In southern Ontario, June is the month for Giant Silkmoths to emerge! Since late last summer, all through the winter and most of the spring, they are in the pupa stage of development, wrapped in silken cocoons. Finally, in late spring, the adult moths push their way out of the cocoon, climb up a bit and pump fluids into their wings. They are beautiful and very big – the Cecropia is the largest moth north of Mexico! Polyphemus, Luna and Promethea are other Giant Silkmoths in our area (southern Ontario).
At night, a newly-emerged female emits a pheromone that attracts males from up to a kilometre away! Males have wide, feathery antennae to detect the female’s pheromones, while females have much narrower antennae. After mating, the female lays up to a few hundred eggs on tree leaves that the caterpillars will feed on.
The newly-hatched caterpillars are insatiable eaters and grow quickly; if a human baby grew as fast it would weigh as much as an elephant after only a couple of months!
Finally, in late summer, the caterpillar spins a cocoon to protect it through the cold winter months, and it changes into a pupa.
Raising these amazing moths has been a hobby of mine for many years. I give cocoons to school classes so they can observe the amazing life cycle of these moths. If you live within an hour or so of Guelph, Ontario, contact me to get a cocoon if you would like to observe this.
Finding these moths can be a challenge! They only live for a week or two as adults, and they fly at night. People often mistake them for bats. The caterpillars are camouflaged and are often high in trees. I have sometimes found Cecropia cocoons on tree branches in winter.