Pachnoda marginata Larvae (x5)

This is a pack of 5 Pachnoda marginata larvae. Beetle larvae look nothing like the adults they become. They're white, C-shaped grubs with a brown head capsule and six small legs near the front. They spend their entire larval life underground, eating substrate.

Larvae go through three size stages called instars: L1 (tiny, just hatched), L2 (mid-sized), and L3 (full-sized, fat, and ready to pupate). We ship a mix depending on what's available, but most will be L2 or L3. The total larval period for P. marginata is around 3-6 months depending on temperature and substrate quality.

When a larva is ready to pupate, it stops eating and constructs a pupal cell from compressed substrate. Inside this cell it transforms into a pupa, and eventually into an adult beetle. The pupal stage lasts 4-8 weeks. This is holometabolous (complete) metamorphosis, and watching a fat white grub turn into a glossy yellow and black beetle is genuinely one of the best things about keeping beetles. The whole process from larva to adult emergence takes around 4-7 months, so you won't be waiting long.

Substrate. This is the single most important thing. Larvae eat their substrate, so it must be fermented hardwood flake soil made from deciduous wood (oak, beech, or similar). Do not use regular potting soil, compost, coco coir on its own, or anything containing softwood (pine, cedar, spruce). Softwoods contain phenols that are toxic to beetle larvae. If you can't source flake soil, well-rotted deciduous leaf litter and crumbled white-rotted hardwood will work, but proper flake soil gives the best results.

Container. Give each larva roughly 1 litre of substrate. For 5 larvae, a container holding 5-6 litres with a substrate depth of at least 15cm works well. You can keep them together at this density, but if they start surfacing regularly it may mean they're running out of food or space. Top up or separate them if this happens.

Temperature and humidity. Keep at 22-26°C. Slightly cooler than the adult range, and more consistent, produces the best results. The substrate should feel damp when you squeeze it but no water should drip out. If it dries out, the larvae dehydrate. If it's waterlogged, they drown or develop bacterial infections. Check moisture every week or so and mist the surface lightly if needed.

Feeding. Larvae don't need any food beyond the substrate itself. They eat the fermented wood. You'll notice the substrate gradually turns into dark, fine frass (droppings). When more than half the volume looks like frass rather than flake soil, it's time to replace or top up the substrate. Gently sift through to find the larvae, move them to fresh substrate, and discard the spent material.

Pre-pupation and pupation. When a larva is getting ready to pupate, it stops moving, turns slightly yellow, and may shrink a bit. It will build a hard-walled pupal cell from compressed substrate. Once this starts, do not dig through the substrate. Do not open, poke, or squeeze the cell. A broken pupal cell usually means a dead or deformed beetle. Leave the container undisturbed for 6-10 weeks. The adult will dig itself out when it's ready.

For more detail, read our Pachnoda marginata care guide.

Each larva is packed in its own individual cup of moist flake soil substrate. The cups are ventilated and cushioned inside the outer box. This keeps the larvae separated during transit so they don't stress or injure each other.

We ship via tracked next-day delivery, Monday to Wednesday, to avoid weekend delays. In cold weather we add a heat pack. In extreme heat we may hold your order and contact you before dispatching.

When your larvae arrive, open each cup and check the grubs are alive and moving (give them a few minutes to warm up if the parcel was cold). Transfer them into their prepared substrate as soon as possible. Don't leave them in the shipping cups long-term as the small volume of substrate won't sustain them.

All live orders are covered by our live arrival guarantee.