Download NYNHP Conservation Guide for Imperial Moth

Imperial Moth
Eacles imperialis (Imperial Moth)
Scientific Name
Eacles imperialis imperialis
(Drury, 1773)
Family Name
Saturniidae
Giant Silkworm and Royal
Moths
Did you know?
There are two Imperial Moth subspecies: Eacles
imperialis pini and Eacles imperialis imperialis. The
pini subspecies feeds exclusively on pines, while
the imperialis subspecies feeds on several different
tree species.
Photo credits: Jim Vargo
Summary
Protection Not listed in New York State, not listed federally.
This level of state protection means: The species is not listed or protected by New York
State.
Rarity G5T5, SU
A global rarity rank of G5T5 means: Secure globally - Both the species as a whole and the
subspecies/variety are common in the world; widespread and abundant (but may be rare in
some parts of its range).
A state rarity rank of SU means: Unrankable.
Conservation Status in New York
Additional surveys are needed before assigning a state rank. As of 2012, there are five
extant occurrences in New York State. Occurrences are known to be in the northern
portion of the state and on Long Island, but not in between.
Short-term Trends
The short-term trends are unknown.
NYNHP Conservation Guide - Imperial Moth (Eacles imperialis imperialis)
Long-term Trends
Populations declined in the mid-twentieth century most likely because of increased use of
pesticides, metal halide bulbs, and the introduction of parasitoids, such as Compsilura
concinnata (tachinid fly) that was introduced in 1906 (Goldstein 2010; Hedbor 2006,
Schweitzer et al. 2006).
Conservation and Management
Threats
This species is believed to be severely impacted by pesticides and parasitoids, such as
Compsilura concinnata tachinid fly (Goldstein 2010; Hedbor 2006).
This species is attracted to artificial lighting. Artificial lighting can: increase predation risk,
disrupt behaviors such as feeding, flight, and reproduction, and interfere with dispersal
between habitat patches. In addition, many individuals die near the light source. It is not
known if the impact of artificial lighting is severe, but the impact is likely greater for small,
isolated populations (Schweitzer et al. 2011).
Conservation Strategies and Management Practices
Insecticide use should be avoided when possible if rare species are present. When
insecticide use cannot be avoided, careful planning along with consistent rare species
monitoring, can result in successful eradication of the target species without eliminating
rare species. A biocontrol alternative is Bacillus thuringiensis (Btk) for some target species,
such as gypsy moths. However, sensitivity to Btk varies among native species and this
option should be fully researched for treatment timing and regimes and weighed with other
options to have the least impact on native lepidopteran populations. Gypsy moth
management should be well planned to minimize impacts to rare species when they are
present. However, gypsy moths can also cause severe forest defoliation. This can lead to
the starvation of larvae. The greatest impact is when defoliation occurs in consecutive
years. Often, summer-feeding lepidopterans can be the most affected because they often
need to feed on mature oak leaves. When they are forced to only eat the regrowth (young
leaves), they tend to be undersized compared to larvae that are feeding on mature leaves
(Schwietzer et al. 2011). There are two other gypsy moth biocontrols that are currently
unavailable, but appear to be very effective at eliminating gypsy moths with little effect on
non-target species: Gypchek (a viral preparation) and Entomophaga maimaiga (a fungus).
Minimizing lighting to maintain dark sky conditions would be beneficial. When lighting is
necessary, it's best to use lights that emit red or yellow light because insects are generally
not attracted to those colors. However, many sodium lights, which emit yellow light, are so
bright that they do attract some insects. The best lighting appears to be low pressure
sodium lights which have little effect on flying insects (Schweitzer et al. 2011).
Research Needs
Additional research is needed to gain a better understanding of this species' life history and
habitat needs.
NYNHP Conservation Guide - Imperial Moth (Eacles imperialis imperialis)
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Habitat
In the northern portion of its range, this species has been found in calcareous pavement barrens.
On Long Island, the precise habitat has not been verified, except that captures were made between
maritime grassland and maritime dunes or between a sea level fen and maritime heathland. The
following trees have been recorded as foodplants: basswood, birches, cedar, elms, maples, oaks,
pines, and walnut.
Associated Ecological Communities
Calcareous Pavement Barrens
A savanna community that occurs on nearly level outcrops of calcareous bedrock
(limestone or dolomite). The community consists of a mosaic of shrub-savanna,
grass-savanna, and rock outcrop vegetation.
