Fruit Flies: A Nose For Trouble

Home fruit trees like citrus, mango and avocados are irresistible to fruit flies. Unfortunately, once they arrive, they’re extremely difficult to get rid of!

Summer is pest season, but when your home orchard starts fruiting and you notice a distinct increase in flying pests, the chances are good that they’re Fruit flies. These small insects have a powerful sense of smell and move from one host to another as fruit appears.

Find them (almost) anywhere

Three species of Fruit flies are widely distributed in southern Africa – they’re commonly known as the Natal fruit fly, the Mediterranean fruit fly and the Mango fruit fly. They are found on a wide range of cultivated crops and plants, as well as wild plant hosts, and they love our warm climate. You might even notice them hanging around your wine or beer before you see them in the garden!

Fruit flies do extensive damage

If there’s a pest that causes a common reaction of horror amongst commercial, small scale and backyard gardeners, it’s the fruit fly. Not only do they cause extensive damage, but they are particularly hard to control too.

In South Africa, fruit flies are most active in high summer, from January to March, when females deposit their eggs under the skin of ripe or ripening fruit. The larvae feed on the fruit, tunnelling to the centre of the fruit and causing it to decay.

Commercial farmers take monitoring for and managing fruit flies extremely seriously. Fruit flies are an important quarantine pests , if left uncontrolled, can destroy an entire crop. In home gardens where no controls are applied, it is common for 80% of fruit to be damaged.

Managing fruit flies in your home orchard

Here are a few tips to keep fruit flies at bay this summer:

  • Make sure you’re keeping an eye out for them at least two weeks before you expect your fruit trees to start fruiting.
  • Clear away alternative host plants (such as wild growing guava), which can serve as a breeding ground. Remember, they’re hosted by a large number of plants and will move to your fruit as soon as they smell it.
  • Keep your orchard clean. Collect and destroy all fallen fruit from the ground. This can reduce fruit fly numbers by preventing the pupation of the maggots in the soil. 
  • Controlling fruit fly is best done by breaking the breeding cycle. Using the E.G.O. PheroLure® from Insect Science, along with a McPhail trap, attracts males to the trap and prevents them from mating and starting a new generation. Traps should be placed in your home orchard before the fruit ripens. If you’re using them for your veggie patch (they love things like Blackberries, blueberries, peppers, strawberries and tomatoes), place the traps one week before germination or transplanting.
  • Hang the trap in the top third of the fruit tree.
  • The traps should be inspected weekly on the same day of each week and the number of fruit flies caught in the trap should be recorded.
  • Clean the trap bucket of dust and foreign matter regularly, even if no flies have been caught.
  • Replace traps every 20 weeks.

Visit https://insectscience.co.za/pest/fruit-flies-mango/ and https://insectscience.co.za/pest/mediterranean-fruit-fly-and-natal-fruit-fly/ to find out more.

The Gardener