Breeding report of Argynnis species

Lepiflow

Overwintering Argynnis Eggs and Young Larvae

These instructions apply to species such as Argynnis paphia and Argynnis aglaja.

Initial Setup

Place the eggs or newly hatched larvae in a small container with fine ventilation holes (for example, a box used for live crickets).

Add a small amount of substrate:

A loose tuft of fibers from a Trachycarpus palm is ideal
Coconut fiber can also be used, but keep it light and airy
Do not use leaves, as they tend to develop mold

Put the eggs or larvae into this container and leave them undisturbed for about one week:

For A. aglaja: at least one week after hatching
For A. paphia: about one week after receiving the larvae

This period allows the larvae to find a suitable place to settle for overwintering (diapause).

Cold Period (Diapause)

After this initial week, place the container in a refrigerator.
The vegetable drawer is usually ideal.

Care during this period:

Lightly mist the palm fibers once per week
Allow the substrate to dry out between mistings

⚠️ Important balance:

If it stays wet → ventilation is too low → risk of mold
If it dries within a day → ventilation is too high

The cold period should last:

6–10 weeks total
10 weeks is preferable, as shorter periods increase the risk of incomplete diapause

After Overwintering

After the cold period, remove the larvae from the refrigerator and transfer them to a rearing setup with Viola (violets), their host plant.

A practical setup:

A small container with palm fibers on the bottom
A few Viola leaves provided in a small florist water tube (e.g., 2cc with rubber cap)
Cover the container with breathable material such as pantyhose for good ventilation

Care:

Lightly mist every other day so the larvae can drink
This becomes less important from the L2–L3 stages onward

Further Rearing

After a few molts (L2/L3), the larvae can be moved to a larger enclosure with live potted Viola plants.

Care of Adult Butterflies

After pupation, the butterflies of Argynnis paphia and Argynnis aglaja will emerge after approximately 3–4 weeks.

Place the adults in a flight cage (around 40 × 40 × 60 cm).
Provide food by offering cotton soaked in a 10% sugar solution.

After a few days, the butterflies will usually mate.

Egg Laying Setup

Once mated, females can be placed individually in a smaller container prepared as follows:

Add a loose layer of Trachycarpus palm fibers
Place a Viola leaf underneath the fibers (not on top)

⚠️ Important:
The leaf must be hidden under the fibers. If it is exposed, females will lay eggs directly on the leaf, which can later develop mold in the refrigerator.
The goal is to have eggs laid on the palm fibers, not on the leaf.

Keep the container at:

23–25°C
Out of direct sunlight (to prevent overheating)

Egg Laying and Feeding

After a few days, females will lay a significant number of eggs.

Feed the butterflies daily with fresh 10% sugar solution
Check regularly for egg laying on the fibers

Lepiflow

See photos