Editing Luna moth (section)

== Life cycle ==
[[File:Actias Luna Fieldbookofinsec00lutz 0195.jpg|alt=Drawing of lifecycle|left|thumb|upright|Illustration by [[Edna Libby Beutenmüller|Edna Libby Beutenmuller]] from ''Field Book of Insects'' (1918)]]
Based on the [[climate]] in which they live, Luna moths produce different numbers of [[generation]]s per year. In Canada and northern regions of the United States, they are [[voltinism|univoltine]], meaning one generation per year. Life stages are approximately 10 days as eggs, 6–7 weeks as larvae, 2–3 weeks as pupae, finishing with one week as winged adults appearing in late May or early June. In the mid-Atlantic states, the species is bivoltine, characterized by two generations per year. In contrast, farther south, they are trivoltine, producing three generations within the same time frame. In the central states, the first generation appears in April, the second in July. Even farther south, the first generation appears as early as March, with the second and third spaced eight to ten weeks later.<ref name=Tuskes1996/>

=== Eggs ===

Females lay 200–400 eggs, singly or in small groups, on the underside of leaves of the tree species preferred by the larvae. Egg laying starts the evening after mating is completed and goes on for several days. Eggs hatch in about a week.<ref name=Tuskes1996/><ref name=UnivFL/>

=== Larvae ===

Each [[instar]] &ndash; the period between molts &ndash; generally takes about 4–10 days. There are five instars before [[Cocoon (silk)|cocooning]]. At the end of each instar, a small amount of silk is placed on the major vein of a leaf and the larva undergoes [[apolysis]], then [[ecdysis]] (molting), leaving the old [[exoskeleton]] behind. Sometimes the shed exoskeleton is eaten. Newly hatched, this caterpillar constantly munches on the leaves of walnut, hickory, sweetgum, and paper birch trees. Each instar is green, though the first two instars do have some variation in which some larvae will have black underlying splotches on their [[Dorsum (biology)|dorsal]] side. The final instar grows to approximately {{convert|70|to|90|mm|abbr=on}} in length. All five instar stages possess green spines on the dorsal surface. These spines do not sting, but can still cause irritation upon contact.<ref>{{Cite web |last=Ahmed |first=Aleem |date=2024-05-21 |title=Green Caterpillars: Discover Types, Identification, and Control |url=https://gardencomposer.com/green-caterpillars/ |access-date=2024-08-08 |website=AI Garden Composer}}</ref> This is a tree-dwelling species. Larvae stay on the same tree where they hatched until it is time to descend to the ground to make a cocoon. When females emerge from cocoons, they fly to preferred tree species, emit pheromones, and wait there for males to find them.<ref name=Tuskes1996/><ref name=UnivFL/> Although some larvae in the family [[Saturniidae]] are known to be poisonous, those of ''A. luna'' are not. The spines, or setae, located on the thoracic and abdominal segments have no chemical component to them.<ref>{{cite web |last=Hall |first=D. W. |date=October 2019 |url=https://entnemdept.ufl.edu/creatures/misc/moths/luna_moth.htm |title=Common name: luna moth: scientific name: ''Actias'' (=''Tropaea'') ''luna'' (Linnaeus) (Insecta: Lepidoptera: Saturniidae: Saturniinae) |publisher=Featured Creatures, University of Florida |access-date=December 6, 2021}}</ref>

=== Pupae ===

The Luna moth [[pupa]]tes after spinning a silk cocoon, which is thin and single layered. Shortly before pupation, the final, fifth-instar caterpillar will engage in a "gut dump" where any excess water and intestinal contents are expelled. As pupae, this species is more physically active than most moths. When disturbed, the moths will wiggle within their pupal cases, producing a noise. Pupation takes approximately two weeks unless the individual is in [[diapause]] over winter, in which case the pupal stage takes about nine months. The mechanisms triggering diapause are generally a mixture of genetic triggers, duration of sunlight and temperature. The pupae have chitinous spurs near the base of the forewings. By vigorously moving about within the cocoon, these spurs tear a circular opening from which the imago emerges, the silk of the cocoon having also been weakened by the secretion of [[cocoonase]], a protein-digesting enzyme.<ref name=Tuskes1996/><ref>{{cite web |url=http://entnemdept.ufl.edu/Creatures/MISC/MOTHS/polyphemus_moth.htm |title=Polyphemus moth |last=Hall |first=DW |website=Featured Creatures, Entomology & Nematology Department, University of Florida |access-date=8 August 2018}}</ref>

