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

Upcoming Events

Interested in a 2022 BugGuide gathering in New Mexico?

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 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.

Previous events


Species Petrophila canadensis - Canadian Petrophila - Hodges#4779

Unknown Moth - Petrophila canadensis Moth ID Please - Petrophila canadensis Crambidae: Petrophila canadensis? - Petrophila canadensis Moth - Petrophila canadensis Canadian Petrophila moth - Petrophila canadensis  Moths Petrophila canadensis - Canadian Petrophila - Hodges#4779 - Petrophila canadensis Petrophila ... ? - Petrophila canadensis Petrophila canadensis - Canadian Petrophila - Hodges#4779 - Petrophila canadensis
Show images of: caterpillars · adults · both
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 Acentropinae
Tribe Argyractini
Genus Petrophila
Species canadensis (Canadian Petrophila - Hodges#4779)
Hodges Number
Synonyms and other taxonomic changes
original combination Parargyractis canadensis Munroe, 1972
* phylogenetic sequence # 144100
wingspan 11-18 mm
Adult: forewing central area lacks triangular arrangement of 3 black spots, present in P. fulicalis; hindwing with two transverse brownish bands (proximal band broad, and distal one thin) separated by white space; trianglular patch of fine black speckling extends at least halfway down from costa of hindwing (may be hidden by overlapping forewing). Fine dark line capping the hindwing eyespots is usually more extensive (nearly complete) over all spots, but this can be a difficult mark to judge since the line wiggles close to the eyespots in the middle.(1)
southern Canada and northeastern United States: west to southeastern Manitoba and North Dakota, south to Tennessee and North Carolina (BG and iNaturalist data). Mapped MPG records in Alberta and Arizona almost certainly refer to other species in this group.(1)
larvae live inside underwater retreats (sheets of spun silk) on top of rocks in streams and rivers; adults can be found on nearby riparian vegetation during the day
adults fly from May to September (2 broods)
larvae feed preferentially on diatoms in the genera Navicula and Cymbella that become trapped in their silk sheets, and also scrape algae from rocks in streams and rivers
Life Cycle
larvae are aquatic, developing in riffles of streams and rivers; two generations per year; overwinters as an adult
See Also
Petrophila fulicalis on BG and Moths of Maryland.
Print References
Lavery, Michael A. & Costa, Robert R. 1976. Life History of Parargyractis canadensis Munroe (Lepidoptera: Pyralidae). Amer. Midl. Nat. 96:407-417.
Sexton, C. W., 2021. Identification and Distribution of the Petrophila fulicalis species group (Crambidae): Taking Advantage of Citizen Science Data. J. Lep. Soc. 75(2):113-127.(1)
Internet References
live adult images plus description, foodplants, flight season (Lynn Scott, Ontario) [LINK broken)
pinned adult image plus flight season (John Glaser, Maryland)