Other Probable Associated Communities
Maritime dunes
Maritime grassland
Maritime heathland
Identification Comments
Identifying Characteristics
Imperial moth is a large moth with a wingspan between 8 and 17.4 cm. It has yellow wings
with spotting and shading variations of pink, orange, or purplish brown. Males tend to be
more heavily marked than females, especially to the south (Covell 1984). A full grown larva
is 75 to 100 mm long. There are two color variations: green and brown. The body has long
whitish hairs. The second and third thoracic segments each have two stubby, rough
"horns" and a rows of smaller spines along the rest of the body. There are large black and
yellow plates on the last abdominal segment. Oval, yellow to cream spiracles are found on
the sides. The brown variation has tan to reddish brown horns and spines. The pupa are
large, spinose, and very active when handled (Tuskes et al. 1996). Large, yellow eggs are
laid on either side of the foodplant singly or in small groups (Hyche 2000, Tuskes et al.
1996).
Best Life Stage for Identifying This Species
Adult.
Behavior
Adult males are very strong fliers. This species pupates underground in loose soil. It is very
active when handled (Tuskes et al. 1996).
NYNHP Conservation Guide - Imperial Moth (Eacles imperialis imperialis)
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Diet
Larval foodplants are many tree species including: basswood, birches, cedar, elms,
maples, oaks, pines, and walnut.
The Best Time to See
Imperial moths can be found May through July in the northern portion of its range. There is
one brood each year (Covell 1984).
Present
Active
Jan Feb Mar Apr May Jun Jul
Aug Sep Oct Nov Dec
The time of year you would expect to find Imperial Moth in New York.
Similar Species
Imperial Moth(Eacles imperialis pini): The pini subspecies is smaller with more pink and
has a strong postmedial line on the hindwing.
Taxonomy
Kingdom
Animalia
Phylum
Mandibulates (Mandibulata)
Class
Insects (Insecta)
Order
Butterflies, Skippers, and Moths (Lepidoptera)
Family
Saturniidae (Giant Silkworm and Royal Moths)
Additional Resources
Links
http://bugguide.net/node/view/4757
NatureServe Explorer
http://natureserve.org/explorer/servlet/NatureServe?searchName=EACLES+IMPERIALIS+I
MPERIALIS
Google Images
http://images.google.com/images?q=EACLES+IMPERIALIS+IMPERIALIS
NYNHP Conservation Guide - Imperial Moth (Eacles imperialis imperialis)
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References
Beadle, D. and S. Leckie. Peterson field guide to moths of Northeastern North America. Houghton
Mifflin Harcourt: New York, NY.
Covell, Charles V. 1984. A field guide to the moths of eastern North America. Houghton Mifflin
Company, Boston.
Goldstein, Paul Z. 2010. Life history of the Imperial Moth Eacles imperialis (Drury) (Saturniidae:
Ceratocampinae) in New England, U.S.A.: distribution, decline, and nutritional ecology of the
relictual islandic population. Journal of Research o the Lepid
Hedbor, James. 2006. Eacles imperialis (Imperial Moth) gaining ground in Vermont? Vermont
Entomological Society News 52 (summer 2006): 4.
Hyche, L.L. 2000. Imperial Moth Eacles imperialis (Drury) (Saturnidae). Department of Entomology
and Plant Pathology, Auburn University.
http://www.ag.auburn.edu/enpl/bulletins/imperialmoth/imperialmoth.htm
Keys, Jr.,J.; Carpenter, C.; Hooks, S.; Koenig, F.; McNab, W.H.; Russell, W.;Smith, M.L. 1995.
Ecological units of the eastern United States - first approximation (cd-rom), Atlanta, GA: U.S.
Department of Agriculture, Forest Service. GIS coverage in ARCINFO format, selected imagery,
and map unit tables.
NatureServe. 2005. NatureServe Central Databases. Arlington, Virginia. USA
NatureServe. 2011. NatureServe Explorer: An online encyclopedia of life [web application]. Version
7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed:
April 17, 2012 ).
Schweitzer, D.F., M.C. Minno, and D.L. Wagner. 2011. Rare, Declining, and Poorly Known
Butterflies and Moths (Lepidoptera) of Forests and Woodlands in the Eastern United States.
USFS Technology Transter Bulletin, FHTET-2009-02.
Tuskes, P. M., J. P. Tuttle, and M. M. Collins. 1996. The Wild Silk Moths of North America: A Natural
History of the Saturniidae of the United States and Canada. Cornell University Press, Ithaca,
New York. 250 pp.
New York Natural Heritage Program
This project is made possible with funding from:
625 Broadway, 5th Floor,
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Albany, NY 12233-4757
Estuary Program
Phone: (518) 402-8935
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[email protected]
- New York State Office of Parks, Recreation and Historic Preservation
Information for this guide was last updated on Oct 29, 2015
This guide was authored by
NYNHP Conservation Guide - Imperial Moth (Eacles imperialis imperialis)
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