I know this thread's a few weeks old, but I thought I'd add some stuff!
Flightless fruit flies are actually a lot easier and cheaper to get than you might think. =) They're also extremely easy and cheap to maintain.
I build dart frog terrariums as a hobby, and dart frogs are some of the other pets I keep (besides finches). Here's a picture of one of my tanks:
Because the frogs eat fruit flies I culture them myself. Setting up a single culture takes approximately five minutes, and after about two weeks that single culture will produce hundreds of flies daily and last up to a month and a half. Forget those little tubes! Fruit fly cultures should look like this:
You can also use typical canning/Mason jars for them if you want to be environmentally friendly. When the cultures die, scrape out the goop, wash them, and viola! Ready to reuse.
If you want to get all the supplies for culturing fruit flies from one place for a really great price online, you can check out
http://www.joshsfrogs.com/ or
http://www.neherpetoculture.com/. Both are reputable vendors among the dart frog community (froggers have a forum just like this one, with just as much chirping -- frogs sing too!) and provide great service.
Don't want to culture your own bugs? No problem! Both of the sites above offer producing cultures, already prepared so all you have to do is open the lid and feed the flies out. You can also buy producing cultures at your local Petco sometimes. They'll be in the reptile section and will look like this:
They're about $10 apiece. They'll last you around a month or so if you get them fresh. =)
But you're probably wondering, okay, sure, is feeding my finches really worth having flies all over my house?
Fear not! There's a way to keep the flies from getting everywhere. They have a hard time climbing slick surfaces. They have an even harder time climbing slick surfaces when they're covered in calcium powder.
Here's my process:
1) Tap flies from culture into a slick cup.
2) Dust flies with calcium powder. Make sure the powder you're using is avian-safe!
3) When flies are coated with the white dust, tip them into a shallower cup or bowl. Again, make sure the cup or bowl has slick sides.
4) Put the cup/bowl in the finch cage. I clip mine down so it won't tip over when the finches perch on it.
5) Watch the finches gobble up the flies like it's Christmas and the cookies are fresh out the oven. =)
I hope this helps anyone who's interested in trying out flies for their birds. I have lots of experience with flies, so if anyone needs help with them, please ask... I don't know much about birds yet but I do know my bugs. =)
Also, if anyone wants to try out flies and lives within a few hours of central NC, just let me know. I'd be happy to offer over a culture, no charge.
Best,
Ash