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Genus Mesothea

Day Emerald - Mesothea incertata Day Emerald Moth - Mesothea incertata - female Butterfly on serpentine tundra, Newfoundland - Mesothea incertata Mesothea incertata - male Moth, Mesothea incertata #7087 - Mesothea incertata green moth - Mesothea incertata green moth - Mesothea incertata Emerald Moth - possible Mesothea incertata - Mesothea incertata
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Geometroidea (Geometrid and Swallowtail Moths)
Family Geometridae (Geometrid Moths)
Subfamily Geometrinae (Emeralds)
Tribe Hemitheini
Genus Mesothea
1 species in North America (
wingspan to 20 mm
Adult: wings uniformly yellowish-green to dusky green; PM line slightly wavy, indistinct (sometimes absent), often the only visible marking

Larva: green with brown dorsal stripe; body slender and without noticeable bumps or protrusions; head and first thoracic segment with pair of pointed horns
Alaska to Newfoundland, south to North Carolina, west to California
dry open mixedwood and pine forest, peat bogs, grasslands
adults fly during the day in May and June
larvae feed mainly on leaves of willow and Sweet Gale (Myrica gale), but also on alder, birch, Buffaloberry (Sherpherdia canadensis), gooseberry, New Jersey Tea (Ceanothus americanus), pine, and members of the rose family (Rosaceae)
associated with Labrador Tea (Ledum groenlandicum) and Bearberry (Arctostaphylos uva-ursi) in Alberta
Life Cycle
one generation per year; overwinters as a pupa
See Also
most similar to Hethemia pistasciaria but lacks the angular hindwings of that species (compare images of both species)
Internet References
live adult images by Anthony Thomas (Moth Photographers Group)
pinned adult image plus common name references, habitat, flight season, description, biology, distribution (G.G. Anweiler, U. of Alberta)
pinned adult image (Insects of Quebec)
distribution, habitat, food plants; PDF doc (J.D. Lafontaine and D.M. Wood, Butterflies and Moths of the Yukon)
food plants and flight season; PDF doc (Macrolepidoptera of Mont Saint-Hilaire Region, McGill U., Quebec)