Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
Upcoming Events

BugGuide is a National Moth Week Partner. How to add your National Moth Week 2021 photos. July 17-25.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

National Moth Week 2020 photos of insects and people.

Photos of insects and people from the 2019 BugGuide Gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Previous events


TaxonomyBrowse
Info
ImagesLinksBooksData

Genus Pediasia

Unknown Moth - Pediasia trisecta Pediasia trisecta - Sod Webworm - Hodges#5413 - Pediasia trisecta Crambidae: Pediasia trisecta? - Pediasia trisecta Agriphila vulgivagellus – Vagabond Crambus Moth 5403 ? image 2 - Pediasia abnaki Moth - Pediasia trisecta 5413 – Pediasia trisecta – Sod Webworm - Pediasia trisecta NMW2018 Moth #12 - Pediasia trisecta Crambid Snout Moth - Pediasia dorsipunctellus
Show images of: caterpillars · adults · both
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Pyraloidea (Pyralid and Crambid Snout Moths)
Family Crambidae (Crambid Snout Moths)
Subfamily Crambinae (Crambine Snout Moths)
Tribe Crambini (Grass-Veneers)
Genus Pediasia
Numbers
8 species in North America listed at All-Leps
Size
wingspan 20-33 mm
larvae to 28 mm
Identification
Adult: forewing slender, variably brown to gray; hindwing broader than forewing, usually paler, and with prominent fringe of hair-like scales; labial palps project foreward, forming a "snout" (as in other members of this subfamily)

Larva: body pinkish-white to yellowish to light brown, often with paired dorsal and lateral spots on each abdominal segment; head yellowish-brown, brown, or black
Range
all of United States and southern Canada
Habitat
lawns, grassy areas; adults may fly low over lawns during the day, but are primarily nocturnal and attracted to light
Season
adults fly from May to October
Food
larvae feed on grasses (Poaceae)
Life Cycle
sod webworms overwinter as young larvae a few centimeters below soil line among roots of weeds and grasses in silk-lined tubes; in early spring, larvae feed on upper root systems, stems, and blades of grass; they build protective silken webs, usually on steep slopes and in sunny areas, where they feed and develop; pupation occurs in May in underground cocoons made of silk, bits of plants, and soil; adults emerge about two weeks later, are erratic and weak flyers, live only a few days, and feed solely on dew; they rest in the grass or sometimes fly low over the ground during the day, but are primarily nocturnal, becoming active at dusk.
Eggs are deposited indiscriminately over the grass, and hatch in 7-10 days; the most severe damage to turf occurs in July and August when the grass is not growing rapidly; during this hot weather, larvae feed at night or on cloudy days; most species complete 2 or 3 generations per year, with approximately 6 weeks elapsing between egg deposition and adult emergence.
[adapted from text by North Carolina State U.]
See Also
other genera in the tribe Crambini (see MPG page)
Internet References
live and pinned adult images of Pediasia trisecta by various photographers (Moth Photographers Group)
pinned adult image of Pediasia trisecta plus description, distribution, flight season, biology (Strickland Entomological Museum, U. of Alberta)
biology of webworms in general including Pediasia trisecta (North Carolina State U.)