=== Imago (winged) ===

Pupae transition to winged state after receiving external signals in the form of temperature change. When the adult Luna moths emerge from their pupae, their abdomens are swollen and their wings are small, soft and wet. The first few hours of adult life will be spent pumping [[hemolymph]] (invertebrates' equivalent to blood) from the abdomen into the wings. The moths must wait for the wings to dry and harden before being able to fly. This process can take 2–3&nbsp;hours to complete. Luna moths are not rare, but are rarely seen due to their very brief (7–10 day) adult lives and [[nocturnal]] flying time. As with all giant silk moths, the adults only have vestigial mouthparts and no digestive system and therefore do not eat in their adult form. Instead, they rely on energy stored during their caterpillar stage. In regions where there are two or three generations per year, the second and third may have wing coloration that is more of a yellow-green compared to the first generation of the year.<ref name=Tuskes1996/>

=== Mating ===

Giant silk moths have in common a mating process wherein the females, at night, release volatile sex [[pheromone]]s, which the males, flying, detect via their large [[Antenna (biology)|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.<ref name=Tuskes1996 /> Researchers extracted three chemical compounds from the pheromone gland of unmated Luna moth females and identified one major and two minor aldehyde compounds designated ''E''6,''Z''11-18:Ald, ''E''6-18:Ald and ''Z''11-18:Ald. The same compounds were also synthesized. Field experiments with both unmated females and the synthesized compounds confirmed that E6, Z11-18:Ald was the major sex pheromone, attraction augmented by the addition of E6-18:Ald but not by Z11-18:Ald. The authors mentioned that no other moth species were attracted to either the unmated females or the synthesized products, confirming that the pheromone is species-specific, at least for the sites and dates where it was tested.<ref>{{cite journal |vauthors=Millar JG, Haynes KF, Dossey AT, McElfresh JS, Allison JD |title=Sex attractant pheromone of the Luna moth, ''Actias luna'' (Linnaeus) |journal=[[Journal of Chemical Ecology]] |volume=42 |issue=9 |pages=869–876 |date=2016 |pmid=27544534 |doi=10.1007/s10886-016-0751-6 |bibcode=2016JCEco..42..869M |s2cid=44327978 }}</ref>

=== Gallery of life cycle ===
<gallery>
File:Actias luna eggs sjh.JPG|Eggs from female raised in captivity, laid on coarse paper
File:Actias luna 1st instar hatching sjh.jpg|Hatching larva
File:Actias luna 4th instar sjh.JPG|4th-instar larva. Spots can also be yellow or magenta.
File:Actias luna spinning sjh.JPG|5th-instar larva starting to create a cocoon (note silk strands to leaves)
File:Actias luna male pupa sjh.JPG|Pupa, removed from cocoon. Eyes visible at head end (left)
File:Actias luna emergence male 7 sjh.JPG|Wings drying and enlarging after emergence from pupa
File:Actias luna mating sjh.JPG|Mating imagoes (winged adults). Male, with larger antennae, on left
</gallery>

=== Close-up images ===
<gallery>
File:Luna Moth, closeup of antennae.jpg|Antennae (male)
File:Actias luna eyespot sjh.JPG|Eye-spot on hindwing
File:Luna moth eye spot.jpg|Eye-spot on forewing
File:Luna moth scales.jpg|Extreme close-up of scales in eye-spot
</gallery>