Queensland Fruit Fly Control in your Garden

1. Queensland Fruit Fly
Queensland Fruit Fly
(Bactrocera tryoni)
Queensland Fruit Fly was found in metropolitan Melbourne in January 2008. This is a matter of very
great concern. Queensland Fruit Fly is a very serious pest of great economic significance because of
the damage caused to the fruit industry. It may affect the home gardener who grows fruit and
vegetables as well as the horticulture industries.
Plant Health Australia (PHA) is currently facilitating a major national initiative to improve the
management and eradication of fruit fly. Those who live in an infected area should do all they can to
eliminate this pest. This means caring for your fruit trees and disposing of all fruit correctly.
Inspect Regularly
Home grown fruit should be inspected on a regular basis for the presence of fruit fly larvae. The
larvae may be easier to find than the adult fruit fly.
The adult fruit fly has a wasp like appearance. It is about 7 mm long. It is a reddish brown colour
with yellow oval markings. The female fly lays eggs in the ripening fruit and the larvae burrows
inside the fruit and so destroys it.
Most fruits can be affected including peaches, oranges, apples, pears, tomatoes and capsicums.
There are traps which can be used to detect the presence of fruit fly.

2. Some fruit, such as banana and avocado may be picked in a mature green condition, before fruit fly
can lay its eggs in the fruit.
Control
If you grow any fruit trees they should be pruned regularly to a height that the fruit can be picked.
Ripe fruit should be removed from the tree before it falls to the ground. Any fruit which does fall to
the ground should be collected immediately and sealed in a plastic bag. The sealed bag should be
left in the sun for 3-7 days so that the heat will kill the larvae and prevent them developing into fruit
fly adults.
There are chemicals which can be used to prevent infestations or control fruit fly but there are also
other methods, such as Organic Crop Protectant’s Naturalure™ .
This fruit fly control bait controls all species of fruit fly.
Naturalure contains specially formulated proteins and carbohydrates that are highly attractive to
both the female and male fruit fly. The bait contains a BFA registered organic insecticide called
Spinosad which is very toxic to fruit fly, but very safe to mammals and other animals. One of the
great advantages Naturalure has over other lure and kill baits is its very low toxicity to other
beneficial insects.
Other traps are also available, such as this one from Bugs for Bugs, which also relies on
pheremones.

3. Chooks to the Rescue!
Poultry are an enormous help in fruit fly control. If you design your orchard to incorporate chooks
they will reward you by turning rotten fruit into eggs and happily spend hours scratching beneath
trees looking for fruit fly pupae. Adult fruit flies are trapped on the ground for up to 24 hours after
emerging from the pupae as it takes this long for their wings to harden. During this time the adult
flies are also vulnerable to a roving chook. Where it isn’t possible to allow chooks free range, small
demountable fences can be used under trees vulnerable to attack by fruit fly.
If you find maggots they need to be accurately identified so that a method of eradication can be
established. Contact your local Department of Primary Industry if you find maggots.
Exclusion Zones
Major fruit production areas such as the Sunraysia and the Riverland are in an area known as the
Fruit Fly Exclusion Zone. This area was established to facilitate exports of their produce to both
other areas of Australia and overseas. There are roadside bins for travellers to deposit any fruit
before entering these areas. There is fruit fly in eastern Victoria and fruit may not be removed from
this area.
Host Plant
Clivia sp. have been found to be a host for fruit fly. Fruit fly lay maggots in the developing fruit, so
spent flower heads should be removed.
Interestingly, horticulture students doing research accidentally discovered this connection!
Contacts for State Government Departments:
Victoria www.dpi.vic.gov.au, 136 186, or free call 1800 084 881
NSW www.dpi.nsw.gov.au
Queensland www.dpi.qld gov.au, 132 523
SA www.pir.sa.gov.au/planthealth, 1300 666 010
WA www.agric.wa.gov.au

4. Image sources::
Top image courtesy of Rural City of Wangaratta
Second image courtesy of Department of Agriculture & Food WA
Trap image courtesy of www.greenharvest.com.au