Papilio machaon high mortality with larvae

Hello,
anyone knows techniques for mass-reraring of Papilio machaon?
In last 2 years I experienced continuously losses whatever I rear them newly hatched larvae in small groups or larger groups. Maybe they don't go well on cut stems of foodplants (Foeniculum vulgare, Petroselinum sp., Ferula communis) but I had losses also with larvae left on the same potted foodplant were the parents laid eggs (Ruta graveolens).