Adult dogbane beetles lay their eggs on the underside of dogbane leaves. Leaf beetle larvae typically go through four to five growth stages or instars. The pupal stage of the life cycle follows the last larval instar. You can easily investigate the leaf beetle's cycle indoors. You will need some supplies.
Plastic shoeboxes are inexpensive and work well as beetle rearing cages.
Next, you will need several aqua-pics, small plastic cylinders with rubber lids, available from most florist shops. Aqua-pics will keep the food plants you collect fresh while beetles feed on them. Once the beetle housing has been completed, collect your beetles. Collecting and Rearing Leaf beetles are found almost anywhere there is vegetation. A close search of garden, field, or forest will usually turn up several species.