- Monitoring fruit flies: (i) commercial growers – traps for male flies with wicks containing pheromone and insecticide (spinosad, spinetoram, fipronil). Place traps on lower branches of crop or in trees nearby for low-growing vegetable; (ii) smallholders – pheromone not always accessible, therefore assume fruit flies always present.
- Commercial sprays: See examples given in Full Fact Sheet and follow manufacturers’ instructions. Note the following:
- Contains protein (often yeast waste from brewer), plus insecticide (sometimes with sugar and thickening agent, e.g., guar gum or xanthium gum).
- Insecticides: spinosad; spinetoram; fipronil; malathion or abamectin.
- Start spraying after fruit set, continuing until 3 days before harvest (malathion), 7 days (abamectin); spinosad has zero withholding period – use as directed.
- Spray 'spots' as a stream, with nozzle fully open, NOT as a fine spray)
- Smallholder home-made traps:
- Use plastic soft drink or water bottles (600mL is best; 1.25L can be used, but require more bait)
- Make 3-4 holes, size of small finger on shoulder or above halfway up the bottle
- Fill to about ¼ full with mixture made of:
- 1L water.
- 50mL cloudy ammonia.
- 1tbsp sugar.
- 5mL vanilla essence (artificial).
- 1tbsp yeast extract (e.g., Vegemite®, or Marmite®).
- A few drops non-scented dish-washing liquid.
- Clean containers and replace weekly.
- Hang 2-3 in shady parts of large tree, 1.5-2m above ground, 3-4m apart.
- Alternatively, make up (i) 1tsp of Vegemite® or Marmite®; 1tsp sugar; 2-3 drops non-scented dish-washing liquid; OR (ii) blend host fruit in 1L water (liquid enough to drown adult flies) and place in plastic bottles with holes (see above).
Pacific Pests, Pathogens and Weeds - Online edition
Pacific Pests, Pathogens, Weeds & Pesticides
Fruit fly bait sprays & traps (507)
AUTHORS Graham Walker & Grahame Jackson
Information from Making a fruit fly trap. Department of Primary Industries and Regional Development. Western Australia. (https://www.agric.wa.gov.au/sites/gateway/files/Make%20a%20fruit%20fly%20trap.pdf); and Messing R (1999) Managing fruit flies in farms in Hawaii. Cooperative Extension Service, College of Tropical Agriculture & Human Resources, University of Hawaii at Mania. Hawaii. (https://www.ctahr.hawaii.edu/oc/freepubs/pdf/IP-4.pdf).
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.
Measurements: tsp = teaspoon; tbsp = tablespoon; mL = millilitre; L = litre; m = metre; g = gram.