Common NameCommon Grass-moth, Forage LooperSeasonalityAdults have been collected in Alberta from mid-June through mid-SeptemberIdentificationMedium-size (3.0-4.2 cm wingspan) broad-winged brown (female) or brownish-grey (male) moths. Males have two dark bars crossing the forewing, the innermost curving outward near the lower margin, but touching neither the outer band nor the lower margin of the wing. The subterminal band is reduced to a few small points except near the costa, where it forms two prominent black fused spots. The hindwing is light grey-brown with a dark sinuous subterminal band and dark terminal band. The female is dull grey-brown with the bars of the male forewing reduced to faint lines. The hindwing is also brown, and the terminal bands are much less contrasting than those of the male.
In the smaller and more common C. crassiuscula the forewing bars are wider and usually touch at the bottom, while the antemedian bar runs straighter and usually touches lower margin. Females of crassiuscula are smaller, browner and much more strongly marked than those of erechtea. Some males of the two species can be very difficult to identify, and the genitalia need to be examinined.
Scientific NameCaenurgina erechteaCommon Name
Common Grass-moth, Forage Looper
Habitat
Open areas such as pastures, meadows, roadsides, etc. with an abundance of grasses and forbs.
Seasonality
Adults have been collected in Alberta from mid-June through mid-September
Identification
Medium-size (3.0-4.2 cm wingspan) broad-winged brown (female) or brownish-grey (male) moths. Males have two dark bars crossing the forewing, the innermost curving outward near the lower margin, but touching neither…
Medium-size (3.0-4.2 cm wingspan) broad-winged brown (female) or brownish-grey (male) moths. Males have two dark bars crossing the forewing, the innermost curving outward near the lower margin, but touching neither the outer band nor the lower margin of the wing. The subterminal band is reduced to a few small points except near the costa, where it forms two prominent black fused spots. The hindwing is light grey-brown with a dark sinuous subterminal band and dark terminal band. The female is dull grey-brown with the bars of the male forewing reduced to faint lines. The hindwing is also brown, and the terminal bands are much less contrasting than those of the male.
In the smaller and more common C. crassiuscula the forewing bars are wider and usually touch at the bottom, while the antemedian bar runs straighter and usually touches lower margin. Females of crassiuscula are smaller, browner and much more strongly marked than those of erechtea. Some males of the two species can be very difficult to identify, and the genitalia need to be examinined.
Life History
The adults are active day and night. There are probably at least two broods in Alberta, as fresh adults have been found as late as September. The larvae are reported to hide by day and feed at night (Forbes, 1954).
Conservation
A common widespread species; no concern.
Diet Info
Clover (Trifolium) (Rockburne and Lafontaine, 1976); alfalfa (Medicago), grasses (Gramineae), ragweed (Ambrosia sp.) (Covell, 1984).
Range
Throughout most of the United States and Canada from Quebec west, north at least to the southern edge of the boreal forest in western Canada. Widespread in the southern half of Alberta, from the Milk River north to…
Throughout most of the United States and Canada from Quebec west, north at least to the southern edge of the boreal forest in western Canada. Widespread in the southern half of Alberta, from the Milk River north to at least the Nordegg, Edmonton and Lloydminster areas.
Citation
Page Citation for Caenurgina erechtea
Page Citation
"Species Details - Caenurgina erechtea, University of Alberta E.H. Strickland Entomological Museum." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/2-3715. Accessed 27 Mar. 2023.