How many fruit fly cultures for your frogs?

How we calculate

• Cultures to start per week = small frogs × 0.33 + medium × 0.5 + large × 0.75 + juveniles × 0.25, × 1.3 if you breed hydei, plus your “extra” cultures. Rounded up, at least 2 cultures.
• Cultures producing = cultures per week × 2.5, rounded up (one culture produces for 2–3 weeks).
• First flies = 12–14 days (melanogaster) or 17–22 days (hydei) at 22–25 °C, × 2.2 below 17 °C, × 1.6 from 17 to 20 °C, × 1.25 from 20 to 22 °C, × 0.85 from 25 °C, rounded. Above 28 °C, no production.
• Per meal = 5–10 flies per small frog or juvenile, 10–20 per medium, 20–40 per large. Half as many (rounded up) with hydei, which are bigger.
• For each culture = 50 to 75 flies to seed it.

Example

6 medium frogs, melanogaster, at 21 °C. Cultures = 6 × 0.5 = 3 per week. Producing: 3 × 2.5 = 7.5, so ≈ 8 at once. At 21 °C the delay is × 1.25: ≈ 15–18 days before the first flies. Per meal: 10–20 flies per frog.

Sources: Josh’s Frogs (melanogaster and hydei timings, 24–26 °C), keeper forums. These are guidelines: adjust to your frogs’ appetite.

Frequently asked questions

How many fruit fly cultures per week?

For 2 medium frogs, the calculator gives 2 cultures a week: that is the minimum, so you never run out.

How long until a culture produces?

About 12 to 14 days for melanogaster and 17 to 22 days for hydei at 22–25 °C. It takes longer when it is colder.

What temperature for the cultures?

22 to 26 °C. Above 28 °C the males become sterile and the culture stops producing.

Melanogaster or hydei?

Hydei are bigger: you need half as many per meal, but they are too big for small frogs and froglets.