Ceratomia amyntor
(Geyer, 1835)
Elm Sphinx, Four-horned Sphinx
Ceratomia amyntor is a North hawkmoth with a wingspan of 8.2–11.5 cm. feed primarily on elm but also use birch, basswood, and cherry. The is notable for its four horns—additional to the horn typical of sphingids—giving rise to the "four-horned sphinx." are gray- with wavy markings and a small dot characteristic of the . The species has one in northern regions and up to five in the southern United States.



Pronunciation
How to pronounce Ceratomia amyntor: /ˌsɛrəˈtoʊmiə əˈmɪntɔr/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
Distinguished from similar Ceratomia by four horns on (vs. two in C. undulosa). recognized by gray- wavy with small dot; combination of broken body and plain gray with dark marginal band separates from . Larger size and more pronounced white head marking in some specimens may cause confusion with C. undulosa, but pattern details differ.
Images
Habitat
Deciduous forests and woodlands, suburban areas with trees present. Associated with elm, birch, basswood, and cherry stands.
Distribution
North America: Nova Scotia west to Alberta, western North Dakota, and Colorado; south to Florida, Gulf Coast, Georgia, Texas, Louisiana, and New Mexico.
Seasonality
Northern range: single , June–July. Southern range: two broods flying later in season; Louisiana records five broods March–October.
Diet
feed on leaves of Ulmus (elm), Betula (birch), Tilia (basswood), and Prunus (cherry). Has been observed on tomato and pepper plants.
Host Associations
- Ulmus - primary
- Betula - secondary
- Tilia - secondary
- Prunus - secondary
- Solanum lycopersicum - occasional tomato
- Capsicum - occasional pepper
Life Cycle
with five larval completed in approximately one month. descend tree and burrow underground to pupate; may overwinter as if late in season. Multiple in southern portion of range.
Behavior
exhibit "wandering" phase prior to , ceasing feeding and descending tree. , attracted to light.
Ecological Role
in deciduous forest ; larval can be substantial on trees. Serves as for and other .
Human Relevance
Occasional pest of vegetable (tomato, pepper) due to larval feeding. Otherwise not economically significant. Not threatened.
Similar Taxa
- Ceratomia undulosaSimilar size and coloration; distinguished by larval horn count (two horns vs. four in C. amyntor) and subtle pattern differences
- Ceratomia catalpaeShared and general ; C. catalpae specialized on Catalpa, lacks four horns as
- Smerinthus spp.Similar gray- hawkmoth appearance; distinguished by patterns on and lack of broken body
Sources and further reading
- BugGuide
- Wikipedia
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
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