Fruit Fly Management in the Home Garden

Fruit Fly Management in the Home Garden
Colin Bain
11 January 2017

Fruit Fly Management in the Home Garden

5-tn.jpgIn Australia there are some 80 species, 7 of which are considered to be of economic importance and of these Queensland fruit fly (Bactocera tryoni) and Mediterranean Fruit Fly (Ceratitus capitata) are the most wide spread.

Queensland fruit fly (QFF) attack a wide range of fruits and fruiting vegetables, leaving them inedible. Australia’s Plant Biosecurity Cooperative Research Centre last year estimated the cost of fruit fly at A$300 million a year in control and due to lost markets, that does not include the potential of growth in the industry.

Fruit matures at different times of the year so QFF activity is not strictly seasonal.

The QFF lifecycle is relevant in monitoring and control :

Adults become active – Males band together and release sex pheromones to attract females

Egg-laying – Female QFF lays her eggs in the fruit with her “stinger” – sting marks on the fruit surface

Larvae (maggots) in fruit – Eggs hatch within a minimum of 24 to 48 hours. Larvae grow in length from about 2mm (first larval instar stage), through 5mm (second larval instar) to 8 to 10mm (third larval instar) in fruit over a minimum of 7 days up to 40 days in cool weather and then jump out of the fruit.

Pupae – After leaving the fruit the larvae become pupae and stay in the ground or mummified fruit – for a minimum of 10 days up to about 20 days in cool weather. After a minimum of 10 days the adult fly emerges from the pupal case. The fly develops within the pupa and then bursts open the pupal case and then tries to find a food source.

Following its feed the Flies mate and each female then flies off in search of ripening fruit which she punctures and lays her eggs. It takes one to two weeks for the flies to mature, mate and lay more eggs.

The average adult fly lives from 2 to 4 months, one mated female could produce 400 female and 400 male offspring in her life time. And round and round the cycle goes!

The home gardener can be devastated with damage to their fruit and vegetables, however they also play an important part for the overall control of Fruit Fly in Australia. Home gardeners in all areas have a vital role in controlling QFF and preventing it from spreading. By caring for your fruit trees, disposing of fruit properly and reporting suspected detections of QFF, you can protect your home-grown produce and help reduce the economic impact of this pest.

With all of the above factors taken into consideration Bio-Trap Australia have developed the following products for both domestic and commercial use:

Bio-Trap V2X – Yellow base with a clear top, this has proven to be the best combination as Fruit Flies are attracted to the yellow base and less inhibited in entering a trap with a clear top. Holes facing upwards, this serves several purposes: reduces water entry into the trap, easy fly entry and improved release of vapours from the attractant.

Biotrap Fruit Fly Attractant Gel – a non hazardous, safe to handle gel designed to be used in conjunction with the Biotrap V1 trap and has proven to attract both the male and female fruit fly but generally higher numbers of the female are attracted particularly at fruit ripening. They will be attracted when they emerge from the pupal case in search of food. This a great time to catch them, before sexual maturity. They will also be attracted as sexually mature adults.

DDVP (Dichlorvos) cubes – TRAP TOXICANT
Bio-Trap has registered for use in Australia DDVP (Dichlorvos) cubes, these are 15mm (1.47g) cubes these are used in conjunction with the relevant lure to provide quick and effective knockdown of the insect on entry to the trap.

For domestic or backyard use install one Bio-Trap V2X trap for every 15 sq. meters, place traps in trees exposed to early morning sun. Squeeze 50-60 mL of Bio-Trap Fruit Fly Attractant Gel into the base of the trap, add one Biotrap DDVP cube and place the trap within the tree preferably on the eastern side at a height of approximately 1.5 meters. The trap should be inspected weekly to monitor fruit fly activity particularly in the fruit bearing period. Replace or replenish traps with the GEL & cube every 3 months.

Don’t trap or bait just at harvest time – trap and bait BEFORE & AFTER HARVEST – this will stop fruit fly numbers building up at harvest or by next season’s harvest.

If you can, get your neighbours on board as Fruit Fly have no boundaries!

Bio-Trap Products (pdf)