Lepidoptera eggs show a great variability in shape and color. The egg contains the embryo that hatches fully functional. The larval period is called post-embryonal development. Eggs are usually rounded, from 0,1cm to 0,3cm in diameter.
The duration of embryo development is strongly affected by temperature, every species has its own timing. Generally caterpillars hatch 1 or 2 weeks after egg laying. This means that eggs need to be shipped as soon as possible after deposition, to be safely received. For some species the egg is the stage that undergoes diapause (ex. A. yamamay).
Eggs are usually shipped into small plastic tubes. Once received, they need to be moved to a bigger container, allowing caterpillars to have enough space to hatch and move.
Standard 80mm plastic Petri dish (fig.A) are a very common tool to store the eggs and let the caterpillars hatch inside. Other kind of small plastic boxes can be used; it is recommended to perform holes or modify the boxes to allow aeration. Close the boxes with a fine mesh, tulle is widely used for this purpose (fig.B). Avoid the use of medium/big boxes because caterpillars will tend to move a lot and spread inside the box.
It is not recommended to put the leaves before the first caterpillars hatch. The presence of leaves inside a small enviroment can "poison" the air and reduce the hatching rate. This is especially true in case of toxic plants like Prunus laurocerasus or Nerium oleander.
To increase humidity (very useful with tropical species) place a small piece of wet paper inside the Petri dish or the box. Avoid cotton because small caterpillars could remain trapped into his filaments, this is especially dangerous with Sphingidae or Brahmaeidae caterpillars. Another strategy is to keep the eggs on wet paper inside a modified cage as shown in fig.B.
Pupa is the stage in which metamorphosis takes place. Depending on the species, pupae can be nude or protected inside a cocoon. The cocoon is produced by the caterpillar and is not part of the insect body. Some species produce a very loose or incomplete cocoon.
Lepidoptera pupae can weight up to 15-20g. They can be safely shipped in small or medium parcels. Once received, the treatment depends strictly on the species cycle and on the season. For pupae that are expected to hatch at RoomTemperature is sufficient to place them in the same cages used for adults. Pupae can be positioned in the bottom of the cage, better over some paper to keep humid or just to keep clean from meconium. Meconium is the earliest stool of an adult insect, it is easily cleaned with water but can be annoying. To stimulate pupae in hatching, they can be submerged in warm water for 1-5 minutes, than moved back to their place; this operation can be be performed once every two days or even more (very effective with Saturniidae). Tropical pupae, and all the pupae that are expected to hatch during the hot season, can be waken up with this method. This procedure helps in syncronizing adults emergence, which is a key factor to obtain pairings.
Example of Pupae from Saturniidae, Sphingidae, Brahmaeidae
Samia ricini male, genitals are positioned in the 5° segment if we start counting after the wings. In a female specimen genitals are positioned across the 4° and the 5° segment; they present a different "V-like" shape. Another feature that is recognizable in Saturniidae is the antennae sexual dimorphism, males usually present larger ones.