The Luna Moth (Actias luna) is a large lime-green, Nearctic Saturniid moth in the subfamily Saturniinae.
Range
This moth is found in
North America from east of the
Great Plains in the
United States to northern
Mexico and from
Ontario eastward through central
Quebec to
Nova Scotia in
Canada.
Life cycle
Based on the
climate in which they live, the Luna moths produce differing numbers of
generations. In Canada and northern regions, they will produce only one generation per year. These reach
adulthood from early June to early July. In the north eastern
United States around
New Jersey or
New York, the moths produce two generations each year. The first of these appear in April and May, and the second group can be seen approximately nine to eleven weeks later. In the southern United States, there can be as many as three generations. These are spaced every eight to ten weeks beginning in March.
Egg
Female Luna moths lay 100-300 eggs, 4-6 eggs at a time, on the underside of leaves, and they
incubate for eight to thirteen days, depending on
climate.
Larva
Each
instar generally takes about five days to a week to complete. After hatching, the caterpillars tend to wander around before finally settling on eating the particular plant they are on. These caterpillars tend to be
gregarious for the first two to three instars, but separate and live independently after that. As with all Saturniids, these caterpillars go through five instars before
cocooning. At the end of each instar, a small amount of silk is placed on the major vein of a leaf and undergoes
apolysis. The caterpillar then undergoes
ecdysis, or moults from that position leaving the old
exoskeleton behind. Sometimes the shed exoskeleton is eaten. Each instar is green, though the first two instars do have some variation in which some caterpillars will have black underlying splotches on their
dorsal side. Variation after the second instar is still noticable, but slight. The dots that run along the dorsal side of the caterpillars vary from a light yellow to a dark magenta. The final instar grows to approximately nine
centimeters in length.
Pupa
The luna moth
pupates after spinning a
cocoon. The cocoon is thin and single layered. Shortly before pupation, the final, fifth instar caterpillar will engage in a "gut dump" where any excess water and fluids are expelled. The caterpillar will also have an underlying golden reddish brown color and become somewhat immobile. As pupa, this species is particularly active. When disturbed, the moth will wiggle loudly. Pupation takes approximately two weeks unless the individual is
diapausing. The mechanisms for diapause are generally a mixture of genetic triggers, duration of sunlight or direct light during the day, and temperature.
Adult
Adults eclose, or emerge from their
cocoons in the morning. Their wings are very small when they first emerge and they must enlarge them by pumping bodily fluids through them. During this time, their wings are very soft and fragile and they must climb somewhere safe to wait for their wings to harden before they can fly away. This process takes about 2 hours to complete. The Luna moth has a wingspan of between 8-11.5 cm with long, tapering hindwings, which have
eyespots on them in order to confuse potential predators. Although rarely seen due to their very brief (1 week) adult lives, Luna moths are considered common. As with all Saturniidae, the adults do not eat or have mouths. They emerge as adults solely to mate, and as such, only live approximately one week.
Images of life cycle
Image:Actias luna eggs sjh.JPG|Luna eggs
Image:Actias luna 1st instar sjh.JPG|1st instar caterpillars reared on American Sweetgum.
Image:Actias luna 2nd instar sjh.JPG|2nd instar caterpillars.
Image:Actias luna 3rd instar sjh.JPG|3rd instar caterpillar.
Image:Actias luna 4th instar ecdysis sjh.JPG|4th instar caterpillar emerging during ecdysis.
Image:Actias luna 4th instar sjh.JPG|4th instar caterpillar.
Image:Actias luna 5th instar 3 sjh.JPG|5th instar caterpillar.
Image:Actias luna 5th instar 4 sjh.JPG|5th instar caterpillar.
Image:Actias luna 5th instar 5 sjh.JPG|5th instar caterpillar defoliating American Sweetgum.
Image:Actias luna male pupa sjh.JPG|Male Pupa.
Image:Actias luna pupa sjh.JPG|Female Pupa.
Image:Actias luna pupa 2 sjh.JPG|Female Pupa and cocoon.
Image:Actias luna cocoons sjh.JPG|Luna cocoons.
Image:Actias luna male sjh.JPG|Adult male.
Image:Actias luna female sjh.JPG|Adult female.
Image:Luna moth01 800x600.jpg|Adult male.
Image:Actias luna mating sjh.JPG|Mating adults.
Host plants
The
caterpillars feeds on the following host plants:
Trivia
In
Michael Chabon's novel
The Amazing Adventures of Kavalier & Clay, the Luna Moth is a comic book character, drawn by
Joe Kavalier after his real-life girlfriend
Rosa Luxemburg Saks.
External links
Saturniidae