Luna Moth Life Cycle

Everyone loves Luna Moths. With their beautiful bright green wings and super short lifespans, they're somewhat of a mystery. Luna moths belong to the family of giant silkworm moths called Saturniidae. These magnificent creatures can live less than 10 days as a winged adult after taking up to 12 months for metamorphosis. 

Similar to other members of the giant silkworm moth family, Luna moths undergo 4 stages of metamorphosis:  Egg, Larva, Pupa, & Moth.

It all starts with an egg that hatches after 10 to 12 days-females lay between 200 & 400 eggs, singly or in small groups, on the underside of leaves of tree species preferred by the larvae. Egg laying starts the evening after mating is completed and goes on for several days. Eggs hatch after about a week

The larva that emerge from eggs go through 5 instars before they're ready to pupate-an instar is the phase between two periods of molting in the development of an insect larva or other invertebrate animal. The larval stage can be considered the most important part of the Luna moth’s entire life. The adult Luna moth does not have a mouth and so it does not eat anything during the 10 days that it lives. The energy needed during the adult stage is stored in the form of fat during the larval stage. Which is why the larvae keep on eating without taking a break. All they do is to eat and poop. Depending upon the availability of food and climate, each instar may take anywhere between 4 to 10 days. After each instar a small amount of silk is placed on a major vein of the leaf. With each molt, they leave their old exoskeleton behind which they may consume. Larvae stay on the same tree where they hatched until it is time to descend to the ground to make a cocoon, or pupate. 

The pupal phase begins after the 5th instar, in which the larvae begins to spin a cocoon made of thin single-stranded silk. This is the most active stage of a Luna moth in its entire life cycle. If you've ever seen a Luna moth cocoon you may have felt movement inside the cocoon. The days spent in the pupal phase depend on environmental conditions. Under normal weather conditions, the pupal phase can take around 2 weeks. During winter seasons the pupa may enter a state of dormancy and can take up to 9 months for it to come out of the cocoon as an adult Luna moth. When it's time for the pupae to come out, it releases a protein-digesting enzyme that weakens the silk threads. Apart from this, there are chitinous spurs in their forewings used to make holes in the cocoon through which the adult Luna moth emerges.

When the winged Luna moth emerges from the cocoon its abdomen will be swollen. This is due to the accumulation of hemolymph (insect blood) in its belly. During the first few hours, this hemolymph is pumped to different parts of the body, including the wings. At this stage, the Luna moth needs to wait 2 to 3 hours for its wings to dry and harden before it can fly. Once the wings are dry, the moth flies off in search of a mate, as the sole purpose of an adult Luna moth is to make more Luna moths. Since Lunas don't have mouths, they derive energy from the stored fats from larval stage. This stored fat is only enough to survive for a maximum of 10 days, during which most of their energy is dispensed mating. 

And the cycle repeats...