Luna Moth

Jul 05, 2019

Actias luna: a conspicuous nocturnal moth of Hudsonville.

Family: Saturniidae
Subfamily: Saturniinae, a group commonly called Giant Silk Moths
Identification: This was the first North American saturniid to be reported in the insect literature. Hind wings have long curving tails. Wings are pale green, each with a transparent eyespot. Outer margins are pink in the southern spring brood, yellow in the southern summer brood and in northern populations.
Wing Span: 2 15/16 – 4 1/8 inches (7.5 – 10.5 cm).
Life cycle: Adults are very strong fliers and are attracted to lights. Giant silk moths have in common a mating process wherein the females, at night, release volatile sex pheromones, which the males, flying, detect via their large antennae. Males can detect these molecules at a distance of several miles, and then fly in the direction the wind is coming from until reaching the female. Luna moth females mate with the first males to find them, a process that typically starts after midnight and takes several hours. Females lay eggs in small groups or singly on both surfaces of host plant leaves. Life stages are approximately two weeks as eggs, 6–7 weeks as larvae, nine months as pupae, finishing with one week as winged adults appearing in late May or early June. Leaves and silk are used to spin papery brown cocoons in litter under the host plant. Male and female Luna moths can be distinguished by their antennae. A Male’s is larger and bushier.  
below a male southern spring brood.

Flight: One brood from May-July in the north, two to three broods from March-September in the south.
Caterpillar Hosts: A variety of trees including white birch (Betula papyrifera), persimmon (Diospyros virginiana), sweet gum (Liquidambar styraciflua), hickories (Carya), walnuts (Juglans), and sumacs (Rhus).
Adult Food: Adults do not feed, no mouth parts.

I find the adult alive occasionally, but I frequently find the remnants of the adult, usually eaten by ants, which leave the wings. The picture on the left shows the right hind wing with teeth marks.

The adult does not show any mouth parts.

Holley collected cocoons in fall and kept them alive and developing over winter into Spring. She offered me a container in which the chrysalis of a few Luna Moths were budging, ready to reveal their adult phase. They emerge from the pupae with the wings small, crumpled and held close to the body. Over a period of several hours the wings will enlarge to full size. I took a short video as I release the first one, which hatched over night.

The Luna moth appeared on a first class United States postage stamp issued in June 1987.