Ceratomia amyntor

Ceratomia amyntor
seer-a-TOHM-ee-uhmm uh-MIN-tor
The Elm Sphinx or Four-horned Sphinx
(Geyer, [1835]) Agrius amyntor

Ceratomia amyntor male courtesy of Vernon A. Brou, Jr.

This site has been created by Bill Oehlke at oehlkew@islandtelecom.com
Comments, suggestions and/or additional information are welcomed by Bill.


Family: Sphingidae, Latreille, 1802
Subfamily: Sphinginae, Latreille, [1802]
Tribe: Sphingini, Latreille, 1802
Genus: Ceratomia Harris, 1839 ...........
Species: amyntor (Geyer, [1835])


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The Elm Sphinx or Four-horned Sphinx, Ceratomia amyntor, (Wingspan: 3 1/4 - 4 1/2 inches (8.2 - 11.5 cm)), flies from Nova Scotia west to Saskatchewan and western North Dakota and Colorado; south to central Florida, the Gulf Coast, Texas, and New Mexico and into Mexico. Jim Tuttle now (2009) reports there have been larval and adult sightings in southeastern Arizona.

I have not seen this species on Prince Edward Island, Canada, but my father has taken females at lights and reared larvae in Pottersville, New Jersey.

The specimen type locality is Pennsylvania.

Ceratomia amyntor Patrick Coin, used with permission,
Durham County, North Carolina, August 1, 2003

The upperside of the forewing is brown with dark brown and white markings including a white costal area near the wing base, dark streaks along the veins, and a white spot in the cell. The upperside of the hindwing is light brown and has a dark brown band along the outer margin.

Ceratomia amyntor on elm, June 9, 2005, Peterborough, Ontario, courtesy of Tim Dyson.

Ceratomia amyntor undersides, Peterborough, Ontario, courtesy of Tim Dyson.

Visit Ceratomia amyntor, MV light on small building on County Hwy R18, Boone County, Iowa, June 23, 2009, Thomas Jantscher

Visit Ceratomia amyntor, Ogemaw County, Michigan, July 6, 2012, Cindy Mead


Ceratomia amyntor adults fly as a single brood in a wide variety of forested and open habitats in the northern portions of their range from June-July. There are two broods further south, and Vernon A. Brou confirms five broods in Louisiana from March-October.

Ceratomia amyntor, Peterborough, Ontario, June 8-9, 2005, courtesy of Tim Dyson.


Pupae probably wiggle to surface from subterranean chambers just prior to eclosion.


Females call in the males with a pheromone released from a gland at the tip of the abdomen. Adults probably do not feed.

Ceratomia amyntor eggs in brown bag, July 2, 2005, courtesy of Tim Dyson.


Females will readily oviposit translucent, lime green eggs in brown paper sandwich bags.

Tim Dyson has provided this image of a first instar larva on elm, Peterborough, Ontario, July 5, 2005.

Sphingidae rearing is much easier now that we have learned a natural pupation medium is not necessary. At maturity, larvae will be placed in dark buckets lined with several layers of paper towels. After a bit of wandering, larvae will crawl under towelling and pupate.

This first instar larva will probably feed for approximately four-five weeks.

Larvae feed on Elm (Ulmus), birch (Betula), basswood (Tilia), black locust (Robinia pseudoacacia) and cherry (Prunus).

There are chocolate-brown to orangey-brown, sometimes with a pinkish tint, and green forms of the larvae. The common names are derived from foodplants (Elm Sphinx) and the structure (Four-horned Sphinx) of the larva.

Green form to right is courtesy of Tim Dyson.

Tim Dyson reared a number of these during the warm 2005 Ontario summer. Larvae moved through five instars in approximately one month.

"Pink" form to right is courtesy of Tim Dyson. There is often a mix of brown and green tones on the larvae.

Dark form courtesy of Tim Dyson.

Visit Ceratomia amyntor larva (green form), Washington County, Rhode Island, August 27, 2009, Ryan Saint Laurent.

Visit Ceratomia amyntor larva (green form), Norton, New Brunswick, Canada, September 7, 2009, Gordon Snyder.

Visit Ceratomia amyntor, Saskatoon, Saskatchewan, September 5, 2011, Betty Wotherspoon.

Fully-grown caterpillars excavate subterranean chambers and pupate in and overwinter in those underground burrows.

Ceratomia amyntor pupa, courtesy of Tim Dyson.

Many thanks to Ian Miller who has provided sighting data for many species, including C. amyntor in Eau Claire County, Wisconsin.

Ian writes, "Four-horned sphinx larva bit the webbing of my finger while I tried to move him to another birch cutting and drew blood. He has some big old jaws on him and very powerful. Won't be picking him up for a while."

The pronunciation of scientific names is troublesome for many. The "suggestion" at the top of the page is merely a suggestion. It is based on commonly accepted English pronunciation of Greek names and/or some fairly well accepted "rules" for latinized scientific names.

The suggested pronunciations, on this page and on other pages, are primarily put forward to assist those who hear with internal ears as they read.

There are many collectors from different countries whose intonations and accents would be different.

I do not know the origin of the genus choice Ceratomia, but the first species assigned to this genus is amyntor. Ceratomia may be a combination of cera (gold) and tomia (cutting). Speculation suggests the dark cuttings (streaks) into the golden brown area of the forewing or the golden checkered fringe.

The species name "amyntor" is from Greek mythology/legend. Amyntor is the king of the Dolopes. He is killed by Heracles when the king denies Heracles access to his realm.

There would appear to be no descriptive significance for this name choice.

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