Fly Update.

Mike Fidler

There are a few things I left out of the fly video on the Naturally for Birds TUTORIAL page which I need to update, including overcoming some of the problems you may encounter.

Apparently, there are more than 10,000 species of fly in Australia but obviously only a few are likely to be suitable for culture as a food source for our birds.

Some I am aware of are fruit flies, soldier flies, bush flies, house flies, blow flies, blue bottles. I know some aviculturists in Tasmania breed a local fly which does not need heat, at least in the summer, and there must be more fly species we could use we are just not aware of.

During the warmer months you can create a smorgasbord of fly maggots by putting a container of the house fly formula outside in a warm spot. When I did that I had loads of different species of flies laying their eggs in the mix. I had no idea what most species were, but it created a mix of different sized maggots which the birds wolfed down.

If you can’t cadge a starter stock of pupae off a mate, this might be a way to start up your own fly breeding programme. I haven’t tried it, but it could be fun to have a go. I might give it a try next summer!

So, if you are going to breed flies you need to work out what is the best diet for the species you have and also the best temperature to keep them in to maximise production.

The ones I keep are bush flies. I have tried a few other species but I find the local bush fly we have in NSW is the easiest to keep. As I have said in the Naturally for Birds TUTORIAL video, 1 part pollard, 1 part chick crumbs and one part water is the only diet they need to thrive.

When I tried keeping house flies, I found I had to include milk powder. I found 1 part pollard, 1 part milk powder, 1 part chick crumbs and 1.5 parts of water worked OK for me.

Some people who keep house flies do a mix of bran and milk powder, which seems to work OK, but seemed at least to me, a lot smellier!

WARNING – the one thing I would suggest is don’t be tempted to use the meat eating flies, like blow fly.

If you do, you have to make sure there is absolutely nothing left in their maggots gut before you feed them to your birds otherwise you are at great risk of botulism which kills the birds within hours. I lost a lot of birds before I learnt this the hard way, so now I won’t touch meat eating flies with a barge pole.

 True or false I am not sure, but I picked up somewhere that flies are more nutritious than their maggots. So for a long time I used to put all waste pupae and maggots from the birds into a plastic box with a 2cm hole in the lid and put a stick poking down to the bottom. As the flies hatched, they would climb up the stick and there was always a bird sitting on the top waiting to gobble them up.

But then Ian Brown invented a far better, and more controlled way, so now loads of us have converted to that. For details, go to the Naturally for Birds TUTORIAL page.

 We allow the maggots to turn into pupae and then put them in Ian’s container to feed to the birds.

 As usual, once someone launches a new idea it only takes a short while for other people to modify it. Sometimes as an improvement and sometimes just because it suits them.

I have modified the container that Ian uses slightly and have filched the Bruce Hockley idea of hatching the flies in a modified fast food container before releasing them into Ian’s feeder.

Breeding your own flies really is quite simple, however even the easiest things in life usually have a few problems, so below are a few of the more common ones.

1: p. Not getting many maggots. 

    a: Not enough breeding age flies. You have to put pupae in your fly box every 4 days to keep a mature breeding population.

Old flies don’t breed, young flies don’t breed, mature flies lay eggs every third day, so you might think you have enough flies, but if they are the wrong age mix, they don’t lay eggs.

Gary Fitt has added the following information:

Young flies don’t mate until 3 days after emergence. Each female matures eggs in batches of between 20 and 40 eggs (depending on her body size) and will lay 4 to 5 batches in her lifetime depending on temperature and nutrition. It takes them roughly 2 days to mature each batch of eggs, so female needs to live at least 13 days to have maximum fecundity

2: p. The fly food medium is lumpy and dry on top making it hard to feed out to the birds.

    a. You either don’t have enough maggots or you have given them too much food. So either increase the maggots or decrease the amount of food.

 It does help if you turn / crumble the food in the containers in the fly box every day. It allows the maggots to move freely through the medium and turn in the dry bits on the top so it gets eaten.

3: p. The maggots are very small and thin.

    a. Either, you have not put in sufficient water and the medium is too dry. [ don’t put too much water in or you may make the medium slushy and could drown the maggots]

Or, you have not put in sufficient food.

Gary Fitt covers his solution to this problem in TUTORIALS on the Naturally for Birds web site.

4: The biggest problem I have noticed in inexperienced fly breeders is that they don’t have sufficient flies in their breeding boxes. It needs to be HEAVING!

I know it sounds counter intuitive, but the more flies there are in the breeding box the easier it is to look after them.

Each female fly lays approximately 30 to 40 eggs at a time, so if you only have 2 breeding age females in their you will only get 60 odd maggots. So now you can do your own math!

5: Comments rather than solutions to problems:

a. I have noticed on a number of occasions people who are having trouble producing enough maggots for their birds are prone to feed what they have to the birds because they don’t want to take the risk of the birds deserting their young.

The only problem with this approach is that it prolongs the pain of the problem. It is a bit like the solution to item 4:, if you only put 2 pupae in the fly box you will only get 2 flies, which in turn will only produce very few maggots

b. The other thing I have noticed with people who have constant fly problems is that they are somewhat haphazard in the timing of putting in new pupae. Once you have only a little experience, flies are easy and don’t take much looking after; BUT, if you want to avoid big fluctuations in your maggot productivity, you have to be meticulous about replenishing pupae every 4 days.