Quebec monarchs migrate south in fall. The adults that overwinter in Mexico mate the following spring and the females then lay their eggs on milkweed. The monarchs make their way north, following the growth of their host plant and arriving in Quebec in June.
The females then lay their eggs and the caterpillars emerge three to twelve days later. They feed on milkweed leaves for two weeks.
Monarch caterpillars have black, yellow and white stripes and one pair of black filaments near their heads and another pair near the tip of the abdomen. After moulting five times, the caterpillar stops eating, attaches itself upside down under a leaf and turns into a green chrysalis.
The adult emerges from the chrysalis two weeks later. The butterfly is ready to fly off once its wings are dry and fully spread.
These monarchs reproduce in Quebec. The ones in the next generation (or the one after that, depending on the weather) do not reach sexual maturity here, but instead migrate to their overwintering sites in Mexico.
Their winter rest period lasts until March, when the males and females sexually mature and mate. Most of the males die, while most of the female head north. They lay their eggs on spring milkweed shoots and then they die. It takes several generations to reach Quebec, in June.