Flower beetles, rhinoceros beetles, stag beetles: litres of substrate per larva, container size, how often to change it and time to pupation, by species, instar and temperature.
| Species | Substrate / larva | Keeping | Larval duration |
|---|---|---|---|
| Cetonia aurata | 0.8 L | in groups | 8–14 months |
| Dorcus titanus | 2 L | separately | 8–14 months |
| Dynastes hercules | 10 L | separately | 12–30 months |
| Eudicella gralli | 1.5 L | in groups | 5–7 months |
| Goliathus goliatus / orientalis | 2 L | separately | 5–7 months |
| Mecynorhina polyphemus / torquata | 3 L | separately | 6–12 months |
| Megasoma elephas | 10 L | separately | 18–30 months |
| Oryctes nasicornis | 3 L | in groups | 8–24 months |
| Pachnoda marginata | 1 L | in groups | 3–5 months |
| Prosopocoilus sp. | 1.5 L | separately | 6–10 months |
| Xylotrupes gideon | 3 L | in groups | 5–8 months |
Average values. Males of large species often need more room than females. The stag beetle (Lucanus cervus) is protected in several European countries (Habitats Directive, Annex II); the hermit beetle (Osmoderma eremita) and Rosalia longicorn (Rosalia alpina) are strictly protected, including in France. Never take larvae or occupied dead wood from the wild.
10 L2 Pachnoda marginata larvae at 24 °C. Per larva: 1 L × 0.4 = 0.4 L. Total: 0.4 × 10 = 4 L, so 1 bin of 4 × 1.2 = 4.8, rounded up to 5 L. Change it every 3 months, so 4 × 12 ÷ 3 = ≈ 16 L per year. Pupation: 3–5 months × 0.7 = ≈ 2–4 months.
Sources: common keeping practice. These are guidelines: males of large species often need more room than females.
An L3 Pachnoda larva needs about 1 L. A Dynastes hercules larva needs about 10 L.
Flower beetles like Pachnoda live well in groups. Stag beetles, Mecynorhina, Goliathus and large rhino beetles must be kept apart, or they bite each other.
When half of it is frass, usually every 2–4 months depending on the instar. Keep a little old substrate for the bacteria.
From a few months for Pachnoda to 2 years or more for Dynastes and Megasoma. Cold makes it take longer.
Write to me: I add requested species and fix the numbers.