Fruit Fly Control
Mediterranean fruit fly (Ceratitis capitata) is a serious horticultural pest in Western Australia. It attacks a range of cultivated fruits and some fruiting vegetables.
Medfly, as it is commonly known, has been recorded to infest more than 200 hosts worldwide. The first sign of damage is often larvae-infested or ‘stung’ fruit. Stinging is caused by the female laying eggs into unripened or ripe fruit.
Larvae may develop from the eggs, depending on when they are laid and the fruit type.For example, stings can occur in apples and peaches when they are unripe, but the eggs do not hatch at this stage. As the fruit ripens the eggs can develop.
Chemical control
Two chemical control techniques, baiting, and lure and kill, are recommended. Best control is achieved if both treatments are undertaken.
Capes Fruit Tree Care can manage a Fruit Fly control program for your property, or can supply the Chemicals and Equipment to manage Fruit Fly yourself. Get in touch to find out more.
Baiting
You should start during the early stage of fruit development when the fruit is a third of its final size and continue until all fruit has been harvested.
Females require a source of protein to mature their eggs and to maintain egg production. They usually obtain protein from fruit juice, bacteria and bird droppings. Baiting consists of applying coarse droplets of a protein liquid, laced with insecticide, to leaves. Male and female medflies are attracted to the protein as they forage for food, feed on it, and acquire a lethal dose of insecticide. Baiting targets only medfly adults and conserves beneficial insects.
Baiting may not provide control of Medfly in crops that are highly susceptible, or in high pressure areas such as in suburbs with many established fruit trees.
Female Medflies may find ripening stone fruit more attractive than baits. Effectiveness is increased if applied over a wide area such as in a community baiting scheme – so encourage your neighbours to also bait their trees.The bait is applied to the foliage as a coarse spot spray of 60–100mm for each tree depending on size. Entire tree coverage is not necessary as the flies are attracted to the protein by smell. The bait can be applied with a garden pressure sprayer, hand-held spray bottle, or flung onto foliage from a bucket with a paint brush. Make sure that the droplets are large — at least 2mm across.
As the insecticides used in baits have a short residual life, baits needs to be re-applied at weekly intervals. They also need to be re-applied if there is more than 5mm of rain.
Capes Fruit Tree Care uses the organic product Naturalure for Fruit Fly baiting, which we also supply. Get in touch to order.
Naturalure Technical Manual PDF
Lure and kill traps
Lure and kill devices work in a similar way to baits, exploiting the need for female Medflies to obtain dietary protein for egg production. Traps are hung on trees and the protein in the trap attracts male and female flies. Depending on the design, the flies drown or obtain a lethal dose of insecticide.
Nurseries sell a lure and kill device which consists of a plastic container containing a liquid that is attractive to Medflies. The flies enter through small holes in the lid, and eventually drown in the liquid. Freshly-killed flies float on the surface.
Devices should be hung 1.5-2m above the ground in fruit trees. These do not need to be fruiting at the time. Try to place the device in the shady part of the tree. Some traps can also be placed in nearby non-fruiting trees where flies may shelter.
The attractiveness of food lures extends just a few metres, so traps should ideally be no more than 5–6m apart.
Traps may dry out during summer and should be topped up with more liquid. If a trap dries out, medflies may still be attracted, but will not be killed. When disposing of the trap contents, make sure that you do so away from fruit trees as the liquid may attract medflies.
Lure and kill devices are not likely to kill all flies present, as the ripening fruit may be more attractive to the female medfly than the trap contents, so they are best used in conjunction with baiting.
Capes Fruit Tree Care uses Ceratrap traps and lures, which we also supply. Get in touch to order.
Ceratrap Technical Information PDF