To hang a monarch pupa to hatch in a net cage please see the instructions below.
Tie a piece of thread around the cremaster and with a needle or pin carefully tease away the silk that is holding the pupa to the surface. Leave the silk attached so the thread does not slip off (see figure below). If the pupa has fallen and there is very little silk remaining, add a drop of glue to the thread where it surrounds the cremaster. The loose ends of thread can then be tied through a hole in the container cover or through a space in the netting. Clothes pins can also be used to hold the loose end of the thread to a ring stand or other similar object. It is alright to handle the pupa carefully and even set it on a table for a minute. Once the thread is attached to the pupae place use tape and and attach it the roof of the net cage for hatching. The pupa must be hung to allow the monarch to fully and safely emerge.
The adult will emerge in in a few days. When it is ready to emerge, the adult wings will be visible through the pupa covering. Once the monarch adult emerges please release them into the wild in 1-3 days. If you release them, wait for the wings to dry. Monarchs that emerge in the morning can be released at the end of the day, or kept until the following day without needing to be fed. Those emerging in the afternoon should be released the next day. It is best if they are released on a warm sunny day, near flowers if possible. If it is colder than 14° C, they often cannot fly as the butterflies require warmer weather for release.