Dealing with Fruit Flies

Dealing with Fruit Flies

Fruit Fly Metamorphosis

Photo Credit  Orkin

Fruit flies undergo three stages of development before emerging as adults: egg, larva and pupa. At room temperature, fruit flies can develop into adults within one to two weeks. The egg and larval stages span approximately eight days, while the pupal stage lasts six days. The adult fruit fly lives for several weeks.

Twenty-four hours after a female fruit fly lays her eggs, larvae hatch. Fruit fly larvae undergo moulting stages known as instars, during which the head, mouth, cuticle, spiracles and hooks are shed. During the larva’s third instar, it crawls to a drier area to pupate. The pupa case is formed from the larval skin as it darkens and develops a hard surface.

Fruit fly adults develop in this pupal stage. Twenty-four hours before the adult emerges, the pigmentation of the eyes and the folded wings are already visible through the pupal case, called the puparium. The pupa darkens just before the adult fly emerges.

When metamorphosis is complete, the adult fruit fly pushes its way through the anterior end of the puparium, known as the operculum. Initially, the fruit fly is light in coloration, with expanded wings and an elongated abdomen. Within a few hours, the fruit fly darkens, extends its wings and expands its abdomen.

Approximately 48 hours after emerging from the puparia, female fruit flies are sexually mature and can begin breeding and laying eggs. Adult fruit flies are fertile for the entirety of their life spans. Female fruit flies can store sperm from multiple inseminations for use in future egg productions.

(Article Credit Orkin)

 

How To Make A Fruit Fly Trap

Once fruit flies show up, it can be hard to get rid of them.  Western Australia used to be able to pride itself on being fruit fly free but no more.

All it took was one person to smuggle an infected fruit across the border from the east coast and hey presto, we very quickly also became infected with fruit flies here.

In orchards or even just your fruit trees in the garden, the larvae will travel down the trees when they have feasted enough, to go into the ground or under cover so as to pupate and turn into adult flies.

Treatments

Around the House:

Take a glass, or bowl, or some kind of dish, and fill it with apple cider vinegar (or white vinegar). Place a piece of fruit in the dish (I use frozen strawberries or mangoes), and put a drop of dishwashing soap in it. Put these in all of your problem areas. I keep one near the fruit bowl, and one near the vegetable scrap bucket, and one near the trash can.

Around the Garden:

You can also cut a section out of a plastic fizz bottle about half way up (just before it starts to for the shoulder and neck of the bottle) and place these ingredients into the bottle and then hang the bottles in your fruit trees by tying a string around the bottle neck. Once it rains you might need to replace the contents.

The fruit and vinegar attract the flies, and the liquid soap keeps them from being able to fly out of the liquid once they've landed on it. The result is that they drown and die which ends the breeding cycle.

IF the infestation is heavy then you will need to repeat this a few times, and possible over a few years. You will need to remember also, that you won’t just be dealing with the fruit flies that have been breeding at your place, but also all the ones that come to feast on your fruits from the surrounding neighbourhood also.

This can be, and is extremely frustrating but if you continue with the treatment, then eventually fruit flies will be wiped out for good. It is however a long slow process.

Check your traps once a week and if the body count is heavy, then clean out the traps and restart them.

Fruit flies are most prevalent from spring through to autumn, so you will need to lay the traps throughout this time to ensure that you make the greatest impact on killing them.

Another method deals with attacking the larvae as they migrate down the trees to go into hiding to pupate.

This involves spreading a 2 inch wide (5 cm) strip of petroleum jelly (Vaseline) around the trunk of the trees and placing a width of corrugated cardboard (the one with the corrugated iron looking formation between two sheets of thinner cardboard), several lengths longer than with go around the tree. You want it to go around at least twice and which, has also been spread with the petroleum jelly (Vaseline). With the petroleum jelly side to the tree, wrap it around firmly but not too tightly and secure in place with string. Check and replace each week until winter comes. Burn the cardboard that you remove so as to kill all the pupae and any remaining larvae that may be present.

This method will also aid greatly in dealing with the dreaded codling moth that attacks apples.

The cardboard fools the larvae into thinking it has reached the ground and they pupate in the crevices in the cardboard which makes it very easy to discard them

It's simple, cheap, and chemical free!

Here are a few other tips for killing fruit flies:

1. Alcohol also attracts fruit flies and especially things like beer and wine.

Around the patio, in the kitchen etc., put a small amount of red wine (the dregs from the bottom of the bottle are fine for this) or stale beer into a shallow dish, cover it with plastic wrap, and then poked a hole into it. This will need to be changed every couple of days.

2. I grow tomatoes, and I have found a great way to trap the flies when ripening the fruit inside. This will also work if you can place them somewhere so that rain does not enter the traps.

To trap the fruit flies:  Take a 600 ml or bigger fizz bottle (soda bottle for the non-Aussies!) and cut it in half, round ways about a third of the way down from the top. Put an old tomato or some fruit in the bottom of the bottle with a small amount of water. Take the top third of the bottle without its lid on and turn it upside down. Then place it into the bottle (like a funnel). The flies can fly in, but don't make it back out again! For hanging this version, you could use a small onion bag to cradle the bottle for hanging because the fruit flies will still be able to gain access to the bottle or make up a  string cradle to hang them in.

3. Here is a very, very old remedy for fruit flies but this one I have not as yet tested to see how well it will work. If your infestation is really bad then anything is worth trying.

Fruit Fly Eliminator

1 pint milk

1/4 lb. (125g) raw sugar

2 ounces (50g) ground pepper

Combine all ingredients in a saucepan and simmer for 8-10 minutes over a gentle heat. Pour the mixture into shallow dishes. Flies attack it greedily and soon suffocate. You could also use this mixture in the hanging bottles I described above and hang them in your trees or on your trellises where the tomatoes are growing and even in your polyhouses, glass houses etc.

This recipe was traces back to around 1850.

4. This next tip came from a friend that worked in a laboratory researching fruit flies but this method is restricted to inside or undercover use only and not suited to open areas due to the use of the paper funnel. If you can improvise on that though then it would also work. Maybe, by drilling about a 5 mm (at most) hole in the top of a fizz bottle lid and using this as described earlier would suffice.

Use bottles partly filled with beer or another sweet liquid, with a paper funnel taped to the top to capture stray fruit flies. Make sure that the funnel opening is large enough for the flies to enter, but not too large that they can easily fly out. Also ensure that the end of the paper funnel is well away from the liquid in the bottle.

The flies are attracted by the sweet smell of the liquid, but aren't smart enough to escape the funnel. Once the bottle is filled, you can empty the contents, rinse out and start again with a new paper funnel.

©Karma Barnes