To start the breeding, some eggs are enough. They have a white-yellow color and a size between 1 & 2 mm. They must be kept in a small box with a lightly moisturized absorbent paper. When the eggs are going to hatch, they turn grey. At this step, you have to deposit a fresh leaf of privet (ligustrum) in the box. After the hatching, caterpillars will go on or under the leaf and will start to eat. The temperature for this step and all the following must be between 20°C & 30°C.
L1 & L2 stages
At theses stages, small closed boxes are recommended. They maintain a good humidity for leaves and larvae. Nourrish them with fresh leaves when larvae have all eaten or if old leaves are dry (once or twice a day). If the caterpillars are fine, they eat well and you will see small dark round excrement.
L3 to L5 stages
During theses stages, caterpillars needs more space. It is better to transfer them in bigger boxes. You can now feed them with privet branch. If the box or the vivarium have enough space, you can place a pot with water and privet branch in it to keep fresh leaves longer. If you do that, close the pot with cotton to avoid caterpillars drowning. You can also feed them with lilac or cherry laurel but privet is better. At the end of L5, caterpillars become more translucid and lose weight. They are close to make their cocoons. You have to transfer them in an aviary.
Cocoon & chrysalis
At the end of L5, Caterpillars will search a safety spot to cocoon. It may be in leaves, branches or corners of the box or aviary and it's often in high point. Don't perturb them during the cocooning, it has a chance they stop to make their cocoon. After few days (2-3), you may manipulate the cocoon and you can enlarge the exit hole with scissors to help the butterfly's exit. You can pin cocoons on polystyren board or lay them on mesh board.
After 20 to 30 days, butterflies exit their cocoons and hang on durng the time to deploy their wings. Then, male will search female to mate. Bombyx eri are moth, so they are active during the night. They don't have digestive system, no need to feed them. They live around 10 days. Males have smaller abdomen and have bigger and more fluffy antennae. During the mating (it can last 24 hours), don't bother butterflies. Shortly after the mating, the female will lay eggs (generally in grapes). Bombyx eri isn't a specie with possible diapause, don't put eggs in the fridge.
Voilà, vous savez tout. Nous vous souhaitons un bon élevage et si vous avez remarques ou questions, n’hésitez pas a nous contacter. Nous sommes en train de mettre en place des ressources pédagogiques qui seront disponibles en ligne prochainement afin de faire découvrir la magie des papillons en classe.
From Albert, butterflies breeder since a good time
Un grand merci à Christine pour les photographies