We have started harvesting our tomatoes. It’s a lovely feeling to see them sitting there red and glowing in my fruit bowl waiting to be popped on a sandwich or tossed in a salad.
Sadly, they’ll be tossed in a salad of bought lettuce as the rabbit squeezed into the vegie garden and devoured all my lettuce and salad greens.
These tomatoes however were planted in the garden rather than the vegie plot. So far they’ve not only evaded ‘wascally wabbits’, but they’ve also avoided the dreaded fruit fly.
I don’t take chances with fruit fly and, if you are living in Queensland, New South Wales, the Northern Territory or Western Australia, neither should you. Fruit flies are a very real menace for any soft fruits growing through spring, summer and into autumn.
Along the east coast we have the Queensland fruit Fly, a native pest, but in Western Australia it’s the Mediterranean fruit fly (the Medfly), which is the pest and it’s also found in many other parts of the world.
Female fruit flies lay their eggs in the skins of soft fruits such as tomatoes. The eggs hatch as maggots (small white grubs) that feed in the fruit. As they feed, the fruit rots and if it is not disposed of, it falls to the ground where the maggots finish their life cycle to emerge as adults and continue the assault on our crops.
Controls in the past were mandatory and involved chemicals such as Rogor and Lebaycid. The removal of these products from the home garden market however has made room for other approaches to fruit fly control.
I am using a chemical lure called Eco-Naturalure to keep the fruit fly away from my tomatoes. I mix up the bait then paint it on stakes in the tomato bed. To protect it from the weather, I pop a container over the top of the stake.
The bait needs to be reapplied frequently particularly after rain or a heavy watering. This is not a ‘set and forget’ control method.
Baits and lures to control fruit fly have been around for a long time, but the newer baits are different. Old style Dak.Pots and Eco-Lure Fruit Fly Traps, for example, attract male fruit fly. They use pheromones to do this. They are useful to monitor for the presence of fruit flies and offer some control.
Eco-Naturalure (click here for more information on this product) however targets female fruit flies with a mixture of protein attractants and insecticide. Another product that works this way is Nature’s Way Fruit Fly Control from Yates.
To keep these lures low toxic and organic the insecticide in them is spinosad, which is based on naturally occurring soil bacteria. The baits are very clever and their success relies on knowledge of how the female fruit fly’s life cycle works. They require a protein feed before egg laying. The bait contains proteins and sugars that attract the female fruit fly, who then takes in the insecticide as she feeds ensuring she dies before laying any eggs.
As a back up I also have exclusion bags that can fit over trusses of fruit. These allow the fruit to ripen, but keep out the bugs. The exclusion bags I use came from Green Harvest.
They’ll deter birds too – well, most birds. One year I did witness a large crow open an exclusion bag and feast on some particularly large red tomatoes that I was on the way to the vegie garden to harvest. He perched on the top of the tomato stake and had a jolly good feed!
If all else fails, pick your fruit as soon as it begins to colour with a small piece of stem attached. Bring it indoors to ripen out of reach of fruit fly and birds. But if you do get fruit fly in your fruit make sure you pick up all the affected fruit, put in a bag – a plastic bag – and let it stew in the sun for a few days to kill the larvae. Then bury it or put it in the rubbish bin (not the compost heap).
This way you’ll help break the life cycle and reduce the numbers of this particularly irksome pest.
Unfortunately fruit fly lures don’t work on rabbits so I am headed back out to my vegie patch to see just where the rabbit got in last night and to add more wire and stakes to the perimeter to keep him and his friends and relations away from my new lettuce plants.