Species Details

Pediasia trisecta

University of Alberta E.H. Strickland Entomological Museum Read more about this collection »

Common NameGreater Sod Webworm SeasonalityJuly to September. IdentificationA large crambid (23-33 mm wingspan). Forewings varying from brown to pale ochreous, lighter in the lower half, surface sprinkled with dark brown scales; with dark lines from the base through the cell and a dark area closer to the margin; with an oblique line from the cell to the apex; terminal line with 4-5 dark dots; fringes steel gray cut by four or five white lines. Hind wings light brown to pale grayish white, fringe whitish. Distinguished from the other Pediasia species by the combination of dark areas in the forewing and the lighter fringe which is cut by white lines. Worn specimens can be hard to identify. The male genitalia are illustrated in Landry (1995). Pediasia aridella edmontella also has white streaks in the fringe and outer margin of the forewing but it lacks the pronounced dark lines.

Scientific Name Pediasia trisecta Common Name Greater Sod Webworm Habitat Grassland areas. Seasonality July to September. Identification
A large crambid (23-33 mm wingspan). Forewings varying from brown to pale ochreous, lighter in the lower half, surface sprinkled with dark brown scales; with dark lines from the base through the cell and a dark area…
A large crambid (23-33 mm wingspan). Forewings varying from brown to pale ochreous, lighter in the lower half, surface sprinkled with dark brown scales; with dark lines from the base through the cell and a dark area closer to the margin; with an oblique line from the cell to the apex; terminal line with 4-5 dark dots; fringes steel gray cut by four or five white lines. Hind wings light brown to pale grayish white, fringe whitish. Distinguished from the other Pediasia species by the combination of dark areas in the forewing and the lighter fringe which is cut by white lines. Worn specimens can be hard to identify. The male genitalia are illustrated in Landry (1995). Pediasia aridella edmontella also has white streaks in the fringe and outer margin of the forewing but it lacks the pronounced dark lines.
Life History The early stages have been described by Felt (1894) and Ainslie (1927). May be two brooded. It can cause economic damage to lawns. Conservation Of no concern. Diet Info No local information, but said to be grass by Fernald (1896). Range A North American species that is widespread across southern Canada and in the northern part half of the United States. In Alberta, it occurs throughout the prairies and the aspen parkland.
Photo by Charlie Bird
Photo by Charlie Bird

Citation

Page Citation for Pediasia trisecta

Page Citation

"Pediasia trisecta, University of Alberta E.H. Strickland Entomological Museum." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/2-2921. Accessed 16 Oct. 2021.

Taxonomic Hierarchy

Kingdom Animalia Phylum Arthropoda Class Hexapoda Subclass Insecta Order Lepidoptera Suborder Ditrysia Superfamily Pyraloidea Family Crambidae Subfamily Crambinae Genus Pediasia Species Pediasia trisecta
This hierarchy is created from our museum records, it may not always accurately reflect modern taxonomies.

Taxonomic Hierarchy for University of Alberta E.H. Strickland Entomological Museum