There are supplemental live foods that you can (an should) offer your dart frogs such as springtails (wood lice), flour beetle larva, dwarf (white or purple) isopods, pin head sized crickets, black soldier fly larva (small Phoenix worms), termites, bean beetles (black eyed bean weevils), pea aphids to name a few insects that can be cultured and of appropriate size and considered adequate foods. These foods though are to be "supplements" to fruit flies. Thus they serve to add a varied diet but not to replace fruit flies. *Anything insect wider than the length of the space between a frogs eyes is a choking hazard. Thus feed insects smaller than that "eye to eye" size.
We discourage feeding outdoor caught insects as this introduces risks to expose your frogs to parasites, chemicals that the insect was exposed to (fertilizers, herbicides, pesticides, unknown ingested material), etc.
Unlike many other animals we recommend not replying on "others" such as pet stores to provide your frogs food. Even if you had a reliable resource (which is rare) you would spend a pretty dime in doing so. A culture store bough might run you $6-14 before shipping. A purchased culture will only last a few weeks before it needs to be discarded before it "crashes" (stops producing) or becomes inundated with mites. Unlike other animals there is no flake, pellet or other commercial "off the shelf" food product available for dart frogs. Consider creating your own fruit fly cultures.
Notes on feeder insects:
Melanogaster flightless wingless fruit flies:
Drosophila Melanogaster are the smallest fruit fly and best for young frogs and small dart frog species. A culture of them takes about 12 days to start producing new flies.
Hydei winged though flightless fruit flies:
Drosophila Hydei are a little larger flightless fly with wings that takes about 16 days to culture. These are ideal for your larger dart frogs as they have a little more meat on their bones per say. Ideal for larger frogs. They produce slower with too much vinegar in their media. In hot conditions they can slowly gain the ability to fly.
Golden Hydei winged/ flightless fruit flies:
Golden's are a a little bit larger flies than Melanogaster flies with the benefit of breeding faster than Hydei. Clutch sizes seem larger than Hydei too. They are our favorite fruit fly. They also seem to produce longer than Melanogaster cultures as well. Also ideal for larger frogs.
Turkish Gliders fruit flies:
Turkish Gliders are larger than Melanogaster and smaller than Hydei. Their production rivals Melanogaster thus having a quick producing larger fly is ideal it has a fairly big less than ideal quality in that they glide. They have wings and although most dont fly they will take to the air and glide. When transferring flies while dusting or feeding you may not like the fact that they are very mobile and dont go where you want and are prone to getting out while feeding. We stopped using Gliders as a result.
There are other types of fruit flies out there, however the above Melanogaster and Hydei are the preferred flies of choice that are very prevalent in the dart frog community.
Size to purchase: "Pin head" sized. A note on crickets, if allowed to roam free in your vivarium crickets will eventually eat and damage plants. As crickets grow are capable of biting and harming frogs. Although crickets are generally available in many pet stores, finding a stable supply of appropriately sized crickets (pin head) sized crickets is unlikely, do not buy "small" or larger crickets as they are unlikely to be consumed by your frogs.
Bean beetles contain chitin that is tough to be digested and can cause (stool) impaction. Thus beetles should be fed sparingly to darts. However they are perhaps the easiest insect to culture. All you need is a cup with several inches of black eyed beans with a vented lid. The beetles will eat a hole in the bean and lay eggs. You can use a large sifter to separate beetle from beans. Take note that bean beetles can fly. They warmer the air temperature the more likely they can take flight when opening the culture. This is a perhaps the biggest disadvantage to feeding bean weevils. However keeping a few cultures on the shelf may be invaluable if your fruit fly cultures crash.
Rice Flour beetle larva:
Rice flour beetles are fairly easy to cultivate. Frogs though find the beetle itself distasteful. Luckily they produce a good quantity of larva which frogs will readily eat. These are a good resource for adding weight onto frogs. All you need to do is have a culture of a couple inches of brown rice flour and white rice flour with added nutritional yeast. Add a few rice flour beetles and larva will be produced in a few weeks. Every week or more add a pinch of nutritional yeast into the flour to keep your culture going. Note that air moisture can cause the flour to harden and kill off the beetles and lava. Having a solid airtight lid is a must. Feeding out larva is the most difficult aspect. You will want a flour sifter to separate the flour from the beetle shed, larva and beetles. The shed can be blown off must is messy. You will want to set the sifter aside and wait for the beetles to leave then place the larva on a feeding dish. This is time consuming. Great though for froglets and under weight frogs.
Phoenix worms aka black soldier fly larva are another good feeder supplemental food. They are available online and some pet stores. We recommend monitoring larva when fed. We do not allow the larva to escape to freely roam into the vivarium. We place larva on a petri dish to feed out. When the larva mature (pupate) they turn into black soldier flies. They look like a wasp and larger than a house fly (but are harmless). Not something most of us want flying around your vivarium or home.
Feeding fruit fly larva:
You can feed the larva of fruit flies to your dart frogs. Frogs that are young, thin or ill can benefit from the fatty fruit fly larva. You can scrape larva right out of a culture. Or you can place a culture as a larva feeder within the vivarium (especially when going on vacation for a few days). Just cover a culture with something like screen door mesh placed over your culture. Place the culture on its side in your vivarium. Larva will soon crawl out into your vivarium as the eggs hatch. Thanks Sabrina R. for that tip!
Culture fruit flies
To raise Dart Frogs successfully we encourage you to culture fruit flies at home. A few factors that can cause culturing issues include temperature, mold, humidity, mites and even complaints from family members (odor from vinegar). Before you purchase dart frogs you will want to practice culturing fruit flies until you are successful. Otherwise you might find yourself scrambling for a place that sells fruit flies in time to keep your frogs fed and have hungry frogs waiting and waiting.
Keep an eye out for frogs that have a tough time eating in the presence of other frogs. If frogs are not eating enough and a peer is getting the lions share you may need to separate the struggling frog into another enclosure.
Sticky tongue syndrome. If you have a frog that flicks his tongue but cannot capture prey it may be a sign of a vitamin deficiency. Providing food items with Vitamin A may help address symptoms of STS.