previously as Bactrocera (Zeugodacus) cucurbitae, and Bactrocera cucurbitae.
AUTHORS Graham Walker & Grahame Jackson
Information from Allwood AJ, et al. (1999) Host plant records for fruit flies (Diptera: Tephritidae) in South-East Asia. The Raffles Bulletin of Zoology. Supplement 7. 92 pp. (Complete host list in Asia); and Allwood AJ, Drew RAI (1997) Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp.; and Melon fruit fly (Undated) Fact sheet. Plant Health Australia. (https://www.planthealthaustralia.com.au/wp-content/uploads/2013/09/Melon-fruit-fly-FS.pdf); and Anon (2020) Melon fly. Business Queensland. Queensland Government. (https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/crop-growing/priority-pest-disease/melon-fly); and The Australian Handbook for the Identification of Fruit Flies (2018) Plant Health Australia. Canberra, ACT. (Version. 3.1). (https://www.planthealthaustralia.com.au/wp-content/uploads/2018/10/The-Australian-Handbook-for-the-Identification-of-Fruit-Flies-v3.1.pdf); and Waterhouse DF (1993) Pest fruit flies in the oceanic Pacific. Biological Control Pacific Prospects - Supplement 2. ACIAR, Canberra; and Garcia FRM, et al. (2020). Biological control of tephritid fruit flies in the Americas and Hawaii: A review of the use of parasitoids and predators. Insects 11(10): 662. (https://pubmed.ncbi.nlm.nih.gov/32993000/); and from Yates. Fruit fly control in your garden (https://www.yates.com.au/plants/problem-solver/pests/fruit-fly/). Photo 1 Melon Fly (Zeugodacus cucurbitaceae). Scott Bauer, USDA Agricultural Research service, Bugwood.org. Photos 7-10 Walker K (2006) Melon Fruit Fly (Bactrocera cucurbitae). Museum of Victoria. PaDIL - http://www.padil.gov.au. Diagram McDougall S, et al. (2013). Tomato, capsicum, chilli and eggplant: A field guide for the identification of insect pests, beneficials, diseases and disorders in Australia and Cambodia. Australian Centre for International Agricultural Research (ACIAR). (http://aciar.gov.au/files/mn-157/index.html).
Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.