endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Currently central New Jersey across southern Pennsylvania west through most or all of Indiana, much of Illinois half of Missouri south the extreme eastern Texas, the entire Gulf coast and central Florida. Until the 1950s also much of New York, most of southern New England, and most of Pennsylvania.
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: Still very widespread and in places common south of latitude 39 degrees, extirpated or nearly so north and east of South Jersey.
10,000 to >1,000,000 individuals
Molecular Biology and Genetics
Barcode data: Citheronia regalis
There are 6 barcode sequences available from BOLD and GenBank. Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Citheronia regalis
Public Records: 6
Specimens with Barcodes: 15
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Reasons: Still doing well in most of its range, but extirpated or declining in a significant part, with expanding threat. See threats and trend fields. Furhter decline is likely, range-wide collapse seems very unlikely.
Intrinsic Vulnerability: Moderately vulnerable
Global Short Term Trend: Relatively stable (=10% change)
Comments: There have been reports of decline in Ohio but little information--decline in northern parts of range does seem likely based on what happened in the Northeast. The species definitely recovered some in New Jersey and spread north to the central counties in the 1990s. Stable in most of range for now but possibly declining in small part.
Global Long Term Trend: Increase of 10-25% to decline of 30%
Comments: Extirpated in several states, in most cases coinciding perfectly in time and space with past DDT spraying against gypsy moth. However there seems to be no doubt that the out of control gypsy moth biocontrol Compsilura concinnata was much more important and prevented recovery. This fly has spread over a much larger area since put does not always greatly reduce Saturniidae. If the regal moth has really collapsed in central Ohio, Compsilura would be athe almost certain cause. Stable in large area of Southeast at present and recovering in parts of New Jersey where it was very rare to (mostly) absent in the 1960s-1980s, but still overall sporadic and mostly uncommon to rare in that state. Probably declining somewhat overall with the spread of Compsilura but range-wide collapse is not expected..
Degree of Threat: Medium
Comments: Threats from biocides have probably abated somewhat but some impact is likely as Compsilura progresses westward and southward. Some Lepidopterists believe this and related species are vulnerable to artificial lighting, but there is no evidence and the species has recovered in some fairly developed parts of New Jersey.
Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed
Comments: Almost any preserved or well managed forest from Cumberland Co., NJ or MD, n. VA southward is still likely to have this if.
Needs: Secure protection of extensive areas from Dimilin use. Bt will not affect this species as current formulations do not persist long enough.
|This article does not cite any references or sources. (June 2013)|
The regal moth (Citheronia regalis), also called the royal walnut moth, is a North American moth in the saturniidae family. The caterpillars are called hickory horned devils. The adult (Imago) has a wingspan of 3.75-6.1 in (9.5-15.5 cm).
Yellowish eggs, oval and 2 mm in diameter, are laid either singly or in groups of up to four on the upper surface of the host plant leaves, favoring nut trees such as Juglans and Carya (walnuts and hickories). There are regional preferences, with the utilization of sweet gum and persimmon in the south, and sumacs where the others are not available. Larvae are solitary in later stages and rarely occur in numbers large enough to cause defoliation, however an individual larva can strip several branches of their leaves during the ravenous 5th instar.
The general list of recorded hosts contains hickories (Carya glabra, Carya illinoensis, Carya ovata), Buttonbush, Filbert, Bush honeysuckle, Persimmon, Ash, Cotton, Butternut, Black walnut, English walnut, Sweetgum and Privet among others.
When the eggs hatch 7–10 days later, small yellow larvae that darken rapidly emerge. The caterpillars are solitary nighttime feeders in early stages, when they curl up in a "j" shaped pattern during the day and resemble two-toned bird droppings.
As the caterpillars age, they feed during the day. They molt 5 times. Each instar is different, but on their sixth and final instar they become a bright green color, with huge, black-tipped red horns, earning them their common name "hickory horned devils". They feed heavily on their host plant and can grow up to 15 centimetres (5.9 in) long. Their scary appearance is purely a ruse; the spines, though prickly, do not sting, and the larva is harmless and actually one of the more easily handled of the saturniidae.
Just before pupation, the larva expels its gut and changes color from Frankenstein-green to a more fetching turquoise, the skin of the fully fed creature stretched shiny and tight. They then crawl down the host plant, where they burrow into the dirt and pupate in a well formed chamber at a depth of five to six inches. The pupae are dark brown/black in color, and have a relatively short cremaster. Some pupae overwinter for 2 seasons, perhaps as an adaption to variable and adverse conditions such as fires and flooding, or to maintain genetic diversity across generations.
When the moths eclose, they have to pump their wings with fluid (hemolymph) to extend them. The females emit pheromones, which the male can detect through its large, plumose antennae. Males can fly for miles in order to reach a female. After the moths mate, the female spends the majority of the remainder of her life laying eggs, while the male may mate several more times. Adults of this family of moths have vestigal mouths, meaning their mouthparts have been reduced. Because of this, they do not eat and only live for about a week as adults.
There is a single generation of Citheronia regalis throughout its range, but in the deep south, moths have been recorded throughout the longer growing season. Typically, Citheronia regalis is a midsummer moth, on the wing from late June through August. There is a distinct bell curve to the emergence, with peak-weeks coinciding with the first spell of the humid summer weather which may synchronize emergences.
Citheronia regalis is considered a common species in the Deep South, becoming rarer and more sporadic northward. Historically recorded throughout New England, the species suffered a decline in the Atlantic Northeast during the mid-20th century. This may be related to DDT spraying, the use of Bt to combat gypsy moth infestation, and the deployment of the non-native Compsilura fly as a bio-control agent backfiring in producing declines of saturniid species.
Excluding sparse contemporary records from New York, Citheronia regalis achieves range stability in the mid Atlantic states and southern Appalachia, beginning from southern New Jersey west throughout the Ohio Valley, the edge of the Great Plains states and south to East Texas.