Pachnoda marginata
The sun beetle. Vivid yellow and black, active by day. Hard to beat as a first beetle.
About Pachnoda marginata
Pachnoda marginata, the African flower beetle, is a medium-sized scarab from West and Central Africa. Adults are unmistakable: bright yellow with bold black markings and a glossy sheen that catches the light. They're diurnal (active during the day), so you actually get to see them doing things.
The full life cycle, from egg to adult, takes around 6–9 months under good conditions. Adult beetles typically live 3–6 months, during which they feed, fly, and breed readily.
Larval care
The larvae (white C-shaped grubs) spend their entire development underground. They need a deep, nutrient-rich substrate to feed on and eventually pupate in:
- Well-rotted deciduous wood as the main food source
- Mixed with coco coir to hold moisture
- Substrate depth of at least 15 cm
- Keep consistently moist. Never let it dry out
Substrate compaction matters. Larvae need firm enough material to construct a stable pupal cell. Loosely packed or overly fluffy substrate can cause pupal cells to collapse, which is often fatal. Gently press the substrate down when setting up the enclosure.
If you are raising multiple larvae together, separate them if conditions become crowded. Competition for food and space can slow development and lead to smaller adults. A good rule of thumb is one larva per litre of substrate.
Larvae will pupate inside a soil cell they construct themselves. Do not disturb the substrate once they stop moving, as this signals pupation has begun. The pupal stage lasts 4–8 weeks.
Adult enclosure & feeding
Adults need a well-ventilated enclosure with room to fly and climb. A 40×30×30 cm box works well for a small group. Provide cork bark and branches for climbing and resting.
Adults feed almost exclusively on sugary foods:
- Ripe fruit: banana, mango, peach, fig
- Flower petals: roses, hibiscus, dandelions
- Beetle jelly (widely available, clean and convenient)
Replace fresh food every 1–2 days. Overripe fruit is fine. They're attracted to fermenting sugars. Remove any mouldy food promptly.
Breeding
P. marginata breeds readily at 24–26°C with a moist rotted wood substrate. Females burrow down to lay eggs a few centimetres below the surface. Eggs hatch within 2–4 weeks into tiny larvae that immediately begin feeding.
A single female can lay 20–40 eggs over her lifetime. If you want to maximise yield, provide a separate breeding container with a deeper substrate (20+ cm) so females have plenty of undisturbed space to lay.